Prestressed shallow foundation
SUBSTANCE: prestressed shallow foundation formed by a foundation slab, a ground base and a support board installed under the foundation slab and under the ground base at the optimal depth. On the foundation slab there are jacks arranged, which are connected with traction rods and with ground anchors, inserted into the support board and stressed with a total force, which is equal to or is slightly higher than the weight of the erected structure. Anchor traction rods are arranged with tubular section to supply mortar during arrangement of a support board.
EFFECT: invention provides for minimisation of ground base deformation and for elimination of bases and foundations of nearly located buildings and structures, reduction of material intensity and labour intensiveness in construction of foundations.
2 cl, 1 dwg
The invention relates to the field of construction, for construction of foundations, arranged under buildings and structures in complex engineering-geological conditions, namely when the weak layers of saturated soils high power conditions existing dense development, but can be used in the construction of buildings and structures on landslide slopes, as well as in transport construction as the Foundation for highways and structures under high dynamic loads.
Known constructive solutions for soil reinforcement (Bigaliev, Vonin, Vdera, Rahmangoolov, SEO and other foundations. Part 2. Fundamentals of Geotechnology. M., Izd-vo DIA, Spbgasu, 2002, str, figure 6.2.).
The reinforcement is made by stacking or piling of reinforcing elements in the subgrade. The reinforcing elements are made of different materials (geotextiles, metal etc). With proper tensile strength and good adhesion to the soil reinforcing elements increase the load bearing capacity of the Foundation.
However, the reinforcing elements are only indirect role valves and are used in exceptional cases, since the device requires more labor and significant material.
Known for design of foundations on the ground is x, sealed static load (Bigaliev, Vonin, Vdera, Rahmangoolov, SEO and other foundations. Part 2. Fundamentals of Geotechnology. M., Izd-vo DIA, Spbgasu, 2002, page 172, RES.).
Static load is created by the device time of the mound on the site of the designed structure, the total weight of the embankment a few more of the weight of the structure, due to which the pore water is squeezed out through a special drain. In soils along with filtration precipitation develop creep skeleton of soil compaction. Analytical and graphical methods to establish intervals of pressure on ground to minimalizatsii subsequent deformations are given in Shu "Some peculiarities of regulation precipitate linear structures constructed on soft soils with creep" (the Mechanics of soil and foundations. Sat. scient. Tr. L., LISI, 1976, No. 12, pp.52-59).
The lack of deep soil compaction and static loads with vertical drainage is the need for large volumes of soil to create mounds and sand for sand drains.
In addition, after removing the temporary vertical load prior to the construction of the onshore facilities possible uneven deformation of the Foundation and Foundation because of backward creep of the soil Foundation.
The closest in technical essence and the achieved result is a pile foundations, which consist of piles of rods and grid - reinforced concrete slabs, distributing forces from the superstructure into separate piles (Bigaliev, Vonin, Vdera, Rahmangoolov, SEO and other foundations. Part 2. M-SPb., str).
Pile foundations are designed to transfer the load to the underlying soil. While pile foundations have been successfully used in construction since ancient times, these designs are not free from material weaknesses.
The disadvantages of a given class of structures, first of all, should include a large consumption of materials and labor, especially since the building currently is often carried out in areas with strong weak layers of soil and deep solid ground.
The main aim of the invention is the design of the Foundation, which would minimize the deformation of the ground during construction and operation of onshore facilities and completely eliminate deformation of the bases and foundations of nearby buildings and structures; developing the design of the Foundation will also help to reduce the complexity and intensity due to the high energy of the Koy of technological design.
The essence of the invention lies in the fact that the Foundation was formed base plate with the attached jacks, which are attached to the upper ends of the ground anchor and the lower ends of the rods of ground anchors sankarani in the base plate, pre-manufactured at the optimal depth in the soil Foundation under the Foundation slab; however, the subgrade prior to the construction of aboveground facilities, may be compressed by means of jacks and ground anchors with a total force equal to or slightly greater weight ground facilities.
To prevent extrusion of part of the soil Foundation of the compressible volume under the foundations of the existing buildings on the perimeter of the base plate on the depth to the base plate is arranged in a wall in the ground.
For grouting with concrete base plate anchor pull made of pipes.
The design of the base is illustrated by drawings, where figure 1 shows the main elements of the proposed design: 1 - base plate; 2 - Jack with lock efforts; 3 - anchor rod; 4 - anchor; 5 - base plate; 6 - soil wall or tongue-and-groove wall; 7 - the subgrade.
In the design position Foundation is established as follows: on the subgrade fit base plate 1 on which is installed yaytsa jacks with stoppers efforts 2; installed thrust anchor 3 anchor 4; run (by the way inkjet technology) support plate 5, while the cement slurry is fed through a thrust anchor 3, made of pipes; after curing of (soil-cement in the base plate 5 along the perimeter of the base plate 1 is arranged wall in trench 6 (option - tongue-and-groove wall); includes 2 jacks, which pull anchor thrust 3 and record the force in the subgrade 7 is subjected to pre-compression (prior to the construction of aboveground facilities).
The force of compression of the soil Foundation should be slightly more weight ground structures, with subsequent plastic deformation of the base during operation of the facility.
Thus, in contrast to previously known designs of foundations, this design will reduce or eliminate the deformation of buildings and structures during construction and during operation due to non-uniform sediment soil Foundation, moreover, using a set of jacks is possible to adjust the position of the base plate.
Due to the fact that under the Foundation slab subgrade is a prestressed reinforced volume, seismic resistance design will be significantly increased.
It should be noted, Thu the proposed design has a high adaptability, since all the elements of a design can be accomplished with the use of modern technologies with minimal effort and relatively low intensity.
1. Pre-stressed shallow foundations formed base plate, ground base and the support plate, located under the Foundation slab and under ground base at the optimal depth, while on the base plate are jacks that are connected with rods and ground anchors embedded in the base plate and tense, with a total force equal to or slightly greater than the weight of the construction, characterized in that the anchoring thrust made tubular section for grouting at the device base plate.
2. Pre-stressed shallow foundations according to claim 1, characterized in that the perimeter of the base plate on the depth to the base plate is arranged in a wall in the ground to prevent extrusion of part of the soil Foundation of the compressible volume.
SUBSTANCE: method to erect a foundation on heaving soils includes installation of a foundation slab and heat insulation material onto a levelled base. A sliding layer is laid on the prepared base, and a multi-layer spatial foundation platform, comprising heat insulation material, is erected in a monolithic manner. The lower reinforced concrete slab is formed with vertical reinforcement rods protruding into crossing ribs along the entire height of the platform. Heat insulation material is laid onto the lower reinforced concrete slab with the possibility to arrange a system of crossing ribs. Crossing ribs are formed. An intermediate reinforced concrete slab is formed, the second layer of heat insulation material is set on it. Cross ribs are formed, and the upper reinforced concrete slab is formed, besides, the vertical reinforcement rods are connected to reinforcement of all slab layers.
EFFECT: reduced labour costs, provision of heat insulation material durability against potential damage, higher spatial stiffness of the foundation slab and its distributing capacity, provision of protection against frost swelling.
3 cl, 1 dwg
SUBSTANCE: heat-insulation foundation comprises wall, foot, insulator of wall, additional insulator of foundation connected to insulators of foot and blind area. Lower edge of foundation insulator is below the level of freezing of soil, and external moistureproof gasket is arranged at the edge of blind area insulator. Additional moistureproof gasket is also located under foot, connected to external moistureproof gasket, and fill is provided between foundation insulator and external moistureproof gasket.
EFFECT: improved operational properties of heat insulation foundation, simplified design, saving of energy resources.
3 cl, 2 dwg
SUBSTANCE: foundation comprises artificial bed with curvilinear surface, bearing elements and shell arranged on bed. Bearing elements are arranged in the form of radial and circular tapes for shells with positive Gauss curvature or transverse and longitudinal tapes for shells with zero Gauss curvature, forming meshy shell and laid through gaskets made of two layers of material, which slide relative to each other, onto concrete surface formed on curvilinear surface of artificial bed arranged in pit and inverted upwards with its convexity. Radial or transverse tapes are fixed by their edges to support contour in the form of support ring or a system of cross beams, which is deepened into natural bed, and gasket of elastic material is located between concrete of shell and support contour.
EFFECT: reduced settling of foundation, lower material intensity, provision of efficient and reliable protection of above-foundation structure.
SUBSTANCE: foundation comprises support part, vertical stiffening ribs installed in it, which form square metal frame, under-column part arranged on vertical stiffening ribs - metal frame and equipped with elements of column structure connection. Support part is equipped with lower and upper reinforcement grids, and stiffening ribs are arranged in the form of at least three beams coming out of a single centre located on vertical axis of foundation, are arranged in the form of bent profiles and equipped with stiffening elements. Stiffening ribs are installed between lower and upper reinforcement grids, and elements of column structure connection to support part are arranged in the form of reinforcement leads.
EFFECT: reduced metal intensity and increased bearing capacity of foundation, simplified design.
2 cl, 4 dwg
SUBSTANCE: monolithic foundation for column erected on natural or manmade basement, for instance rammed in the form of truncated cone, comprises support part with metal frame and under-column part installed on metal frame and equipped with elements of column structure connection. Support part is equipped with lower and upper reinforcement grids, and metal frame is made in the form of rigid inserts, which are symmetrically arranged versus vertical axis of foundation and are installed between lower and upper reinforcement grids. Elements of column structure connection to support part are arranged in the form of reinforcement leads.
EFFECT: simplified design, reduced metal intensity and increased bearing capacity of foundation erected under column.
3 cl, 4 dwg
FIELD: construction industry.
SUBSTANCE: foundation includes natural base with curved surface, load-carrying members and cover located on base. Load-carrying members are made in the form of orthogonal bands forming a meshed cover and laid on system of blocks installed on natural curved base located in ditch and the bulge of which is directed upwards; at that, ends of bands are attached to support outline made in the form of two-way beam system, which is embedded in natural base.
EFFECT: effective and reliable protection of the construction above foundation, reducing material consumption.
SUBSTANCE: method for erection of foundation slab of framed structure includes foundation preparation, arrangement of curb onto prepared foundation, installation of reinforcing grid, its fixation, concreting. Foundation is prepared by filling of gravel layer and a layer of sand over it and laying of hydraulic insulation, for instance PVC film, afterwards lower part of foundation slab of framed structure is shaped by installation of enclosing curb made of concrete, for instance onto hydraulic insulation, arrangement of reinforcing grid limited by enclosing curb along perimetre, fixation of reinforcing grid, for instance by means of welding, transverse and longitudinal axial marking of reinforcing grid into squares, for instance 2.0×2.0 m, in angles of which, perpendicularly to reinforcing grid, reinforcement is installed and fixed, for instance, by means of welding, with length equal to design thickness of foundation slab of framed structure. Concreting of reinforcing grid down to required thickness, with further installation of multiuse curb blocks onto concreted surface in centre of marked squares in number sufficient to fill three first rows perpendicularly to longitudinal axis of foundation slab of framed structure, concreting is performed in two stages, at the first stage space is concreted between enclosing curb, the first and partially second rows of blocks, afterwards concrete should mature to state, when its surface still is adhesive enough for connection with the following portion of concrete to form monolithic structure. At the second stage remaining part of the second and partially third rows of multiuse curb blocks is concreted, after hardness is achieved that excludes concrete breakage, when multiuse curb blocks are withdrawn. The first row of blocks is withdrawn and installed in the fourth row, concreting is continued till final formation of framed structure area. Cells, which are not filled with concrete, produced by blocks of multiuse curb, are closed with reinforced concrete covers, and upper part of foundation slab of framed structure is arranged by laying of reinforcing grid onto produced surface limited along perimetre by enclosing curb, fixation of reinforcing grid, its connection, by means of welding, with outlets of reinforcement of lower part of foundation slab of framed structure and concreting down to required thickness.
EFFECT: reduced material intensity and labour intensity, improved strength and reliability of design.
SUBSTANCE: invention concerns construction, particularly building basements for industrial and civil facilities. Basement includes external shell widening in bottom part and holding filler material of varying material durability grade. Filler material of varying durability is laid in layers in horizontal and vertical directions.
EFFECT: reduced material cost of basement, enhanced reliability.
SUBSTANCE: invention is related to construction, namely to erection of buildings and structures on freezing heaving soils. Foundation on freezing soil includes rigid body comprising foot and wall, with gasket from the side of foot inverted to soil and made of heat insulation material, for instance from foam polystyrene, and also additional heat insulation material installed outside foundation limits. Upper edge of additional heat insulation material is pulled from the side of foundation external edge in the form of broken inserts via rigid body of foundation and is connected to additional heat insulator of opposite external edge of foundation. Pressure on soil in foundation foot is accepted as not higher than value of design resistance of heat insulation material to compression, and relative area of broken inserts (β=Abr ins/A0) is defined from ratio β≤1-σmax/R, where Abr.ins is area of broken inserts section, m2, A0 is gross area of foundation section in place of inserts installation, m2, σmax is maximum tension in foundation material from external loads, MPa, R is design resistance of foundation material, MPa. Additional heat insulation material installed on external side of foundation foot is connected to heat insulation material of foundation external wall. Additional heat insulation material installed on internal side of foundation foot is connected to heat insulation material of foundation internal wall. Inserts of additional heat insulation material of foundation are connected to ceiling heat insulation material above foundation. Heat insulation material installed from external side of foundation wall is connected to heat insulation material of blind area. Heat insulation material installed on internal side of foundation wall is connected to heat insulation material of ceiling above foundation.
EFFECT: provision of possibility to install foundation above design depth of heaving soil freezing, increased level of soil protection under foundation against freezing.
SUBSTANCE: invention relates to foundation construction technologies, and particularly, to reinforcing technology used for compressible foundation sections of detached or standard foundations in buildings and structures being erected under severe engineering and geological and hydro-geological conditions. Method of foundation bed construction by horizontal reinforcing with solid concrete components includes foundation pit mining and installation of horizontal stiff lengthy elements such as crossties. As soon as the foundation pit is developed to the designed depth, which is equal to the sum of foundation bed depth of installation and buffer layer thickness, and is bladed, foundation pit bottom is leveled. After that, foundation axes are broken down and longitudinal axes of future solid crossties are broken down against the established construction layout of the longitudinal axes of future solid crossties regarding foundation axes. The chaps for solid crossties are made mechanically or manually on foundation pit bottom along the marked longitudinal axis of the future solid crossties. Besides, the chap depth is equal to the cross section of the future solid crosstie. The chap bottom is cleaned and reinforced frameworks are laid down in the chaps. The chaps are then cemented together with the reinforced frameworks by means of concrete mix B15 with further compacting. To install horizontal reinforced solid elements in the chaps such as solid crossties are located on the foundation pit level. So, the crosstie distributing element is formed in the compressible section of the built structure foundation bed. In addition, the length of each solid crosstie must not exceed the distance between the external shapes of the utmost foundation edges of the building. The chaps for solid crossties installation are made in parallel to each other and at design distance from each other so that the area of crosstie distributing element overlaps foundations area completely. As soon as the concrete mix in the chaps will achieve the strength no less than 50% from the design strength, the buffer layer is laid down, leveled and compacted. The buffer layer is laid down to the level of built structure foundation bed. The buffer layer consists of sand, crushed stone from solid rocks or crushed stone from ferrous metallurgy wastes. The buffer layer thickness must not be less than 1/3 of solid crosstie width or cross section diameter. The maximum size of crushed stones must not exceed 1/5 solid crosstie width or cross section diameter.
EFFECT: improvement of soft ground foundations bearing capacity and reduction of material consumption.
FIELD: construction, particularly new building erection and existent building reconstruction under any engineering-geological circumstances.
SUBSTANCE: foundation structure comprises shallow foundation and reinforcement members. Reinforcement members are made as vertical bars of precast or cast-in-place piles having diameters less than 200 mm and arranged along foundation perimeter. The piles are spaced a distance from outer foundation faces. The distance is equal to 0.1-0.5 of reinforcement member diameter. Distance between neighboring piles is equal to 2-4 reinforcement member diameters and reinforcement member length is 15-20 diameters thereof.
EFFECT: increased load-bearing capacity due to creating compressive operational conditions under different engineering-geological circumstances, increased dynamic rigidity of foundation base and reduced foundation deformation and vibrational amplitude.
FIELD: building, particularly panel foundations for multistory buildings and structures, which apply non-uniform loads to ground base.
SUBSTANCE: method involves forming crossing slots in ground; reinforcing the slots with frames and concreting the slots. For panel foundation erection in clay ground pit is preliminarily dug in ground. Then crossing slots adapted for reinforcing frames receiving are created in pit ground, wherein the reinforcing frames have projected parts. Areas of reinforcing frames intersection are additionally reinforced along with connecting projected parts and concreting thereof to fill the slots.
EFFECT: increased operational effectiveness and reduced costs.
FIELD: building, particularly to erect bored cast-in-place foundations of increased load-bearing abilities including ones having bottom marks typical to shallow foundations.
SUBSTANCE: stepped foundation comprises bored cast-in-place sections formed with the use of auger. Lower foundation step includes four peripheral cylinders of Dp.l. diameters and heights equal to above diameters. Peripheral cylinder centers are located at apexes of square having side lengths equal to Dp.l.. Square center coincides with center of support. Central support abutting four peripheral cylinders of lower foundation step has four expanded parts with Dc.exp diameters determined as Dc.exp=(1.0-1.2)Dp.l. and cylindrical bore having diameter Dp.up determined as Dp.up=(0.6-0.8)Dp.l.. Foundation bottom is 0.7 m below ground surface. Foundation erection method involves forming drilled pile sections; serially drilling wells having daug.1 diameters as each peripheral cylinder having Dp.l. is forming; creating each peripheral cylinder having height equal to Dp.l. by supplying working material for above cylinder forming; filling remainder well section with ground material, particularly with ground excavated from above object. Auger having diameter, which provides necessary Dp.l. diameter is used. The auger provides usage of technological processes, which provides 1.05-1.1 increase of pile diameter in comparison with auger diameter daug.1 and 1.1-1.2 increase of ground pile diameter in comparison with daug.1 diameter. After four peripheral cylinders of lower foundation step creation well having daug.2 diameter is drilled by means of direct auger rotation and ground excavation to day surface. The well has center coinciding with central support center and depth selected so that the well reach tops pf peripheral lower step cylinders. Then lower expanded part of central support is formed, wherein the expanded part has expansion degree Bc.exp./daug.2 equal to 1.5-2.0. During cylindrical bore drilling the expanded part has expansion degree Dp.up/daug.2 equal to 1.2-1.5.
EFFECT: increased load-bearing capacity per foundation volume unit, extended field of technical means.
3 cl, 4 dwg
FIELD: construction, particularly to erect foundations in natural base.
SUBSTANCE: method involves driving pair of members pivotally connected with each other and provided with single bevels at lower ends thereof in ground; digging-out trench; installing guiding member on trench bottom; forcing plate members in ground up to plate members abutting upon guiding member and closing of beveled upper ends thereof; installing the similar pair of members having lengths exceeding that of the first pair in trench; driving above pair in ground up to upper beveled ends closing; concreting the trench.
EFFECT: increased load-bearing capacity of the foundation due to inclined members embedding and ground compaction under foundation bottom.
FIELD: construction, particularly to erect multistory buildings on non-uniformly compressible clay base.
SUBSTANCE: method involves excavating crossing trenches in ground; filling the trenches with concrete and joining thereof with slab covering the trenches. Trenches are excavated from pit bottom for different depths. Lower trench parts are provided with widened abutment sections having reinforcement bars included therein. The reinforcement bars are used as non-stretched threads. Trenches and slab are reinforced with nettings. Cell centers of the slab are anchored.
EFFECT: increased rigidity of foundation slab due to provision of ribs in ground.
FIELD: construction, particularly to erect foundations on natural bases.
SUBSTANCE: shallow foundation comprises support mats and foundation building blocks. Support mats have through orifices along mat perimeters. Upper parts thereof have extensions shaped as truncated cones and adapted to immerse piles in ground as load increases during structure overbuilding.
EFFECT: increased load-bearing ability.
FIELD: construction, particularly to reconstruct buildings and building structures.
SUBSTANCE: foundation comprises supports, sheath freely formed in ground inside area defined by foundation so that convexity thereof faces upwards and connected to supports by means of flexible ties. Cement mix layer, metal arch trusses and reinforced concrete layer are serially arranged on ground inside area defined by foundation. Metal sheets are laid on arch trusses and connected with each other through welded joints to create flexible sheath. Pre-stressed flexible ties inserted in through support orifices and provided with fixing anchors are placed over the sheath. In the second embodiment foundation comprises support, sheath freely arranged in ground inside area defined by foundation so that convexity thereof faces upwards and connected to supports by means of flexible ties. Ground mix layer reinforced with cement mix, metal sheets and reinforced concrete layer are serially located on ground inside area defined by foundation. Metal sheets are bent along predetermined profile and connected with each other to create sheath. Relaxed flexible ties inserted in through support orifices and provided with fixing anchors are placed over the sheath.
EFFECT: increased operational reliability.
4 cl, 1 dwg, 1 ex
FIELD: construction, surface mounted structures.
SUBSTANCE: invention pertains to construction and can be used when erecting buildings with considerable loading on a compressed clay bed. The technique for erecting a solid core foundation slab with closed vertical walls, directed downwards, involves designing a foundation pit, trenches, reinforcing them with frames and filling with concrete, and joining the surface with a slab. The trenches are dug from the bottom of the foundation with different depths. The trenches are then joined, thereby forming several closed contours, whose depth increases from the central part of the slab to the edges. The technical outcome is increase in strength of the foundation slab due to effect of the square shaped closed edges in the ground.
EFFECT: increased strength of the foundation slab.
FIELD: constructional engineering.
SUBSTANCE: invention refers to constructions on heaving soils. House footing based on freezing through soils includes a rigid body with flanges and indents from soil side, footing indent inserts made of heat-insulating material, e.g. polystyrene foam at such ratio of flange and footing indent areas that soil pressure from the lower flange surface is not less than standard pressure of frost soil heaving, soil pressure from the lower insert surface is not exceeding design compression resistance of insert material. Also, the said footing contains supplementary heat insulation laid outside of the footing. The upper edge of supplementary heat insulation is passed from external edge of the footing in the form of interrupted inserts through rigid body of the footing and connected to supplementary heat insulation of opposite external edge of the footing. Relative area of interrupted inserts (β=Aint.ins./A0) is given by the relation β≤1-σmax/R, where Aint.ins. is sectional area of interrupted inserts, m2, A0 is gross sectional area of the footing within inserts arrangement regions, m2, σmax is maximum external load pressure in footing material, MPa, R is design resistance of footing material, MPa. Indents and flanges of the footing from soil side are alternating along footing length. Indents centres from soil sides are provided under interrupted inserts centres of supplementary heat insulation from each external edge of the footing.
EFFECT: possibility to lay foundation above the design depth of heaving soil frost penetration level.
4 dwg, 1 tbl
SUBSTANCE: invention refers to construction of the basements of buildings. The basement structure of a building includes heat - and waterproofing layer (17, 18, 40) which is laid on a flat horizontal surface (51) layer of the material breaking capillary action. The basement structure includes a frame (31) which surrounds specified heat - and waterproofing layer (17, 18, 40), at least, in its top part, thus fixing integrity of basement structure in a horizontal plane and which serves for punctiform bracing of the building supported by basement structure. The specified basement structure is encapsulated with foil (111) from a metal material.
EFFECT: prevention of smell penetration in a building and water-proofing maintenance; possibility of fast and energy conserving erection of the basement.
8 cl, 8 dwg