Reinforced concrete slab to erect non-submerged foundations
SUBSTANCE: reinforced concrete board to erect non-submerged foundations is formed with a flat reinforced concrete structure. A flat reinforced concrete structure of a slab is made in the form of two beams crossing at the angle of 90°, and in the place of connection of beams there are curvilinear side vertical surfaces with radius of curvature, equal to 1.5 of beam width. The length of the beam is four times more than its width, at the same time the width of the beam is determined in accordance with the area of the pillar base.
EFFECT: reduced contact stresses in a system of foundation slab-soil base, reduced material intensity and labour intensiveness.
2 cl, 2 dwg
The invention relates to the field of construction, and more specifically to structures nezaposlenih foundations and structures precast slabs.
Currently, in terms of the existing dense built-up areas of cities, located on the banks of various reservoirs, new construction requires new technical solutions, in particular, otepka trenches for shallow foundations is not only time consuming but also is a threat for existing in the immediate vicinity of buildings and structures, because ground Foundation on such territories vodonayeva, and the groundwater level is high enough.
The installation of pile foundations under such conditions is very time consuming, in addition, the thickness of the layers is weak saturated soils is 10-20 metres, which leads to increased risk for existing buildings in the operations.
In connection with the above, there is a need to develop new technical solutions in the field of Foundation and, in particular, nezaposlenih foundations, as well as methods of their construction and the development of individual components and parts of such foundations.
Known base plate under columns and walls . Base plate can be arranged under the column, under the walls or under the grid columns, and the columns with redbalcony.
These design base plates are applied to the device for foundations under a single column, and a grid of columns and walls.
Design of rectangular plates well developed, and their technology of concrete on construction sites can be mechanized.
Such plates are bending in two perpendicular directions.
However, rectangular plate causes an increased flow of concrete as zone plates in the corners along the diagonals of the rectangle are the stress concentration zones of the plate when working on the curve and the marginal status of such plate is characterized by the formation of linear plastic hinges in these areas  , moreover, the corners of the plates are areas of stress concentration in the soil Foundation.
Thus, a rectangular shape for the base plates is not rational and in addition solid rectangular base plate to grid columns are extremely uneconomical, as shall be calculated to significant bending moments arising in the plate due to the heterogeneity of the soil Foundation.
It should also be noted that a rectangular base plate, usually in concrete at the construction site, resulting plates are made of concrete and natural torden the I and during operation may experience not only elastic deformation, but the increased plastic deformation under load, which in combination with the plastic deformations of the soil Foundation can lead to uneven and trudnoprohodimi deformations of the building as a whole.
Also known construction prestressed shallow foundations , which can be attributed to nezaposljena foundations and which formed the 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 weight of the construction, and along 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 the soil Foundation of the compressible volume.
This design of the Foundation can be built without atapci of the pit, and, in addition, due to the fact that when the Foundation slab subgrade pressed with a force equal to the weight of the building erected, any uneven settling of the Foundation in the process of building operation will not occur.
However, the proposed design the Foundation is a fairly complex structure, which will require large expenditures during the construction and in the production of works on creation of pre-tension in the system the subgrade - base plate".
In addition, the application of the foundations of this type in terms heaving of soil is hardly possible without additional enhancements constructive solutions.
The closest technical solution to the claimed invention is the construction of circular and annular base plates shallow .
The foundations of the specified design rational in its form, that ensures a uniform distribution of the contact stresses on the contour of the plate when it is loading, the technology of their devices are well designed and are currently widely used in construction practice, theory and calculation of stress-strain state in the "round base plate - the subgrade" is sufficiently well developed .
However, it should be noted that the disadvantage of the considered plate design is that it can be applied only for the perception of single concentrated loads (single columns, chimneys and exhaust pipes and so on), the connection plates of this design for the bearing under the column grid is not possible due to in the build-up of concentration of local stresses around the edge of the plate.
In addition, the production of all slabs impossible using hydrothermal heat treatment at elevated parameters that would cause significant not only elastic, but also plastic deformation of the plates during operation.
Thus, at the present time there is no satisfactory design of reinforced concrete slabs, providing savings of materials and allowing to arrange nezaposljena foundations for unit loads, and for a grid of columns, walls and endblock.
The main task, which is aimed invention is to save material, reduce the effort required for the production of plates, and when the device nezaposlenih foundations for unit loads, as well as for grids, columns, walls and endblock.
It is also necessary to expand the technological capabilities in the manufacture of plates, particularly plates can be manufactured at high parameters of heat treatment of concrete is minimized by plastic deformation.
In accordance with the task has developed a new design of flexible reinforced concrete Foundation slab.
This object is achieved with the help of the proposed concrete slab for the construction of nezaposlenih foundations, which, like the prototype, is formed flat W the concrete structure.
Unlike the prototype flat reinforced concrete slabs made in the form of two intersecting under an angle of 90° beams, and at the junction of the beams is made of a curved vertical side surface with a radius of curvature approximately 1.5 times the width of the beam, and the beam length four times its width, the width of the beam is determined in accordance with the area of the base of the column.
At the ends of beams, plates installed poluchenii to connect the plates in the base system formed of multiple plates.
The essence of the invention lies in the fact that due to the implementation of concrete slabs in the form of rational cruciform shape reduces contact stresses in the system base plate - the subgrade, and also can be reduced. In addition, the proposed base plate can be manufactured in the factory, which reduces the level of plastic strain in the concrete.
In addition, the implementation of flat concrete plate design in the form of two intersecting under an angle of 90° beams, and at the junction of the execution of beams with curved lateral vertical surfaces with radius of curvature equal to 1.5 the width of the beam made it possible to increase the moment of resistance of the beam in accordance with ibiosim moment, and thus, the beams are beams of equal resistance .
The invention is illustrated by drawings, where Fig.1 shows a reinforced concrete slab for the construction of nezaposlenih foundations in the plan, Fig.2 shows plate, side view.
Concrete slab for the construction of nezaposlenih foundations consists of beams 1 and 2, intersecting with each other at the ends of beams installed hinges 3.
Concrete slab has a length of beam L and the width of the Century At the junction of the beams is made of a curved vertical side surface with radius of curvature R equal to 1.5 the width of the beam C. In Fig.2 shows a side view of a plate with thickness t.
The value of L=4V, size, t is calculated in accordance with the loads from the installed structures. The radius R determines the configuration of the plate, which reduces the contact stresses in the system base plate - the subgrade". At the ends of beams installed poluchenii for connection of boards in a single system, which can form neselovskyi the Foundation for the grid columns.
The design of the plate beams cross at an angle of 90°, the thickness of the beams t, and accordingly, the thickness of the plates are determined by the strength calculation, the width of the beams is determined in accordance with the dimensions of the supporting pad mounted on the plate of the building structure.
In C the order to reduce the contact stresses in the system base plate - the subgrade places of connection beams are in a plane with curvilinear lateral vertical surfaces with radius of curvature R equal to 1.5 the width of the beam Century
The work of the proposed concrete slab for the construction of nezaposlenih foundations as follows: for the bearing under the grid columns at the ends of beams installed poluchenii, a connecting plate in a single base system, with some unevenness of the soil Foundation system bearing will not cause additional bending moments and shear transfer only and shifting efforts.
With a substantial excess of the design load on the plate in the bearing system it is possible to produce a local gain at the expense of grading and compaction of the soil surface or through the use of piles to distribute gravel cushion arranged between the pile top and the bottom surface of the plate.
Due to the fact that the proposed concrete slab for the construction of nezaposlenih foundations can have a small size, as the system of support under the grid columns can be constructed from separate plates and is not required to concrete continuous slab, it is possible to produce plates of the proposed design in the factory using heat treatment value when the parameters or with the use of vibro-impact technologies in forming plate, which will greatly reduce the plastic deformation of the plate during operation under sustained loading.
Thus, the advantage of the proposed plate design is rational form, in the form of cross-beams of variable rigidity equal resistance, which reduces the contact stresses in the system base plate - the subgrade".
In addition, the plate can be used for single loads, and system support under the column grid by connecting the individual plates in a single system using polychroniou installed on the ends of the beams.
Due to the relatively small dimensions of the slab can be manufactured industrially using progressive technology that allows you to reduce plastic deformation of the plate under prolonged loading.
Sources of information
1. B. I. Dalmatov and other Bases and foundations, part 2, Moscow-St.-Petersburg, 2002, S. 62, Fig.3.1, Fig.3.2.
2. N. With. Karpukhin. Reinforced concrete structures, S. 339, GOS. Ed. on construction and architecture, M., 1957
3. Russian Federation patent No. 2464381, IPC: E02D 27/01, 20.10.2012,
4. L. A. Boxes, and other Flue and vent pipes as spatial structures, Moscow, 2006, SS.68, 69, 70, 155 C., the prototype.
5. K. E. Egorov. To calculate deformations of foundations, Proceedings from ATA, Institute of foundations and underground structures to them. N. M. Gurianova, Moscow, 2002
6. N. M. Belyaev. Strength of materials. M: State. Ed. technology.-theory. literature, 1951, SS.388-389.
1. Concrete slab for the construction of nezaposlenih foundations formed flat reinforced concrete structure, characterized in that the flat reinforced concrete slabs made in the form of two intersecting under an angle of 90° beams, and at the junction of the beams is made of a curved vertical side surface with a radius of curvature approximately 1.5 times the width of the beam, and the beam length four times its width, the width of the beam is determined in accordance with the area of the base of the column.
2. Concrete slab for the construction of nezaposlenih foundations under item 1, characterized in that the ends of beams slabs installed hinges for connecting the plates to the Foundation system formed of multiple plates.
SUBSTANCE: invention relates to the construction of shallow foundations. Slab foundation, reinforced with recessed cage located outside the foundation along its perimeter at some distance from the edge of the plate. Deepening of the bottom of the cage exceeds the depth of maximum horizontal ground motions. The distance between the cage and the edge of the slab is set according to the planned design bearing capacity or settlement of the foundation and in the composite cage made of reinforced components their upper parts are connected by a belt.
EFFECT: technical result is the increase of the reliability and load-bearing capacity of the slab foundation, reduction of its settlement, reduction of material consumption.
8 cl, 9 dwg
SUBSTANCE: monolithic system of a base with a resistant composite coating from homopolymer having semi-continuous configuration comprises load-distributing elements for formation of seams. Comprises a base that includes blocks from polystyrene foam and a bearing semi-continuous cement-concrete coating, the formwork for which is formed by blocks from polystyrene foam that are part of the base. Load-distributing elements are made in the form of load-distributing plates. Each of load-distributing plates comprises two anchors with two reinforcement bars for setting the position of the seam shaper and a hinged joint made as capable of counterclockwise rotation under action of a support moment, developed by the load, and clockwise rotation under action of the support moment developed by load-distributing plates.
EFFECT: efficient operation of a base under action of various loads, reduced material intensity and labour intensiveness.
6 cl, 6 dwg
SUBSTANCE: combined frame-raft foundation for low height construction on soft soil includes a girder reinforced concrete foundation under all bearing walls of the building from factory-built slabs joined to each other and combined into a system of cross bands laid onto a levelled base on the hydraulic insulation layer in the form of a film under the entire building, each of the slabs is made with a section of closed shape with an insulant arranged inside, and the space between the slabs of the frame is filled with earth mass and a layer of the insulant on top, forming the bearing structure of the first floor slab. Slabs of the girder reinforced concrete foundation under all bearing walls are made in the form of a shell of trapezoid rigid shape of section of spatial and closed type, formed from upper and lower slabs of the spatial type, connected to each other. The lower slab is arranged as wider than the upper one and is equipped with boards along the length. The upper slab is made with inclined ribs. In the boards and in the lower part of inclined ribs there are slots, where bushing keys are embedded, with the help of which the upper and lower slabs are connected to each other, and in the places of joints the slabs are equipped with reinforcement protrusions for joining with reinforcement of adjacent elements with node embedding.
EFFECT: increased efficiency of a frame raft foundation due to increased rigidity, improved thermal protection properties, reduced material intensity and labour costs in manufacturing, provision of operation reliability.
2 cl, 3 dwg
SUBSTANCE: basement comprises a natural or an artificial base with a curvilinear cylindrical surface, a membrane laid onto the base and a support contour in the form of a system of cross beams. The membrane is laid via gaskets made of two layers of the material sliding relative to each other, onto the curvilinear cylindrical surface of the natural or artificial base arranged in a pit and turned upwards with a convexity. In the transverse direction the membrane is attached by edges to the support contour in the form of a system of cross beams, which is submerged into the natural base.
EFFECT: reduced subsidence of a basement, higher reliability of a structure above the basement, creation of an efficient membrane basement, reduced material intensity.
SUBSTANCE: method for construction of a foundation includes preparation of a pit bottom for a foot, production of its rigid filler and an external shell of truncated cone shape with expansion of the lower part of its wall and formation of a compacted soil core. The foundation is erected from structural and soil construction elements. The bottom of the pit is prepared for the foot of the structural element with a groove in soil with the specified geometric shape, its rigid filler is made in a sectional conical form from fractions of lumpy clay and cement-sand mortar with the foot of the specified geometric shape. Expansion of the lower part of the wall in the external monolithic reinforced concrete shell is carried out with a foot with the specified geometric shape as well. A soil construction element is formed under a foot of a structural element with a rated pushing load from a structure, as a rigidly coupled compacted core in the form of a circular cone.
EFFECT: improved quality, reliability, bearing capacity of a base, performance, provision of foundation interaction with a base.
8 cl, 2 dwg
SUBSTANCE: lock prefabricated strip footing includes a support slab and rows of foundation slabs arranged on it. The support slab has a face inclined and bonder surfaces, the upper rib for a slot fixation into a lock of the above block. Foundation units have vertical and horizontal slots, protruding beyond faces of the bed and outbond surface by 1/3 of the width, at the same time the last row of the strip footing is arranged from a block, having a flat upper horizontal surface for resting of wall materials when erecting above walls.
EFFECT: reduced labour intensiveness of foundation blocks assembly, increased accuracy of foundation blocks installation, reduced deviations from horizontal and vertical planes, higher resistance of foundation blocks to displacement due to application of geometric parameters of a foundation block.
5 cl, 1 ex, 6 dwg
SUBSTANCE: foundation includes boards arranged on a levelling sand preparatory base, having limiters under a foot. Boards have through slots along edges, and limiters are arranged in the form of flat plates, as capable of their insertion into through slots.
EFFECT: increased rated resistance of base soil, increased bearing capacity and reduced subsidence of a structure.
3 cl, 3 dwg
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
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
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