How to build a house without a foundation: old and modern ways. The history of a log house - the foundation in the old days They were formed on an ancient foundation

14.07.2008 14:12:38

One of the greatest authorities in the history of architecture, the Italian Renaissance architect Andrea Palladio, argued that of all the mistakes that occur at a construction site, those that relate to the foundation are the most pernicious, since they entail the death of the entire building and are corrected with the greatest difficulty. That is why the usually restrained Palladio demanded that the architect devote "all his attention to this subject"!

Wise Rudaki, understanding the significance of the foundation, also advised:

“Lay firm foundations for buildings:

The foundation for a building is like a guard."

And the evil tongues of contemporaries attribute the “fall” of the famous leaning tower in Pisa to the fact that the unlucky architect Bananuus simply saved on the foundation, trying to increase his income.

The foundation, as the ancient treatise tells, is the foundation of the building, i.e. that part that is in the ground and bears the weight of the whole building, visible above the ground. In some places, the foundations are given by nature itself, in others you have to resort to art.

The most ancient Egyptian temples, despite their massiveness, were built in such a way that their inner walls had no foundations at all. Over time, attitudes towards foundations have changed. Already in the IV century. BC. not only the outer walls of the premises rested on a solid foundation of two- or three-layer masonry, going into the ground by almost 1.4 m. The foundation began to be laid over the entire area of ​​​​the building. The famous temples of Ramesses IV at Dar el-Bahri and Nectaneb II at el-Kab stand on an eight-layer foundation, forming a massive platform. In ancient Greece, foundations were usually not built solid, but only under walls and separate supports.

Various types of foundations. Here, for example, huts made of wood, branches and leaves in the villages of Malonesia on the Trobian Islands in Oceania rest on powerful stone slabs or on piles, rise 2 m above ground level. Only in New Zealand are they slightly deepened into the ground. Today, 18,000 Malanesians live in houses on stilts driven into the bottom of the bay.

Sometimes dwellings were located on rafts, sometimes on special platforms supported by piles, on embankments or dams in the middle of the water. This type of dwelling exists in different parts of the globe and today among peoples engaged in fishing. The researchers found that Europeans built similar and more primitive dwellings more than 16 millennia ago.

Scientists suggest that pile buildings are an elementary protection against animals, people, and tides of water. And semi-sedentary hunters used living trees as a foundation, arranging their strong dwellings on them, like bird nests. Here, perhaps, the concern for safety really prevailed.

Houses in Venice are built on long pine and oak piles connected by a complex lattice system. Under the foundation of only one church, Santa Maria della Salute, built in the 17th century, 110 thousand piles were used. During the restructuring of the Peter and Paul Fortress into stone, begun in 1706. and which lasted more than 30 years intermittently, about 40 thousand piles were driven. In the XVI century. in Holland, for the construction of the foundation of the Amsterdam City Hall, it was necessary to drive over 13 thousand piles into the soil saturated with water.

This was a very difficult matter, because only in the XIX century. piles began to be driven into the ground with a steam pile driver (for 1 hour 10-15 piles, depending on the soil), and before that they were driven only by hand.

Piled buildings in Europe testify not only to building techniques, but also to the strength of primitive communal orders. In order to cut and sharpen with a stone ax hundreds,

And sometimes thousands of piles, to deliver them to the shore of the lake and drive them into the marshy soil, a huge amount of labor was required. There had to be a well-organized team and a skilled "foreman". In those distant times, such collectives could only be a tribal community, soldered not only by blood ties, but also by collective production.

Their buildings were found in Northern Italy, Southern Germany, in Northern Europe - from Ireland to Sweden, their remains - in the Vologda region and in the Urals.

In the Late Neolithic, capital foundations began to be built: the space between the outer walls of the foundation was covered with stone and rammed with clay.

Building on piles, known since ancient times, is used in the most daring projects of the future, for example, in the projects of cities built among the sea.

In Rus', log cabins of residential and public buildings as early as the 17th century. More often they were placed on the ground without foundations, in connection with which the lower crowns were cut from condo pine or larch and rested in the corners on boulder supports. Massive foundations were also built from crushed sandstone or limestone in mortar to a depth of 90-120 cm and other, more complex foundations. One of these foundations was erected under the walls of the unique Church of the Intercession on the Nerl near Vladimir. The cobble stone foundation was laid to a depth of 1.6 m, and its sole rested on a layer of hard-plastic clay. The old masters showed a good knowledge of building geology. Under the foundation, the base of the walls 3.7 m high was erected in two steps from hewn stone. Outside and inside, these walls were sprinkled with clayey sandy loamy soil, then the soil was tightly compacted. Thus, the foundation of the temple was at a depth of 5.3 m inside an artificial hill.

In the construction of the Assumption Cathedral in Moscow in 1475. Fioravante "by his cunning" was the first to use a deep foundation (over 4 m), under which oak piles were previously hammered. After 500 years, a huge Ostankino tower 536 m high was built in Moscow. The tower, whose weight together with the foundation was 51,400 tons, was erected on a monolithic reinforced concrete ring foundation 9.5 m wide, 3 m high and 74 m in diameter (circumscribed circle). The foundation is laid in the ground to a depth of only 4.65 m.

By order of Peter I, written instructions were drawn up on how to lay the foundation. Many old construction estimates are known, which describe the foundations.

In Russia, the first manual on the choice of foundations and the arrangement of foundations appeared in the first quarter of the 18th century.

For the construction of large railway bridges, which unfolded at the end of the first half of the 19th century, it was necessary to develop scientifically based methods for constructing bases and foundations.

One of the founders of the science of foundations and foundations in Russia was engineer M.S. Volkov, who in his works “On the study of soils of the earth, produced in the art of building” (1835) and “On the foundations of stone buildings” (1840) gave a coherent theory of foundations and foundations, the scheme and main part of which have been preserved to this day.

The first systematic course on foundations and foundations, compiled by prof. V.M. Karlovich, was published in 1869.

The determination of the minimum foundation depth from the foundation strength conditions was first given in the 60s of the last century by prof. G.E. Pauker. This question was experimentally investigated by Prof. IN AND. Kurdyumov, who found that when a rigid foundation is pressed into loose soil, curvilinear sliding surfaces are formed in the latter. Kurdyumov's experiments are described in his work On the Resistance of Natural Foundations, published in 1889.

An important task in the 20th century was the creation of a theory for calculating bases and foundations.

In 1914 prof. PA Minaev, on the basis of experimental work, showed the possibility of applying the theory of elastic bodies to determine stresses and strains in bulk solids. This made it possible to use the theory of elasticity as a theoretical basis for soil mechanics. This was also supported by the work of Prof. K. Terzaghi "Construction mechanics of soils on a physical basis".

In the Soviet Union, soil mechanics has been greatly developed in connection with the enormous tasks set before the builders by the plans of the national economy. For their implementation, it was necessary to solve many complex problems of foundation engineering.

Foundation structures.

The foundation is called the lower (underground or underwater) structure of a building or structure, which is designed to transfer the load from the building or structure to the base. Foundations must be strong, durable and stable, frost-resistant, able to resist the action of aggressive groundwater, and also economical.

By design, the foundations are tape, pile, columnar and slab solid. Pile foundations are used when it is necessary to transfer significant loads to weak soil.

According to the material, piles can be wooden, steel, concrete, reinforced concrete and combined. The most widespread are reinforced concrete piles of square and round sections, solid and hollow. Depending on the size, piles are short (3-6 m) and long (6-20). Depending on the transfer of load to the ground, piles-racks and hanging piles are distinguished. The former pass through weak soils and rest on solid soil, transferring the load to it; hanging piles compact the loose soil during driving, and transfer the load to it due to the friction forces that arise between the side surfaces of the piles and the layer of loose soil.

According to the method of manufacture and immersion in the ground, piles are driven and stuffed. Driven ones are made in advance and immersed in the ground with a hammer, indentation or vibration. Stuffed piles are arranged on site by filling holes in the ground with concrete or reinforced concrete. On top of the piles, they are connected with a beam or reinforced concrete slab, called a grillage. The load-bearing structures of the building (structure) are supported on the grillage, and it ensures uniform transfer of loads to the piles. The grillage is made monolithic or prefabricated (from reinforced concrete head elements).

According to the location of the grillage, the foundations are with low and high grillage. In the first case, the pile heads are buried below the ground surface, in the second case, the pile heads are located above the ground surface. Pile foundations do not require large volumes of excavation work; they are economical in terms of concrete consumption, industrial and significantly reduce labor costs and construction costs.

The depth of the foundation is the distance from its sole to the planned soil surface, determined by the norms. According to the depth of laying, the foundations are shallow - up to 4-5 m and deep - more than 5 m.

By type of material, strip foundations are reinforced concrete, concrete (prefabricated and monolithic), rubble concrete, rubble.

Strip foundations are the most common, as they are used in the construction of buildings with load-bearing walls of various heights. As a rule, prefabricated strip foundations made of reinforced concrete cushion slabs (FL) (GOST 13580-85) and foundation wall blocks (FBS) (GOST 13579-78) are used for buildings for residential and civil and cultural purposes. Cushion slabs of strip foundations are sole elements with a relatively short length of cantilevers, the cross section of which is determined by the magnitude of the transverse force. In these elements, the high strength properties and advantages of prefabricated reinforced concrete are not implemented efficiently enough, which negatively affects the cost of foundations.

The cost of prefabricated strip foundations for low-rise buildings, depending on engineering, geological and climatic conditions, is 25-45% of the total building costs. The high cost of strip foundations is explained by the fact that foundation concrete blocks (FBS) are uneconomical in terms of concrete consumption, since their bearing capacity is used by about 10%. Foundation blocks are able to withstand the weight of a building of 14 floors or more, while at present in small towns mainly 5-9-story buildings are being built, and in the suburbs and rural areas low-rise construction dominates - cottages and manor-type houses.

Columnar foundations of one-story and low-rise buildings are made of standard concrete blocks FBS 9.5 or FBS 9.4, installed on reinforced concrete slabs (FL) 1.2 m long. Standard load-bearing lintels or foundation beams are used to support the walls. The pitch of the pillars for low-rise buildings is taken as 2.4-3.6, and for one-story industrial buildings - 6.0 or 3.0 m.

Pillars are installed at the corners of buildings, at the intersection of walls and under load-bearing walls. The use of columnar foundations for low-rise buildings is economically feasible if solid soils lie at a depth of 2.4-3.0 m.

The load transmitted by the foundation causes a stress state in the foundation and deforms it. The depth and width of the stressed zone significantly exceed the width of the base of the foundations. As we go deeper below the base of the foundation, the area of ​​stress propagation expands, but to a certain limit, and their absolute value decreases. For example, if the stress under the base of the foundation is taken as one, it decreases to 0.34 for a square foundation in plan and to 0.55 for a strip foundation.

Deformations of the base, which occur mainly due to soil compaction, cause the building to settle. The settlement is uniform, when all elements of the building are lowered equally over its entire area and there are no additional stresses in the building structures, and uneven, when individual elements of the building are lowered to different depths relative to each other. In this case, additional stresses may arise in the building structures. Depending on the unevenness of the settlement, additional stresses can either be safely absorbed by the building, or can cause cracks, deformations, and even destruction of the building.

Thus, the main danger for the safety of the building and its protection from the appearance of cracks and damage that are unacceptable for normal operation of structures is not so much the settlement of the base as its unevenness.

Solid foundations are arranged in the form of a massive monolithic slab under the entire building. Such foundations provide uniform settlement of the entire building, protect basements from backwater groundwater. They are erected on weak or heterogeneous soils under significant loads. A monolithic reinforced concrete slab is most often arranged as a solid one and less often as a ribbed one.

The foundations of the building can act as the walls of the basement floor. The technical underground is a room that is used to house engineering equipment and lay communications. Foundations, walls and floors of basements must be isolated from surface water seeping through the ground, as well as from capillary rising ground moisture.

Isolation from ground dampness and groundwater of underground structures of buildings and structures is achieved by using dense monolithic concrete with plasticizing or water-repellent additives or a waterproofing device. When using ordinary concrete or masonry from other materials (brick, rubble stone, etc.), waterproofing is done with cement-sand, asphalt, coating (hot bitumen, cold polymer bituminous mastic-elastom), pasting in several layers (roofing material, roofing felt, hydroisol, metal isol, borulin). When protecting against ground dampness and with low groundwater pressure, pasting or coating waterproofing is used, which is not always of high quality.

When the groundwater level is below the level of the basement floor, horizontal and vertical waterproofing is arranged. Horizontal waterproofing is created by preparing a concrete preparation and a waterproof basement floor, for example, an asphalt one, by laying a continuous pasting tape made of rolled materials in two levels in the outer and inner walls. The first pasting layer is laid at the level of the basement floor, the second - below the basement floor. Vertical waterproofing of basement walls is carried out by coating their outer surfaces with hot bitumen, special mastic.

When the groundwater level is located above the basement floor for waterproofing, it is necessary to create a kind of "shell" that can resist the pressure of groundwater. At high groundwater pressures, waterproofing is arranged along the inner surface of the basement walls, and a reinforced concrete slab is laid on top of the floor waterproofing.

In the fight against groundwater, a drainage device is very effective. Drainage is carried out as follows: ditches are dug around the building at a distance of 2-3 m from the foundation with a slope of 0.002-0.006 towards the prefabricated drainage ditch. Pipes with holes are laid along the bottom of the ditch to drain water. Ditches with pipes are covered with gravel, coarse sand, then soil. Water flows through the drainage pipes into a river or into a certain low place, for example, into a ravine.

During construction on heaving soils, until recently, the main event was the laying of foundations below the estimated depth of seasonal freezing. However, for lightly loaded foundations of low-rise buildings, this leads to their rise in price by 25-50%. With an increase in the depth of laying, the action of normal forces on the sole stops. But the tangential forces of heaving along the side surfaces of the foundation increase significantly.

In low-rise buildings, these forces usually exceed the load acting on the foundations, as a result of which the latter are subjected to heaving, i.e., they are deformed. Ultimately, this brings the walls of the building into disrepair. Therefore, at present, in the construction of low-rise buildings, it is advisable to use slightly ruined foundations that provide:

Reducing the cost by reducing labor intensity, concrete consumption and the timing of the production of zero-cycle works;

Sufficiently complete use of the bearing capacity of soils and foundation materials;

Reducing the volume of formwork, reinforcement and earthworks;

The ability to perform foundations with almost the same efficiency in various weather and soil conditions.

Foundation construction belongs to the category of work of increased responsibility, where deviation from the requirements of regulatory documents is fraught with the most serious consequences. There are a large number of examples when violation of the rules of design and production of works led to deformations of buildings, and, consequently, to high material costs.

In order to choose a rational foundation for a building that corresponds to the geological conditions of the building site, and to avoid mistakes during construction with their possible consequences, it is necessary to know the basic rules and principles that should be followed when solving this issue. It is useful for every specialist builder and individual developer to know:

The foundation is a very responsible underground structure of the building, on which strength, durability and stability depend.

The basis of the foundations should be continental (not disturbed) soils, preferably dense. It is not recommended to build a house on bulk and subsidence soils without their preliminary compaction.

Starting to design foundations. It is necessary to have accurate data on the base soils (sandy or clay, heaving or non-heaving, swelling or subsidence) in order to take structural measures to ensure the reliability of the structure, acceptable uniform precipitation and the strength of the building as a whole.

In ancient times, architects attached great importance to the study of the properties of the foundation soils of the building, as they well understood that negligence in such a matter could lead to deformation of the structure and even to an accident. It is very dangerous to underestimate the physical and mechanical properties of soils and the hydrogeological conditions of the development area. Serious accidents, which have become more frequent over the past 35 years in domestic construction practice, are convincing proof of this.

Back in the 1st century BC. e., 2000 years ago, the Roman architect Vitruvius in his writings paid special attention to the fact that mistakes and omissions lead to severe catastrophic consequences for structures.

The architect Leon Battista Alberti (15th century) said: “Swarm for good and happiness until you reach a solid one, and if a mistake is made in anything else, it is less harmful, easier to correct and more tolerable than in grounds where it is impossible to make no apology for the mistake."

The outstanding Italian architect and builder A. Palladio, in a treatise written in 1570, attaching particular importance to the issues of building foundations on a solid foundation, wrote: the death of the whole building is behind them and are corrected only with the greatest difficulty.

Peter I in the “Construction Regulations” noted: “There is no need to spare any work or dependency for the construction of the sole (base) and forgery (foundation). However, when designing, it is necessary to use the most rational designs of foundations, which make it possible to reduce construction labor intensity, material consumption, time and cost of work.

The old rule “they don’t save on foundations” should not be guided by. The consumption of materials for foundations is determined by the calculation and design requirements for each specific case. An excess amount of materials is an additional cost of materialized and living labor, and, consequently, unjustified material costs.

Attaching great importance to the problems of resource saving and reducing the cost of human labor, scientists and engineers are currently paying serious attention to improving the design of foundations for low-rise buildings and the technology of zero-cycle work.

Reducing the consumption of materials, labor intensity and the cost of the zero cycle of one-, two-story buildings is achieved by compacting the natural base in order to increase the bearing capacity of the soil, as well as through the use of efficient foundation designs.

The task of the engineer designing the foundations is to find an effective solution. This is possible only with a correct assessment of the engineering and environmental conditions of the construction site and the operation of the foundation soils together with foundations and above-ground structures, as well as when choosing a foundation construction method that guarantees the preservation of the natural structure of the foundation soils.

For the quality of projects in the old days they asked strictly. The decree of Peter I read: “All the ranks in the service, as well as manufactories-advisers and other people of various fishing establishments, should remember that all projects are great, serviceable, must be, so as not to ruin the treasury in vain and not damage the fatherland. And whoever begins to blurt out projectiles, I will deprive him of that rank and order him to fight with a whip. Therefore, there are unshakably solid, beautiful buildings built more than 250 years ago by architects M. Kazakov, V. Bazhenov, A. Voronikhin, A. Zakharov, S. Chevaskinsky, D. Trezzini, K. I. Rossi, F. B. Rastrelli , A. Rinaldi, Montferrand, Quarenghi, Cameron and others.

A completely different picture is emerging at the present time with the mass development of districts with residential low-rise buildings.

As an inspection of the development of several cottage settlements in the Moscow region revealed, design work, as a rule, was carried out in these cases by non-specialized organizations and without preliminary engineering and geological surveys.

As a result, the foundations were made without taking into account the specifics of soils, their properties and existing loads, both from the supporting structures of the house and from the action of frost heaving forces (normal and tangential forces).

Without professional knowledge about soils and their properties, it is simply impossible to choose a rational and sustainable foundation design and avoid unforeseen consequences.

Numerous examples show that deformations of the load-bearing and enclosing structures (walls) of houses occur due to errors made during the construction of foundations and due to frost heaving of clay soils.

Frost heaving is expressed, as a rule, in the uneven rise of a layer of frozen soil, and the stresses that arise in the soil during heaving have a significant impact on the foundations and ground structures of the building. Particularly affected by this house with a basement, the walls of which are made of prefabricated blocks.

Construction on sandy soils eliminates such consequences, since sands are non-cohesive soils that filter moisture. Therefore, it is easier and cheaper to build on the sands.

In areas with clay soils, sandy cushions, poured with layer-by-layer compaction, are a reliable foundation for foundations.

In all cases, before building your own house, you need to know the geological conditions of the building site, at what depth do solid soils and groundwater lie.

Many developers are still paying for these mistakes: at unfinished country houses, the foundations rise and deform due to frosty heaving of clay (heaving) soils, as a result of which cracks appear in the walls, groundwater floods the basement, the walls of which are usually made of prefabricated blocks, etc.

There is only one reason for all this - the foundations were made illiterately - without taking into account the specifics of soils, without observing design standards. And this is very important, since the cost of foundations is approximately 1/3 of the cost of building a building box.

Foundations of low-rise buildings.

Economical foundations of low-rise buildings and manor houses.

The reason for the high cost of the foundations of low-rise and one-story houses, which are now being built everywhere, is that they are made from the same standard prefabricated blocks that are used for the foundations of multi-storey buildings of 9-12 floors or more.

The bearing capacity of concrete blocks is used by about 10%, as a result of which the consumption of concrete, the cost of foundations and 1 sq. m of living space.

To this it is necessary to add the dispersal and low volume of work, as well as the remoteness of objects from the bases of the construction industry and the low level of mechanization of construction and installation works.

Reducing the consumption of concrete and the cost of foundations of low-rise buildings is a very urgent problem at the present time, since only in the Moscow region before 2000, 145,200 cottages with a total area of ​​16 million square meters were built.

Strip foundations of residential and public buildings with a basement, as well as industrial buildings without a basement, which are the most common in design and construction practice, are usually prefabricated, regardless of the number of storeys. However, this does not take into account that prefabricated foundations have significant drawbacks that have a very negative impact on the quality of the foundation structure as a whole. Designers and builders never paid attention to this. Assembly strip foundations are massive and not economical, since in essence they are monolithic foundations, cut into small elements - blocks, but only more expensive and of poorer quality due to the large number of seams and local seals made by hand. As a result, the labor costs for the construction of foundations increase significantly, and, consequently, the terms for completing the zero cycle as a whole. With strip foundations, the construction of a basement or underground in manor houses is justified not only constructively, but also economically, since the additional costs associated in this case with the implementation of a basement insulated floor are 3-5 times less than those required to obtain the same useful area in a room specially built for this purpose. The height of the basement in this case is taken as a minimum -1.8-2.0 m.

According to the technology of zero-cycle work traditionally adopted by us, strip foundations are first erected, and then concrete preparation under the basement floors on bulk soil, since the floor level is located 75-90 cm or more above the base of the foundations (depending on the thickness of the slabs, pillows and laying depth). Such a foundation design and traditional work performance technology increase the complexity of the zero cycle, as this is associated with additional labor costs for backfilling the pit with its compaction in order to avoid basement floors during operation.

In addition to the fact that this technology increases the labor intensity of the work, it does not ensure the operational reliability of the basement floors due to the inevitability of subsidence of bulk soils compacted without the use of rammers. There are none at our construction sites, and this has a detrimental effect on the quality of soil compaction work. The basement floors deformed as a result of this on bulk soil often have to be repaired or rebuilt, which is associated with additional material costs during the operation of the building and with certain difficulties. For the same reason, the blind areas around the building are deformed, and storm drains soak the bases of the foundations.

In all civilized countries, pneumatic rammers have been used in construction for more than 75 years. These shortcomings can be avoided and the labor intensity and cost of the zero cycle can be reduced only in the case of foundations in the form of a solid reinforced concrete slab, which simultaneously performs the functions of a foundation and a basement floor, as is customary for high-rise buildings.

For wooden and brick low-rise buildings and manor houses, it is advisable to make basement walls of rubble concrete of variable section, the laying depth of which for the central regions is taken at 1.30-1.45 m with the floor located 0.90 or 1.05 m above the level of planning marks and 1.60-1.75 m with a difference between the floor and the ground of 0.75-0.60 m.

The walls of the basement, in order to avoid their freezing and heat loss, must be reinforced from the inside with sheets of foam plastic 20 m thick on bituminous mastic, followed by plastering on a mesh - chain-link. Such foundations are 20-25% more economical than traditional tape foundations in terms of concrete consumption and labor costs. This is especially important for individual developers in today's conditions of high cost of building materials.

The complication of the form of the basement of the building in this case is justified by reducing the consumption of material (concrete) and cost, as well as improving the appearance of the building.

The depth of the foundation is taken depending on the depth of seasonal freezing of the soil and the level of groundwater. The depth of laying the base of the foundations, m, is accepted: for Astrakhan, Minsk, Kiev and Vilnius -1.0; for Kursk, Kharkov and Volgograd -1.2; for the Moscow region, Voronezh, St. Petersburg and Novgorod -1.4 ; Vologda, Saratov and Penza -1.5; for Ulyanovsk, Samara, Kazan and Kotlas -1.7; for Aktobe, Ufa and Perm -1.8; for Kustanay, Kurgan and Ukhta -2.0.

The foundations of the proposed design must be made from the device of a reinforced concrete slab - the basement floor. In this case, the floor structure also performs the function of the foundation plate, on which the basement walls rest. The thickness of the basement walls in this case is taken depending on the climatic regions, but not thinner than 30 cm. It is best to make the basement walls monolithic, since they are almost waterproof and almost half the price of prefabricated ones. Concreting of walls must be carried out with the help of solid planed formwork, so that after stripping the walls, the surfaces of the walls should not be leveled with plaster or grout.

Vertical waterproofing is performed with bituminous mastic, which is applied to the outer surfaces of the walls in two steps. To protect the basement from moisture (when it is unavoidable) you can use a clay castle made of soft clay. This method has justified itself for many centuries and is successfully used at the present time.

The slab-foundation is taken with a thickness of 20-25 cm and reinforced with a mesh with a cell of 15x15 cm or 10x10 cm from reinforcement 10AIII or 8AIII.

Concreting of the slab is carried out according to concrete preparation (100 mm) or waterproofing from two layers of roofing felt or roofing material, which prevents the rise of capillary moisture and retains the cement milk of the concrete mixture during concreting. In conditions of sandy or sandy loamy soils, the waterproofing device is preceded by compaction of the base soils with crushed stone, poured with bituminous mastic. In this case, the concrete of the slab does not dehydrate and retains its properties - strength and density, which is very important for the construction of foundations.

Such a constructive solution and the recommended technology for erecting foundations for low-rise buildings with a basement make it possible to reduce concrete consumption by 25% compared to the traditional solution. At the same time, the volume of earthworks is also reduced by 20-25% due to the exclusion of the broadened part of the foundation. As a result, the labor intensity and cost of the zero cycle are significantly reduced, which is very important for individual developers.

In some cases, when it is necessary, the waterproofing of the basement walls can also be pasted with a pressure brick wall. In this case, brick walls half a brick thick are first laid out, which are pasted over from the inside with 2-3 layers of roofing material. In the future, monolithic basement walls are made using only internal formwork, and brick walls pasted over with roofing material are used as external ones. This technology guarantees reliability and high quality waterproofing.

Reducing the consumption of materials and labor costs of the zero cycle of low-rise buildings and manor-type houses is achieved by making basement walls prefabricated - monolithic from blocks 30 cm thick. To support walls 51 and 64 cm thick, a monolithic belt (grillage) with a section of 30x50 or 30x65 cm is provided. 38 cm monolithic belt is not required to be reinforced. The device of such foundations is simplified, since this eliminates the dressing of seams and local sealing with concrete and brick in the places of holes and openings left for the entry of communications. To enter pipelines in monolithic sections, inlet pipes are laid. In this case, the consumption of concrete is reduced by 33%, and the cost is 1.5 times lower compared to the option of blocks with a thickness of 50 cm, since more than half of the prefabricated blocks are replaced by monolithic concrete, which is much cheaper than prefabricated. The permeability of basement walls when coated with bituminous mastic in this case is almost eliminated.

Thinned prefabricated-monolithic foundations are made on a solid reinforced concrete slab, which serves as the foundation and basement floor. Combining the functions of the construction of the basement floor and the foundation slab is economically feasible, since it does not require broadening of the base with a minimum thickness of the basement wall.

Thinned prefabricated-monolithic foundations are technologically advanced and effective for 5- and 9-storey buildings, but they are still inferior in cost to monolithic ones. With a high price of materials, such a solution will help reduce their consumption and reduce the cost and timing of the zero cycle while improving quality.

The widespread introduction of resource-saving technologies and structures in the mass construction of low-rise buildings will ensure the fulfillment of the tasks set.

The use of strip foundations is also advisable for buildings without a basement, built on dry, non-heaving (sandy) soils. The depth of the foundation in this case, regardless of climatic conditions, is taken to be less than 1 m. On clay or heaving soils (with a laying depth of more than 1 m), it is easier and cheaper to make a strip foundation on a sand cushion.

Foreword

A rubble foundation is a foundation for a building, almost 90% made of rubble. The main advantages of a rubble stone foundation are savings in building material, aesthetic appeal and, most importantly, reliability.

Necessary tools and materials

Concrete mixerBucketWaterStonePickShovelPerforator bladeMaster OKPerforatorExtensionCement

Content

A rubble foundation is a foundation for a building, almost 90% made of rubble. The main advantages of a rubble stone foundation are savings in building material, aesthetic appeal and, most importantly, reliability. Stone foundations for a house have been built for several centuries, and such a long-term practice of using rubble speaks in favor of this material for itself.

Any construction begins with laying a solid foundation, which no one advises to save on. According to the materials used, the foundations are divided into six types: sand, brick, rubble, concrete, block, reinforced concrete. In the old days, houses were built on stone foundations, in which they tried to lay large stones of block-like or block shapes. The stones of these foundations almost always exceeded the size of rubble stone, so they are properly called simply stone foundations. Such foundations are the most ancient and now they are rarely made. Stone foundations are the 7th type of existing foundations, which should rightfully be number 1. The most reliable houses are those built on eternal foundations - on rocks, where the rock itself is the foundation. But this is no longer a foundation as such, but a natural foundation.

The difference between stone and rubble foundations lies in the size of the stones used for them. As you know, rubble stone reaches 50 cm in size. Stones larger than half a meter are blocks, blocks (large), boulders, etc. - depending on their shapes and masses. Therefore, when laying rubble foundations, if stones of different sizes are available, then why not use them all, not particularly bothering yourself with how such a foundation will be correctly characterized.

How to make a strip stone foundation

According to their design, the foundations are divided into columnar, tape and slab. Stone foundations can be either strip (continuous) or slab - for example, consisting of several dug-in blocks at the corners of the house. Strip stone foundations are laid under houses with heavy slabs and heavy walls. The tape construction of the foundation takes on the maximum load from the building.

Stone foundations require, on the one hand, a serious responsibility, on the other hand, not the most complex preparation and experience of the performer. Foundations made of granite rubble, cobbles, boulders, blocks or blocks are among the most reliable, especially if they are made in heaving soils (clay, loamy, sandy, and silty sands). Such soils are insidious in that in hot weather they shrink, and when freezing, especially if after rains, they swell, dramatically changing their volumes. At the same time, the forces that act on the foundation reach 6-10 tons per square meter of the foundation.

Before making a stone foundation, the surface is leveled in the selected area, then the contours of the future foundation are marked. The contours of the foundation are marked with a strong twine stretched above the ground and tied to driven pegs.

Sometimes this operation is replaced by a cast-off device - a series of posts with boards nailed on top. The cast-off should be slightly higher than the future proposed base and a meter and a half from the outer edges of the trenches dug under the foundation. The cast-off can be either continuous or partial, around the corners of future walls. In this case, the cast-off conveniently replaces the pegs that need to be driven into the ground to pull the twine (or fishing line), since now the twine can be conveniently fixed on the cast-off boards and check the correct directions and sizes of the foundation contours and its angles.

Accurately mark the corners of the foundation (respectively, the walls of the building) at 90 ° will help the knowledge of the so-called "Egyptian triangle", in which the aspect ratio is 3:4:5 meters. Such a triangle is made with the help of stretched twine of the appropriate footage or knocked down from slats, boards.

The uniformity of vertical marks along the top corners of the future foundation (zero cycle) is checked using a water level.

After breaking down the foundation and carefully checking the dimensions, the accuracy of the corners of the foundation and the width of its walls (which can be 20-30 cm wider than the walls of the house), they begin to excavate. After digging the foundation trenches a little, you can remove the marking twine that interferes with work.

Foundations for houses are laid below the level of soil freezing. The depth of such a foundation depends on the number of storeys of the future house and the nature of the soil.

After excavation, the bottom of the trenches must be covered with sand. The thickness of the sand layer should be at least 10 cm. Then, using the fruits of modern civilization, the bottom and walls of the trenches can be covered with PVC film or a simple polyethylene film so that the edges of the film pieces overlap each other by 30 cm. edge of trenches with stones or bricks (press down). Such an operation will extend the integrity of the foundation for actually centuries, since cellophane will save the foundation from stronger adhesion to heaving soil and groundwater, and will also allow all the components that strengthen the foundation to be preserved in the base. So that the film laid in the trenches does not bristle, it can be immediately crushed with large stones by surprise.

If it is decided to make a foundation without a film, then a fifteen-centimeter layer of gravel (drainage layer) should be poured onto a layer of sand that should cover the bottom of the trench (cushion).

Then the washed stone goes to work. When laying the first stones, you first need to apply a layer of mortar of 5-8 cm to the bottom of the trench (over gravel or film). The first stones should be laid from the corners, they should be larger and preferably block-like.

With its largest flat side - the bed - the stone is laid on the applied mortar. The existing block-like stone with a suitable angle of 85°-95° ​​is placed in the outer corner of the trench, it becomes the so-called cornerstone. The stone is placed back to back (against) to the wall of the trench. Having laid the cornerstones, it is possible to lay the first large stones along the entire trench, placing them at a distance - right next to one wall of the trench, then to the other - opposite. The voids between the stones must be filled with smaller stones, trying to fit them close to each other. The seams between the stones are filled with mortar grade 100-150. This is how the first row of stones of the future foundation is laid, which should have approximately the same height. Stones, equal in length to the width of the trench, are laid with a poke - across the trench for its entire length. If there are a large number of stones with trench width dimensions, then the first row of the foundation (its sole) is laid with a poke.

Do-it-yourself rubble foundation device (with photo and video)

For the construction of a rubble foundation, stones with a bearing capacity of at least 100 kg / cm2 are used. Laying rubble and other stone is a meaningful process, so when doing one thing (for example, a foundation), you should think in advance about other work that will require a smoother or more beautiful stone.

Such a stone should be immediately taken into a separate pile. These include all stones that have smooth sides, brighter colors or veins in colors, or quartz inclusions, as well as stones with even corners; stones resembling polygons.

When making a foundation from rubble with your own hands, large stones needed for the first row of masonry of the foundation can be thrown into the trench where the trench is not yet covered with foil, and then turned over to the place of laying; or drop them in your arms.

Check out the video of the rubble foundation device to better understand the process technology:

Photos of the rubble foundation are presented below:

Reinforcement for the foundation with rubble stone

After laying the first row of stones, the installation of a reinforcement cage begins, similar to the cage in concrete foundations: the reinforcement is knitted in two layers throughout the entire foundation, overlapping up to 50 cm. At the corners, it is desirable to knit reinforcement bent in an L-shaped manner. The diameter of the reinforcement must be selected depending on the height of the future building. For a one-two-story house, a diameter of 10 mm is sufficient. The fittings are knitted on vertically installed rods. The distance of vertical fittings (racks) from each other should not exceed two meters. If the reinforcement prevents the stonelayer from standing in the trench, then it will need to be knitted in stages: first, laying the trench with stones to the middle, then you will need to tie two new reinforcements to all racks and continue laying the stone almost to the top of the trench. Then the reinforcement is knitted for the last time - the top two reinforcements for all racks. Thus, in general, at least three horizontal rows of two rebars in each are obtained. When viewed from above, every two reinforcing bars of a rubble foundation of any row form a total of two layers - front and rear (or front and rear).

All stones to be laid should be set down with a sledgehammer until they are completely drowned in the solution and abut against the underlying stones. In this case, one should not forget about the rules for dressing stones. That is, if possible, all vertical seams below the laid stones should be covered with overlying stones.

How to make a rubble foundation (foundation from rubble) with your own hands

When laying a rubble foundation with your own hands, you should think in advance about all the communications of a modern house: water and sewer pipes, grounding, alarm and intercom wires, etc. Under all these things, you must immediately leave holes - lay pipes or wooden round timber, which are easily drilled; or plastic eggplants filled with water, also easily removed later. Of the latter, after the foundation has hardened, the water must be drained. Reinforcement of the stone foundation gives it greater strength and reliability. The reinforcement cage can be painted over with primer oil paint. Reinforcement is knitted with millimetric knitting (packing) wire using hook-turns.

Already having an idea how to make a rubble foundation, subsequent rows of stones are laid in a similar way, identical to the construction of walls from stones.

If the basement over the foundation with rubble stone is planned to be made of block stone or brick, then the height of the entire foundation should be the same - in the horizon, which is called the "zero cycle". Then a waterproofing layer in the form of roofing material is placed on the foundation. The second waterproofing layer is placed on the erected plinth. The polyethylene film from the edge of the trench must be brought 5 cm under the roofing material of the first waterproofing layer (cutting off the excess).

Rubble foundation without reinforcement

The laying of a rubble stone foundation can also be done without reinforcement: in this case, the foundation will be less reliable and unstable to seismic effects, but still quite suitable for building a one-story house on it in a seismically hazardous zone. Otherwise, an unreliable foundation leads to the formation of cracks in the walls of the house and its subsequent destruction.

Don't skimp on the foundation! The minimum thickness of the stone foundation should be 50 cm. The finished foundation should be given time to shrink and gain strength. To do this, the foundation is left for the winter, and subsequent work begins in the spring.

Finding the remains of an ancient stone temple for an archaeologist is a great success. Sometimes they dig up buildings about which something is known. For example, the old-timers remember that there used to be a church here, or chronicles clearly point to a specific place.

However, sometimes the remains of the temple are found quite by accident - during exploratory excavations or even just construction work. In this case, most often only the foundation remains of the church, or even less - the foundation ditch. In this case, there is usually no way to find out from external sources what kind of church it was, when it was built, and what church holiday it was dedicated to.

Still, archaeologists can learn a lot about a building by examining it on site. The construction technique in which an architectural monument is made makes it possible to establish the period in which it was built, sometimes with an accuracy of several decades.

In addition, the study of the foundation allows us to make an assumption about the most probable dates for the laying of the temple. And since the church was often founded on the day of the saint or holiday to which it was dedicated, this makes it possible to assume the dedication of the temple, and sometimes even connect the find with written sources.

Task

How can the study of the foundations of an ancient church help to find out the most likely days of its laying?

Clue

The traditions of ancient Russian architecture require that the altar of the temple be turned to the east.

Solution

The laying of the Old Russian church is an important and solemn moment. As far as we can judge, during the laying there were present the highest persons of the spiritual and secular authorities, who were often the customers of the building.

The outstanding historian of architecture Pyotr Alexandrovich Rappoport in his book “Construction production of ancient Rus' (X-XIII centuries) cites two quotations from chronicles and chronicles, separated by almost 10 centuries.

« Then they set one stone as the foundation of the church in the center of the altar, and the remaining unselected stones - at the four corners ... The bishop reads this prayer ... and orders the head of the masters to take a measuring instrument and draw out the area according to the will of the builder I". This is from the Armenian "Foundation of the Holy Church" of the beginning of the 6th century.

« ... His Grace Metropolitan Philip with all the consecrated cathedral ... having gone to the foundation of the church ... And so did ... Grand Duke Ivan Vasilyevich ... And those who performed the prayer service, and above all with his hand, the metropolitan believes the beginning, where the altar be, even in countries and in corners, and according to this, the masters begin the work of the building". This is from the Moscow chronicle of the 15th century.

As we can see, for many centuries, the laying of the Christian church took place in the same way - a stone was laid in the place of the future altar, the contours of the walls and corners of the temple were marked. A plan for future construction appeared on the ground.

As already mentioned in the hint, according to the traditions of ancient Russian architecture, the altar of the temple was supposed to face east. However, in Ancient Rus' there were no compasses, and the east was understood as the place where the sun rises.

But the sun rises exactly in the east only twice a year - on the day of the spring and autumn equinoxes. On other days, the sun rises north or south of the exact east direction. When laying the temple (read - when laying out its plan), the axis of the future building was oriented to the point of sunrise. Thus, by measuring the orientation of the temple using a compass (magnetic azimuth), making a correction for the magnetic declination of the place where the temple is located, it is possible to calculate the angle of declination of the sun and the two days on which the sun rises in this place from the tables. After that, it remains to make an amendment to the ancient Julian calendar (for the X-XI century - 6 days, for the XII century - 7), and archaeologists get two possible dates for laying the temple, and based on the fact that the laying of the first stone usually took place in spring and autumn (so that the construction artel can complete the first cycle of work before the autumn rains - dig foundation ditches, lay the foundation itself and make a brick pavement on top of it) - you can choose one of two dates.

Afterword

A little more than 250 monuments of pre-Mongolian stone architecture are known today. At the same time, less than a fifth of these buildings have survived in one form or another on the surface of the earth. The vast majority of them are churches.

An ancient Russian stone church was everything for a person of that time - a club, a library, a textbook of the Law of God, a fireproof safe (jewels were often stored in the basement floors of churches - after all, only stone churches survived in fires).

The temple means a lot for the researcher of the culture of Ancient Rus'. Any monument of ancient Russian architecture is not only material for an architectural historian. This is both a monument of painting and language (all ancient Russian churches, on which the remains of plaster have been preserved, keep hundreds of graffiti records made by various people). Therefore, it is very important to "squeeze out" all possible information from the monument - and therefore it is so important to be able to at least guess when the temple was founded and to whom it is dedicated.

Of course, the method of determining the date of laying the temple in azimuth has its limitations.

Firstly, it is very difficult to measure the azimuth of the building with an accuracy greater than 1-2 degrees - the plans of the churches themselves were broken with some uncertainty.

Secondly, all calculations are carried out for an ideal horizon, without taking into account the relief, which introduces an additional error.

Thirdly, the date of the foundation of the church does not always coincide with the date of the church holiday to which the temple is dedicated. The study of the chronicles about the construction of the temple suggests that much more often the date of the holiday coincided with the solemn consecration of the church after the construction or even painting of the temple was completed.

Fourthly, sometimes the temple was not oriented to sunrise at all - if the orientation of the temple was influenced by the already existing street buildings or the temple was laid on an older foundation.

Nevertheless, sometimes, even without any chronicle information about the found architectural monument, one can speak with a sufficient degree of confidence about its dedication. First of all, when the azimuth of the building gives out an unusual winter date for the laying of the temple. For example, the Smolensk church at the mouth of the Churilovka River faces the southeast with its altar. Azimuth shows that the temple was founded around February 19, which is very close to the day of Constantine-Cyril (February 14). It is the winter laying that may indicate that the ceremony of laying the temple would certainly be held on the day of the heavenly patron of the church, and the construction itself would begin later, in the spring.

Foundation, as a basis in the construction of a house, they began to build in ancient times. At the same time, the construction process developed. Among the foundations erected in antiquity, an important place was occupied by pile buildings, which were arranged in the mouths of rivers. These buildings were intended to protect against animals and enemies. In the future, the purpose of the piles changed, but they were widely and for a long time used. Buildings built on good foundations are very durable. To this day, some of them have survived and continue to exist. Example: Cheops pyramid. its weight is about 6 million tons, the load on the base is on average 12 kg/cm2.

In ancient times, there were already works on foundation construction, namely: the Roman engineer Vitruvius (first century BC) in his writings gave instructions on the practical construction of foundations. In addition, recommendations for the construction of foundations were also found in the ancient annals of our country. However, all the data of scientists were based only on the basis of the experience of building foundations. However, there was no theoretical basis foundation calculation and grounds. In the 18th century, science made great strides forward in this matter, and the long-awaited theoretical developments in foundation engineering science appeared. The French scientist Coulomb in 1773 developed a theory for calculating the resistance of soils to shear, and a formula for calculating the pressure of soil on a retaining wall. After that, in 1841, the great French scientist Trijot proposed one of the ways erection of coffered foundations. Further in the 19th century, it was opened, which became the main link in the construction of foundations. In 1809, one of the scientists discovered the phenomenon of "electroosmosis". This phenomenon consisted in the fact that water and its particles move in the direction of a negative charge. Subsequently, this phenomenon found its practical application in the bases for the development of pits, where there were water-saturated soils. In addition, our scientists, namely: the Kiev scientist A.E. Straus in 1899 suggested using stuffed piles in construction, which are arranged in drilled wells. The same scientist later proposed to lower the reinforcement into the wells, and then fill them with concrete. One of the first scientific works "Foundations and foundations"was written in 1869. The author of this work was Karlovich, who cited all the known provisions. A rather large contribution was made to the development of the science of foundations and foundations after the end of the October Revolution. In 1929, the sector of foundations and foundations was formed, which was later transformed to the Institute of Foundations and Foundations.

Now let's look at the most accessible ways foundation devices applicable to low-rise residential buildings in ancient times.

Masters in ancient times installed the log house on large stones, and the gaps between them were carefully filled with small pebbles and rubble. After that, they were coated with ordinary clay, which very well insulated the underground or basement from cold and wind. There was one problem, this is the process of ventilation of the subfloor. This circumstance was the cause of increased humidity in the house and rotting of the log house.

For many years and centuries, scientific practitioners in the field of building the foundations of houses have comprehended many, at first glance, insignificant subtleties and important details that remain relevant to this day.

Hello dear readers!

She warned that Montferrand would certainly be remembered: o)

“Buildings placed under the building, and not bringing any immediate benefit, but intended only to take on the entire load of the building and to transfer it to the mainland, are called the foundation of the building.
It consists of two parts:
1. Reinforcing the soles of the building
2. foundation.
Foundation - is the lower part of the structure, extending below the surface of the earth until it meets the earth layer, which is able to resist the pressure exerted by the load of the structure.
The upper surface of the soil in contact with the lower surface of the foundation, the surface along which the pressure of the foundation is transferred to the ground, is called the sole of the building. (Krasovsky A. "Civil architecture. Parts of buildings. 1886)

Since we are talking about how the monument to Alexander II was built at the very end of the 19th century, in order to understand the complexity of the engineering task solved by the architects for the construction of the foundation of the monument, I will cite the previous experience of construction in Russia.

View from our time:

“As a rule, information about the design of foundations and, moreover, about their technical condition, is not available in historical drawings. Architects of past centuries, with rare exceptions, did not depict foundations in the drawings. The appointment of the design, materials, basic dimensions of the foundations was the prerogative of the contractor, who relied on an age-old tradition and his own experience. The quality of the foundations largely depended on the decency of the contractor as a professional. The type of foundation was determined by the mass of the building, the ground conditions of the site, about which there was not always sufficient information, and a set of local materials.

For these reasons, it was technically impossible to provide buildings with a sediment-free foundation until the 60s of the 20th century, since wooden piles could not be longer than 12 m. The example of St. Isaac's Cathedral confirms what was said. It is known that this building, with dimensions in terms of approximately 100x100 m, having a mass of about 3,000,000 kN, was built on a foundation consisting of 24,000 wooden piles and a solid slab of natural stone, buried 5 m into the ground. The costs of this foundation were very high : according to the estimate available in the archive, they amounted to 10% of the costs (2 million rubles in silver). Despite this, the settlement of the building exceeded 1 m, the difference in settlement, expressed in the form of a heel of the floors of the building, reached almost 40 cm.
The wear of underground structures of buildings was also facilitated by factors such as uncontrolled growth of the cultural layer, high groundwater levels and frost heaving forces, vibrations caused by traffic loads, construction, and industry.
For the first 100-120 years since the founding of the city, the foundations of "state" buildings were built with particular care. Wooden piles were driven into the trenches dug under the strip foundations of the bearing walls, on top of which the foundations were laid. This is how the foundations of the walls of the Peter and Paul Fortress, the Peter and Paul Cathedral, the Rostral Columns, the Alexander Column, St. Isaac's Cathedral, and many others were built. Some buildings (for example, the Winter Palace, the New Hermitage) were built on solid slabs…

With regard to St. Isaac's Cathedral, all sorts of fictions with "perplexity" are still being published. Therefore, I give a description of its foundation from the book 1869 year of publication

from which there will be more quotes below: o) https://neb.rf/catalog/00…

Along the way, I will inform everyone who is not yet aware that construction drawings of the early 19th century(that is, the time of the construction of St. Isaac's Cathedral and the construction of the Alexander Column) significantly different from the drawings of our time. Therefore, before declaring that what Montferrand published in his albums are not drawings, I ask you to familiarize yourself with other drawings of the same time. So, before you is a drawing from the book " Practical drawings for the arrangement of the Church of the Presentation of the Blessed Virgin Mary in the Semenovsky Regiment c. St. Petersburg, compiled and executed by the architect, professor of the Academy of Arts ... Konstantin Ton » Ton K.A. 1845

Here you can find out that the foundation was strengthened (compacted) by driving piles, on top of which a rubble grillage was arranged. (remember Isaac). The drawing has a scale bar, a drawing of a copra for driving piles. Compare with the drawing of Montferrand. Alexander Column:

Saint Isaac's Cathedral

Along the way, we can compare the drawings of domes made by Ton

and Montferrand

As you can see, here attention is paid to the foundation and the foundation device. In this book, we also find the same drawings as the drawings of Montferrand. That is, when one of you suddenly wants to declare that there are no drawings for the construction of St. Isaac's Cathedral, remember that first you should get acquainted with what the drawings of the beginning and middle of the 19th century were like, so as not to "see a fig in the book":O))).

Reading the book of adjunct professor Karlovich, one can be convinced that at the end of the 19th century, engineers in Russia gained extensive experience in building structures, developed a methodology for calculating structures, methods for determining the mechanical characteristics of soils and building materials. Therefore, having met the drawing of the foundation of the monument to Alexander II, I realized that it was necessary to write about its construction separately.

The architect of the monument N. Sultanov says:

“In pursuance of the Highest command, from June 20, 1890, the Committee began to arrange temporary structures for the construction of the monument and earthworks at the site of the future foundation. The beginning of earthworks, as we have already said, revealed the presence of the foundations of ancient buildings, as well as the remains of ancient cemeteries. This circumstance immediately made it necessary to replace ordinary earthworks with regular archaeological excavations, which made it possible to acquire many precious remnants of antiquity. Excavations continued throughout the summer of 1890, and the excavation of the earth was carried out to a depth of 2 sazhens, that is, to the sole of the ancient foundations. The area occupied by the excavations was about 60 sazhens long and about 20 sazhens wide, or approximately 1,200 square meters. sazhen…”

A little about the history of the demolition of the Kremlin buildings and orders, the remains of which were found at the site of the construction of the monument to Alexander II.

Bartenev"The Grand Kremlin Palace, palace churches and court cathedrals" https://neb.rf/catalog/00...

In the spring of 1891, earthworks were resumed and continued until August, and were first carried out to the level of the horizon of the lower Kremlin garden, and after a winter break, by the beginning of the spring of 1892, they were brought to a horizon lying 4 arshins below the level of the Kremlin garden, and the mainland was found , quite reliable and suitable for the foundation of the foundation of the side parts. monument. This duration of earthworks was due to the fact that it was necessary to excavate more than 6,500 cubic meters of land. sazhen and lay it on top of the mountain, therefore raising it to a height of 8 sazhens.

The deeper the excavation, the clearer it became that it was necessary to finalize the project of the monument, because " ... it turned out that if you put the monument in the way it is shown on the general plan, presented together with the model for the Highest approval in May 1890, then only the back wall of the monument will stand on good ground, while the middle part (the foundation under the canopy) will stand on only half of it, and the front wall of the monument, closest to the river, will be on alluvial, unsuitable soil, and will require a very deep and complex foundation, which is extremely expensive. All this required the highest approval or permission... «

When the sketches of the statue were ready, the emperor was presented with them for consideration both a modified model and sections of the monument and the ground. The emperor was informed of the difficulties, and having examined everything in detail, he deigned to resolve: “so that all the walls of the monument stand on a good mainland, push it into the depths of the mountain four sazhens, and cut off the resulting excess part of the slope of the mountain and round off the sides” . Thus, the misunderstandings that arose were resolved, and it became possible to proceed with further work. The approved sketch of the statue and the modified model of the monument were kept in the office of the building throughout its construction, and the disassembly of the office was transferred for temporary storage to the Historical Museum.

“The monument to Alexander Ivanovich II, both in terms of its design and in terms of its significant height - thirty-one fathoms from the base of the caisson to the top of the eagle - is a very complex structure. It clearly has three components:
1) Foundation and foundations.
2) The foot of the monument or terrace, and
3) Upper structure, i.e. galleries, entrances and middle canopy.
For greater clarity, we will consider each part separately.
a) Foundation and foundations.
By the end of August 1891, the excavation of the land was brought to the level of the lower Kremlin garden and stopped there. It was impossible to continue further, because, in view of the coming autumn time, it was too late to start the foundations, and, as we have already said, a free flow had to be left for the spring waters. If the bottom of the excavation were lower than the Kremlin Garden, then the spring waters would fill it and loosen the mainland, which could cause a useless deepening of the excavation. In addition, drilling had to be carried out for the final selection of the foundation system.

(quotes from Karlovich's book)

The foundation of the monument could be located in two ways: either by large ledges corresponding to the slope; or on a single horizontal square cutting into the interior of a mountain.
The first device would be much cheaper, the second - incomparably more reliable. In addition, the study of the foundations of open ancient buildings showed the following: all transverse walls perpendicular to the crest of the mountain were torn across, and the longitudinal wall extreme to the crest had a deviation with its upper end outward. All this showed that the components of the mountain could not withstand the load of even relatively low buildings and slid down under their pressure. These observations made it clear as early as the autumn of 1890, that is, immediately after the archaeological excavations, that the compliant position of the foundations was unthinkable and gave the decision to the foremen to excavate the next year to the level of the lower garden, in order to place the foundation of all parts on the same horizon, regardless of the choice grounds.
When the bottom of the excavation was opened in August 1891, it seemed to be quite diverse in its composition: the entire southern part, facing the foot of the mountain slope, consisted of saturated earth, in some places completely black; the other half, facing the inside of the mountain, was mainly yellow sand, and in some places white or red. It was obvious that it became impossible to substantiate the sole of the foundation on this surface, since in this case a good half of the structure would fall on alluvial highly compressible soil. In addition, the heterogeneous composition of the lower surface of the excavation turned into a complete riddle the answer to the most important question: what layers of soil lie below this surface?

The only way to resolve this issue was the production of drilling, which was entrusted, according to the choice of the foremen and the invitation of the Committee, to engineer N.I. Zimin. Boreholes were laid in nine places: four at the corners of the area of ​​the future monument, one in the middle and four at the ends of two mutually perpendicular diameters. Thus, wells No. 1, 2 and 3 fell on the southern side of the monument; No. 4, 5 and 6 along its middle transverse axis and No. 7,8,9 in its northern part. Drilling yielded the following results arranged by wells

All these wells were brought to a level lying below the horizon of the Moscow River by 0.565 sazhens and 7.2 from the upper edge of the excavation. Combined into three profiles, the results of drilling gave a clear picture of the underlying soil layers. In general, as can be seen from Fig. 147-149), they represent the following layering:
1) Below, mountain limestone, almost horizontal in the left profile, uplifted at the northern end in the middle silt and rising at the southern end in the right profile (VII).
2) Above it is a thick layer of white clay with the level of lower, stronger groundwater (VI-V).
3) Above it is a relatively thin layer of red clay (IV).
4) Above all this is a very thick layer of heterogeneous sand with a weaker upper groundwater level (I-III).

The surface of the sand to the left of the middle borehole was horizontal, and to the right of it quickly dropped to the bottom, probably following the former natural slope of the hill towards the river; over this sloping part lay a black bulk layer of earth, apparently formed by historical stratification. Thus, half of the structure was on alluvial soil. In order to avoid this unpleasant historical condition, it was necessary to move it further, into the depths of the mountain, so that the sole of the foundations of its outer walls fell on the sandy mainland, which, as we have already said, was followed by the Highest permission.

(to be continued)