Structure for preventing large-area heaped load from generating lateral stress on building foundation

Abstract

The utility model relates to the field of buildings, and discloses a structure for preventing large-area pile loading from generating lateral stress on a building foundation, which comprises a pile foundation consisting of a foundation pile and a bearing platform, a loading surface is arranged on the bearing platform, an isolating layer is arranged between the loading surface and the foundation pile, and the isolating layer comprises an isolating cavity. The isolation cavity is internally provided with filler, and lateral stress borne by the building foundation can be reduced through deformation of the filler. Through the arrangement of the isolating layer, the problem of solving stress measurement through the traditional thinking of resisting is converted into the problem of reducing the stress measurement of large-area pile loading on the pile foundation through the thinking of unloading, so that the pile diameter and the pile number are effectively reduced, the engineering amount is reduced, and the economical efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of building, concretely relates to a structure of blocking lateral stress of building foundation caused by large area stacking. BACKGROUND

[0002] The warehouse of port yard and factory needs to face the problem of large area stacking. When facing the influence of large area stacking on pile foundation, in the design stage, either the pile length and pile diameter are increased to enhance the ability of pile to resist additional settlement and negative friction caused by large area stacking, or a row of cement mixing piles is set as isolation piles between large area stacking and adjacent buildings to effectively reduce the influence of stacking on building pile foundation.

[0003] However, when the original design load is insufficient or new use requirements increase the load, the original design pile foundation cannot meet the requirements, so it is necessary to reform the pile foundation of the building, set isolation piles or carry out foundation treatment, but all have the problems of high cost, great construction difficulty, long construction period and great influence on surrounding environment. UTILITY MODEL CONTENT

[0004] The utility model intends to provide a structure of blocking lateral stress of building foundation caused by large area stacking to reform the existing building and reduce the lateral stress of building foundation caused by large area stacking.

[0005] In order to achieve the above purpose, the utility model adopts the following technical scheme: a structure of blocking lateral stress of building foundation caused by large area stacking, comprising a pile foundation composed of a foundation pile and a pile cap, a loading surface is arranged on the pile cap, an isolation layer is arranged between the loading surface and the foundation pile, the isolation layer comprises an isolation cavity, and the isolation cavity is internally provided with a filler and can reduce the lateral stress of building foundation through deformation of the filler.

[0006] The beneficial effect of the scheme is: according to the theory of elasticity, when a large-area pile is applied on the surface of the soil, the load will generate stress distribution in the soil. The soil will generate compression deformation under the vertical pressure. Since the soil is a continuous medium, the lateral deformation will inevitably occur at the same time as the vertical deformation. Just like when you squeeze a sponge, the sponge will have a tendency to expand horizontally at the same time as being vertically compressed. This expansion tendency will generate horizontal stress in the sponge. The building foundation type with a large-area pile is related to the ground condition below the building. When the bearing stratum of the ground is bedrock, the building foundation usually adopts a shallow foundation, and the influence of the large-area pile on the building foundation is very small and can be ignored. When a factory or warehouse is built on soft soil ground, such as silt and silt soil, the natural ground bearing capacity is low, and the compressibility is high. The large-area pile will generate large settlement and uneven settlement of the soft soil, which may cause problems such as damage of the factory structure and difficulty in stacking of the warehouse goods. When the independent foundation is used under the action of the large-area pile, especially when the horizontal force or eccentric load generated by the pile is large, the independent foundation is prone to instability phenomena such as inclination and sliding. At this time, the pile foundation is used to transmit the load to the deep and solid soil layer or rock layer through the pile body. The main disadvantage of the pile foundation is that the horizontal bearing capacity of the pile foundation is low. In order to resist the horizontal shear force transmitted by the upper structure and the horizontal additional stress transmitted by the large-area pile, a multi-pile pile cap is arranged to jointly resist. The scheme changes the traditional stress measurement problem solved by the thinking of'resistance' into the thinking of 'unloading' to reduce the stress measurement of the pile foundation by the large-area pile, so as to effectively reduce the pile diameter and the number of piles, and further reduce the engineering quantity and improve the economy.

[0007] Further, the filler is medium-coarse sand with a particle size of 0.5-1.0 mm. The sand obtained on the construction site is used as the filler, and the construction is more convenient.

[0008] Further, the depth of the isolation cavity is 0.33-0.55 times the depth of the pile foundation, and the ratio of the width to the depth is 1:10.

[0009] Further, the distance between the isolation cavity and the building foundation pile is 30-50 cm.

[0010] Further, a moisture-proof layer is arranged between the filler and the isolation cavity.

[0011] Further, the moisture-proof layer is made of a flexible moisture-proof material. The moisture-proof layer made of the flexible moisture-proof material can effectively prevent underground water from seeping into the isolation cavity, and maintain the dry state and physical properties of the filler. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 It is a top view of the embodiment of the utility model;

[0013] Figure 2 Fig. 1 is a schematic view of a structure for preventing lateral stress of a building foundation caused by a large-area surcharge, according to an embodiment of the present application; Figure 1 Fig. 2 is an enlarged view of A in Fig. 1;

[0014] Figure 3 Fig. 3 is a sectional view of A-A in Fig. 1. Figure 2 Fig. 4 is a sectional view of B-B in Fig. 1. DETAILED DESCRIPTION

[0015] The present application will be further described in detail by way of specific embodiments as follows:

[0016] The reference signs in the drawings of the specification include: foundation pile 1, surcharge surface 2, isolation layer 3, isolation cavity 31, filler 32, backfill layer 4.

[0017] Embodiment 1

[0018] Embodiment 1 is basically as shown in the accompanying drawings. Figures 1-3 As shown in Fig. 1, a structure for preventing lateral stress of a building foundation caused by a large-area surcharge, according to an embodiment of the present application, comprises a pile foundation composed of foundation piles 1 and a pile cap, the lower ends of the foundation piles 1 of the pile foundation penetrating into a deep hard soil layer, and a surcharge surface 2 being provided on the upper surface of the pile cap, and a backfill layer 4 being provided between the pile cap and the deep hard soil layer. Figures 1-3 As shown in Fig. 2, the surcharge surface 2 is provided with a plurality of isolation cavities 31, and each isolation cavity 31 is filled with a filler 32. Figure 1 As shown in Fig. 3, the isolation cavity 31 is a trench-like structure provided in the backfill layer 4 and perpendicular to the ground, and the trench-like structures are connected to each other to isolate the surcharge surface 2 from the foundation piles 1, and the filler 32 is built in the isolation cavity 31 and can deform to reduce the lateral stress received by the building foundation.

[0019] In this embodiment, the foundation piles 1 are reinforced concrete precast piles, with a diameter of 600 mm and a length of 18 meters, and the pile body concrete strength grade is C30. The foundation piles 1 are arranged in a group pile manner, with a pile spacing of three times the pile diameter, i.e. 1.8 meters. The pile cap is a reinforced concrete cast-in-place structure, with a thickness of 1.2 meters and a concrete strength grade of C35, and the top surface of the pile cap is the surcharge surface 2.

[0020] The isolation layer 3 is provided between the surcharge surface 2 and the foundation piles 1, and the isolation layer 3 comprises the isolation cavities 31, as shown in Figs. 2 and 3. Figure 2 , Figure 3 As shown in Fig. 3, the isolation cavity 31 is a trench-like structure provided in the backfill layer 4 and perpendicular to the ground, and the trench-like structures are connected to each other to isolate the surcharge surface 2 from the foundation piles 1, and the filler 32 is built in the isolation cavity 31 and can deform to reduce the lateral stress received by the building foundation. The depth of the isolation cavity 31 is 0.33-0.55 times the depth of the pile foundation. In this embodiment, the depth of the pile foundation is 18 meters, and the depth of the isolation cavity 31 is selected to be 0.45 times the depth of the pile foundation, i.e. 8.1 meters. The ratio of the width to the depth of the isolation cavity 31 is 1:10. According to the depth of the isolation cavity 31 of 8.1 meters, the width of the isolation cavity 31 is calculated to be 0.81 meters. The distance between the isolation cavity 31 and the building foundation piles 1 is 30-50 cm. In this embodiment, the distance m between the isolation cavity 31 and the building foundation piles 1 is set to be 40 cm, which can ensure the isolation effect and will not affect the stability of the foundation piles 1.

[0021] The filler 32 is medium-coarse sand with a particle size of 0.5-1.0 mm. In this embodiment, medium-coarse sand with a particle size of 0.75 mm is selected as filler 32. The relative density of the medium-coarse sand is controlled between 0.4 and 0.5 to maintain a loose state, thereby ensuring that it has good deformation capacity and stress buffering effect.

[0022] A moisture-proof layer is provided between the filler 32 and the isolation cavity 31. The moisture-proof layer is made of a flexible moisture-proof material. In this embodiment, the moisture-proof layer is made of 1.8mm thick HDPE geomembrane, which has good flexibility and waterproof performance. The moisture-proof layer is fully laid on the inner wall of the isolation cavity 31, extending 30cm above the ground and connecting with the ground waterproof layer to form a complete waterproof system, effectively preventing groundwater from seeping into the isolation cavity 31.

[0023] When a large area of ​​surcharge generates lateral stress, this stress first acts on the isolation layer 3. Because the medium-coarse sand filling material 32 in the isolation layer 3 has a large deformation coefficient, it can absorb part of the stress energy through the relative displacement between particles, and at the same time cut off the stress transmission path, thereby significantly reducing the lateral stress transmitted to the foundation piles 1 and protecting the safety of the building foundation.

[0024] Example 2

[0025] Example 2 is basically the same as Example 1, except that during construction, the isolation cavity 31 is supported by steel sheet piles with a thickness of 10mm. After the isolation cavity 31 is filled, the steel sheet piles are retained as the permanent support structure of the isolation cavity 31. At the same time, the support steel plate can also uniformly transfer the lateral stress to the fine sand filling the isolation cavity 31. Through the deformation of the fine sand, part of the lateral stress is absorbed, thereby further reducing the impact of lateral stress on the foundation pile 1.

[0026] The above descriptions are merely embodiments of this utility model. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that the technical means used to solve problems in the above embodiments of this utility model can be combined to solve multiple technical problems simultaneously. For those skilled in the art, several modifications and improvements can be made without departing from the technical solution of this utility model, and these should also be considered within the scope of protection of this utility model. These modifications will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A structure for preventing lateral stress on a building foundation caused by large-area surcharge, comprising a pile foundation consisting of foundation piles and a pile cap, wherein a loading surface is provided on the pile cap, characterized in that: The isolation layer is arranged between the loading surface and the foundation pile, and the isolation layer comprises an isolation cavity, and the isolation cavity is internally provided with a filler and can reduce the lateral stress received by the building foundation through deformation of the filler.

2. A structure to resist lateral stress on a building foundation from a large area surcharge according to claim 1, wherein: The filler is medium-coarse sand with a particle size of 0.5-1.0 mm.

3. A structure to resist lateral stress on a building foundation from a large area surcharge according to claim 2, wherein: The depth of the isolation cavity is 0.33-0.55 times the depth of the pile foundation, and the ratio of the width to the depth is 1:

10.

4. A structure to resist lateral stress on a building foundation from a large area surcharge according to claim 3, wherein: The distance between the isolation cavity and the building foundation pile is 30-50 cm.

5. A structure to resist lateral stress on a building foundation from a large area surcharge according to claim 4, wherein: A moisture-proof layer is arranged between the filler and the isolation cavity.

6. A structure to resist lateral stress on a building foundation from a large area surcharge according to claim 5, wherein: The moisture-proof layer is made of flexible moisture-proof material.

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