Section steel plate cement-soil stirring wall structure for deep foundation pit

Abstract

The utility model discloses a structural steel plate cement soil stirring wall structure for a deep foundation pit. The structural steel plate cement soil stirring wall structure comprises a three-axis cement soil stirring wall, H-shaped steel and U-shaped steel plate piles. Wherein the three-axis cement soil stirring wall is of a three-circle lap joint pile body structure, and the H-shaped steel and the U-shaped steel sheet piles are arranged in the three-axis cement soil stirring wall. A plurality of profile steels and a plurality of U-shaped steel sheet piles are uniformly distributed in the three-axis cement-soil stirring wall; convex spigots are arranged on the H-shaped steel, concave spigots are arranged on the U-shaped steel sheet piles, and the H-shaped steel and the U-shaped steel sheet piles are connected through the convex spigots and the concave spigots to form a continuous steel sheet pile combination. According to the U-shaped steel sheet pile, the concave spigots are meshed with the convex spigots of the H-shaped steel, so that the problem that the local shear bearing capacity of a traditional SMW construction method pile cannot be calculated completely due to the fact that the strength of cement soil is too low is solved, and meanwhile the problem that the cement soil between the steel sections is extruded out due to the pressure effect of water and soil on the outer side is solved.

Description

Technical Field

[0001] The utility model belongs to the field of deep foundation pit support, and particularly relates to a steel plate cement-soil mixing wall structure for deep foundation pits. Background Technique

[0002] As a support structure form for foundation pit engineering, the steel-plate cement-soil mixing wall is an engineering technology introduced from Japan in the 1990s of last century (SMW method) and digested, absorbed and re-innovated in combination with the actual situation in China. In the past three decades, more and more regions in China have begun to adopt this technology. This method uses cement as the main curing agent, and the curing agent and foundation soil are forcibly stirred by a triple-axis mixer, and then steel sections are inserted into the pile body. After the pile body hardens, a continuous, impermeable and certain-strength pile body is formed.

[0003] When using this method as a support structure, in addition to the requirement that the inserted steel sections need to meet the corresponding bending and shear resistance requirements, the cement-soil between the steel sections also needs to meet the requirement of local shear bearing capacity, and the local shear bearing capacity is proportional to the standard value of the shear strength of the cement-soil. According to the test results of many projects using this method, due to the influence of factors such as soil layer conditions, excavation depth and construction technology, the local shear bearing capacity of the cement-soil is insufficient and difficult to reach the design requirement value, the impermeability effect is poor, and the strength is low and it is easy to be extruded and cause problems such as water gushing and sand gushing at the pile intervals. This undoubtedly greatly limits the application scope of this method. Summary of the Invention

[0004] In order to solve the above technical defects in the prior art, the utility model provides a steel plate cement-soil mixing wall structure for deep foundation pits, which can not only avoid the problem that the local shear bearing capacity of the cement-soil cannot pass the check, but also significantly improve the impermeability of the retaining structure, and greatly improve the application scope of this method on the premise that the steel sections meet the bending and shear resistance requirements, so as to provide a choice for the application in deeper foundation pit projects and save the project cost.

[0005] The technical solution for realizing the purpose of the utility model is as follows:

[0006] A steel plate cement-soil mixing wall structure for deep foundation pits, comprising a triple-axis cement-soil mixing wall, H-shaped steel sections, and U-shaped steel sheet piles;

[0007] The triple-axis cement-soil mixing wall is a three-circle overlapping pile body structure, and the H-shaped steel sections and U-shaped steel sheet piles are arranged in the triple-axis cement-soil mixing wall.

[0008] Furthermore, there are multiple H-shaped steel sections and U-shaped steel sheet piles, which are evenly arranged in the triple-axis cement-soil mixing wall;

[0009] The H-shaped steel is provided with a convex stopper, and the U-shaped steel sheet pile is provided with a concave stopper. The H-shaped steel and the U-shaped steel sheet pile are connected by the convex stopper and the concave stopper to form a continuous steel sheet pile combination.

[0010] Furthermore, the convex stop is a φ36 round steel, which is arranged at both ends of the flange plate on the soil-facing side of the H-shaped steel, and the center of the circle is arranged on the center line of the flange plate.

[0011] Furthermore, the size of the concave stop of the U-shaped steel sheet pile corresponds to the size of the convex stop.

[0012] Furthermore, a waterproof sealant is provided on the convex stop.

[0013] Furthermore, the waterproof sealant 7 is a silane-modified polymer waterproof sealant.

[0014] Compared with the prior art, the present invention has the following significant advantages:

[0015] (1) The support structure of the utility model is simple, easy to construct, low in cost, and has good waterproofing effect. It can well solve the problem that the application scope of the traditional SMW construction method pile is limited due to the low strength of cement soil. It can also solve the problem that the waterproofing of the HUW construction method is difficult and the fertilizer tank needs to be backfilled.

[0016] (2) The U-shaped steel sheet pile of the utility model is meshed with the convex stop of the H-shaped steel through the concave stop, thereby avoiding the problem of the traditional SMW construction method pile failing to pass the local shear bearing capacity calculation due to the low strength of the cement soil. It also avoids the problem of the cement soil between the steel sections being squeezed out due to the external water and soil pressure.

[0017] (3) The U-shaped steel sheet piles of the utility model structure are meshed with the convex stop of the H-shaped steel to form a continuous impermeable wall. In addition, the water-isolating effect of the cement-soil mixing wall forms a multiple water-isolating curtain, which greatly reduces the risk of leakage in the foundation pit. In addition, the rigidity of the U-shaped steel sheet piles is relatively small, and their contribution to bending and shear resistance can be ignored in the calculation. The strength, deformation and stability of the foundation pit are verified according to the SMW method, which has a certain safety margin.

[0018] (4) In the U-shaped steel sheet pile and H-shaped steel locking joint of the utility model structure, silane-modified polymer water-stop sealant is applied on site on both sides of the convex stop at the end of the steel flange. After the steel sheet pile is inserted, the trace water leakage caused by the gap between the steel section and the steel plate can be blocked.

[0019] The present invention will be described in further detail below with reference to the accompanying drawings and specific implementations. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1Schematic diagram of the steel section steel - steel sheet pile cement - soil mixing wall for deep foundation pits of the present utility model.

[0021] Figure 2 Schematic diagram of the H - shaped steel structure of the present utility model.

[0022] Figure 3 Schematic diagram of the U - shaped steel sheet pile structure used in the present utility model Figure 1 。

[0023] Figure 4 Schematic diagram of the U - shaped steel sheet pile structure used in the present utility model Figure 2 。

[0024] Figure 5 Schematic diagram of the U - shaped steel sheet pile structure used in the present utility model Figure 3 。

[0025] Figure 6 Schematic diagram of the connection between the H - shaped steel and the U - shaped steel sheet pile of the present utility model. Specific implementation manners

[0026] It is easy to understand that according to the technical solution of the present utility model, without changing the essence of the present utility model, those of ordinary skill in the art can conceive of various implementation manners of the present utility model. Therefore, the following specific implementation manners and the drawings are only illustrative descriptions of the technical solution of the present invention, and should not be regarded as all of the present utility model or as a limitation or restriction on the technical solution of the present utility model. On the contrary, the purpose of providing these embodiments is to enable those skilled in the art to understand the present utility model more thoroughly. The preferred embodiments of the present utility model will be specifically described below with reference to the drawings, where the drawings form a part of this application and are used together with the embodiments of the present utility model to illustrate the innovative concept of the present invention.

[0027] Embodiment

[0028] Combined with Figure 1 , a steel section steel - steel sheet pile cement - soil mixing wall structure for deep foundation pits includes a three - axis cement - soil mixing wall 1, H - shaped steel 2, and U - shaped steel sheet piles 3;

[0029] The three - axis cement - soil mixing wall 1 is constructed by a three - axis mixing pile machine. This wall forms a pile body structure with three circles overlapping each other by forcibly mixing cement and soil, and forms a wall through continuous construction by the socket - in - one - hole method. The H - shaped steel 2 and U - shaped steel sheet piles 3 are arranged inside the three - axis cement - soil mixing wall 1.

[0030] Both the H - shaped steel 2 and the U - shaped steel sheet piles 3 are multiple and are evenly distributed inside the three - axis cement - soil mixing wall 1;

[0031] Combined with Figure 2A convex stop 6 is provided on the H-shaped steel 2, and a concave stop is provided on the U-shaped steel sheet pile 3. The H-shaped steel 2 and the U-shaped steel sheet pile 3 are connected by the convex stop and the concave stop to form a continuous steel sheet pile combination.

[0032] The convex stop 6 is made of φ36 round steel and is welded to the ends of the flange plate on the outer side of the H-shaped steel 2 facing the soil. The center of the circle is set on the center line of the flange plate. The various sizes of H-shaped steel 2 shown in this embodiment are as follows: Figures 3 to 5 As shown, they are models such as U264x10, U864x12, and U552.6x10, which can be used in close-packed, every other plug-in, every other plug-in, and corner locations.

[0033] The size of the concave stop of the U-shaped steel sheet pile 3 corresponds to the size of the convex stop 6. The H-shaped steel 2, U-shaped steel sheet pile 3 and the triaxial cement soil mixing wall 1 form a continuous steel sheet pile combination system through the engagement of the concave and convex stops. In this embodiment, the H-shaped steel 2 with convex stops can be combined to form a close-fitting arrangement with a spacing of 600mm, an H-shaped steel 2 with a convex stop inserted every other one with a spacing of 1200mm, and an H-shaped steel 2 with a convex stop inserted every other one with a spacing of 600 / 1200mm. All U-shaped steel sheet piles 3 with concave stops need to be connected to adjacent H-shaped steels 2 with convex stops to form a continuous wall.

[0034] A waterproof sealant 7 is provided on the convex stop 6, which adopts a silane-modified polymer waterproof sealant. After the material is wet-cured, it not only has excellent weather resistance, water resistance, aging resistance and durability, thereby ensuring the waterproof performance of the lock mouth, but also can block the trace water leakage caused by the gap between the steel sections and steel plates.

[0035] During the specific implementation, a three-axis mixing pile machine is first used to construct a three-axis cement-soil mixing wall 1. The wall is formed by forcibly mixing cement and soil to form three circular piles that overlap each other, and the wall is formed by continuous construction through the sleeve-hole method; then, φ36 round steel 6 is welded to the two ends of the outer soil-facing flange of the H-shaped steel, and its center is located on the center line of the flange plate to form an H-shaped steel 2 with a convex stop, and a silane-modified polymer waterproof sealant 7 is applied to the surface of the φ36 round steel 6 to form a lock waterproof of the combined steel sheet pile; the H-shaped steel 2 with a convex stop is inserted into the three-axis cement-soil mixing wall at a certain interval using a steel positioning device to form a steel-cement-soil mixing wall; finally, the U-shaped steel sheet pile 3 with a concave stop is inserted between adjacent H-shaped steels 2 with convex stops to form a steel-steel plate cement-soil mixing wall.

[0036] The structure of the utility model can well solve the problem that the application range of the traditional SMW method pile is limited due to the low strength of the cement soil, and can also solve the problems of difficult external waterproof construction of the HUW method and the need for backfilling of the fat groove. The U-shaped steel sheet pile in the structure is engaged with the convex stop of the H-shaped steel through the concave stop, avoiding the problem that the local shear bearing capacity calculation of the traditional SMW method pile fails due to the too low strength of the cement soil, and at the same time avoiding the problem that the cement soil between the steel sections is extruded due to the action of the external water and soil pressure. The structure is simple, the construction is convenient, the cost is low, and the waterproof effect is good.

[0037] The above embodiments show and describe the basic principles and main features of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the utility model. Without departing from the spirit and scope of the present invention, the utility model will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A steel sheet pile cement-soil mixing wall structure for deep foundation pits, characterized in that It includes a three-axis cement-soil mixing wall (1), H-shaped steel (2), and U-shaped steel sheet piles (3); The three-axis cement-soil mixing wall (1) is a three-circle overlapping pile structure, and the H-shaped steel (2) and U-shaped steel sheet piles (3) are arranged inside the three-axis cement-soil mixing wall (1).

2. The steel sheet pile cement-soil mixing wall structure for deep foundation pits according to claim 1, characterized in that, There are multiple H-shaped steels (2) and U-shaped steel sheet piles (3), which are evenly arranged inside the three-axis cement-soil mixing wall (1); A convex stop (6) is provided on the H-shaped steel (2), and a concave stop is provided on the U-shaped steel sheet pile (3). The H-shaped steel (2) and the U-shaped steel sheet pile (3) are connected through the convex stop and the concave stop to form a continuous combined section steel sheet pile.

3. The steel plate cement soil mixing wall structure for deep foundation pits according to claim 2, characterized in that, The convex stop (6) is a φ36 round steel, which is arranged at both ends of the flange plate on the soil-facing side of the H-shaped steel (2), and its center of the circle is arranged on the center line of the flange plate.

4. The steel sheet pile cement-soil mixing wall structure for deep foundation pit according to claim 2, characterized in that, The size of the concave stop of the U-shaped steel sheet pile (3) corresponds to the size of the convex stop (6).

5. The steel sheet pile cement-soil mixing wall structure for deep foundation pits according to claim 2, characterized in that, A waterproof sealant (7) is provided on the convex stop (6).

6. The steel sheet pile cement-soil mixing wall structure for deep foundation pits according to claim 5, characterized in that, The waterproof sealant (7) is a silane-modified polymer waterproof sealant.

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