Supporting system based on double-row steel sheet piles and grouting steel pipe piles and construction method

Abstract

The invention relates to the technical field of building construction, in particular to a supporting system based on double-row steel sheet piles and grouting steel pipe piles and a construction method, the supporting system comprises inner-row steel sheet piles, outer-row steel sheet piles and steel enclosing purlins, and the inner-row steel sheet piles and the outer-row steel sheet piles comprise the inner-row steel sheet piles and the outer-row steel sheet piles; the inner-row steel sheet piles and the outer-row steel sheet piles are arranged in parallel and then are connected in a welded mode through steel enclosing purlins, and triangular steel brackets are arranged at the positions, connected with the inner-row steel sheet piles and the outer-row steel sheet piles, below the steel enclosing purlins. According to the technical scheme, the inner row steel sheet piles and the outer row steel sheet piles are connected into an overall stress system, compared with cantilever type steel sheet piles, stress is definite, deformation of the steel sheet piles is small, safety is good, the steel sheet piles are suitable for large excavation depth, influences on peripheral pipelines are avoided, and then cost is saved.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, and in particular to a support system and a construction method based on double-row steel sheet piles and grouting steel pipe piles. Background Art

[0002] With the needs of engineering construction, deep foundation pits of various soil types have appeared. In foundation pit projects in soft soil areas, single-row support structures have been widely used, but the disadvantages of single-row support structures are: large horizontal displacement of the top and poor bending resistance. In projects with strict requirements on foundation pit deformation, single-row pile support structures are somewhat inadequate. As a new structural form, double-row pile support structures effectively overcome the shortcomings of single-row pile support structures, and the investment cost is almost the same as that of single-row pile support structures. There is no need for internal support, which increases the working surface for construction and has a high application value.

[0003] Double-row steel sheet pile foundation pit and cofferdam is one of the widely used support forms in municipal and water conservancy projects on soft soil foundations. It has the advantages of small size, small impact range, reliable water stopping, ability to withstand large deformation and fast construction speed. The structure still uses a semi-theoretical and semi-empirical design method based on experience. It is difficult to accurately predict the adverse conditions that may occur during the construction process, and there are great limitations in structural reliability analysis. The research on the stress and deformation of the double-row pile support structure and the mechanism of pile-soil interaction needs to be further improved.

[0004] In municipal projects with many pipelines around the foundation pit, when internal support cannot be constructed, cantilever double-row steel sheet pile support is mainly used. The cantilever double-row steel sheet pile construction has the following disadvantages: 1. The steel sheet piles have not formed an integral system and have large deformation; 2. Applicable to shallow foundation pit depth; Therefore, there is an urgent need for a support system and construction method of double-row steel sheet piles + advanced grouting steel pipe piles. Summary of the invention In order to solve the above-mentioned problems, the present invention provides a support system and construction method based on double-row steel sheet piles and grouting steel pipe piles. This support method can solve the problem that the excavation depth of the foundation pit is large, the soil layer is relatively weak, and the steel sheet piles are prone to large deformation. By setting double-row inter-pile supports and grouting steel pipe supports inside the foundation pit to provide horizontal force and resist horizontal deformation, compared with the commonly used cantilever double-row steel sheet pile support, the horizontal internal support and the oblique steel pipe support can effectively avoid the problem of excessive deformation of the steel sheet piles, providing a reliable support form, which can provide method guidance for the foundation pit support construction in similar municipal, water conservancy and construction projects where anchor cables cannot be constructed and the support length is too long.

[0005] In the first aspect, the present invention provides a support system based on double-row steel sheet piles and grouting steel pipe piles, which adopts the following technical solution: A support system based on double-row steel sheet piles and grouting steel pipe piles, comprising: Inner and outer rows of steel sheet piles and steel perimeter purlins, the inner and outer rows of steel sheet piles include inner row steel sheet piles and outer row steel sheet piles, wherein the inner row steel sheet piles and outer row steel sheet piles are arranged in parallel and then welded and connected by steel perimeter purlins, and a triangular steel bracket is arranged at the connection between the lower part of the steel perimeter purlin and the inner and outer rows of steel sheet piles.

[0006] Furthermore, the steel perimeter purlin adopts an H-shaped steel perimeter purlin, wherein the steel perimeter purlin of the front row of steel sheet piles and the steel perimeter purlin of the rear row of steel sheet piles are welded and connected through steel supports.

[0007] Furthermore, a front-support grouting steel pipe column is connected to the side of the steel perimeter purlin, one end of the front-support grouting steel pipe column is connected to the steel perimeter purlin through a flexible head, and the other end is fixed to the ground, forming a triangular structure for supporting the steel perimeter purlin.

[0008] Furthermore, a water-stop steel plate is provided at one end of the front-support grouting steel pipe column connected to the ground to prevent the influx of groundwater.

[0009] Furthermore, a grouting pipe and a grouting bag belt are arranged inside the front support grouting steel pipe column, and the grouting liquid is gathered into the grouting bag belt through the grouting pipe.

[0010] In a second aspect, a construction method of a support system based on double-row steel sheet piles and grouting steel pipe piles comprises: Construction of external steel sheet piles; Partial excavation of soil inside two rows of steel sheet piles; Carry out inner row steel sheet pile construction; Carry out the construction of grouting steel pipe column and grouting the inside of the steel pipe column; Carry out steel purlin and steel support construction; Connect the inner row of steel sheet piles with the steel pipe piles to complete the construction.

[0011] Furthermore, the construction of the external row of steel sheet piles includes constructing the external row of steel sheet piles in the foundation pit for water isolation.

[0012] Furthermore, the soil inside the two rows of steel sheet piles is partially excavated, including excavating the soil between the inner and outer rows of steel sheet piles to 300 mm below the top of the inner row of steel sheet piles.

[0013] Furthermore, the inner row steel sheet pile construction includes pressing the inner steel sheet piles into the soil using a static pile pressing method.

[0014] Furthermore, the construction of the grouting steel pipe column and grouting the inside of the steel pipe column include installing the grouting steel pipe column, connecting one end of the grouting steel pipe column to the steel perimeter purlin through a flexible head, connecting the other end to the ground, and grouting the construction constraint body.

[0015] Furthermore, the construction of the steel perimeter purlin and the steel support includes respectively fixing the inner and outer rows of steel sheet piles to the steel perimeter purlin, and arranging a steel support in the middle of the steel perimeter purlin for fixing.

[0016] In summary, the present invention has the following beneficial technical effects: The present invention connects the inner and outer rows of steel sheet piles into an integral force-bearing system through the above technical scheme. Compared with cantilever steel sheet piles, the force is clear, the deformation of the steel sheet piles is small, the safety is good, it is suitable for deeper excavation depths, avoids affecting surrounding pipelines, and thus saves costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the support system according to the embodiment of the present invention.

[0018] Figure 2 It is a cross-sectional schematic diagram of a support system according to an embodiment of the present invention.

[0019] Figure 3 Schematic diagram of a support system according to an embodiment of the present invention.

[0020] Figure 4 It is a partial enlarged schematic diagram of the movable head of the support system of an embodiment of the present invention.

[0021] Among them, 1. Outer row steel sheet piles; 2. Inner row steel sheet piles; 3. Steel purlin; 4. Steel support; 5. Front support grouting steel pipe column; 6. Steel bracket; 7. Waterstop steel plate; 8. Grouting bag belt; 9. Constraint; 10. Active head; 11. Shear reinforcement plate; 12. Steel pad box; 13. Reinforcement plate. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0023] Example 1 Reference Figure 1 , a support system based on double-row steel sheet piles and grouting steel pipe piles of this embodiment includes: Inner and outer rows of steel sheet piles and steel purlins, the inner and outer rows of steel sheet piles include inner row steel sheet piles and outer row steel sheet piles, wherein the inner row steel sheet piles and outer row steel sheet piles are arranged in parallel and connected by welding through steel purlins, and a triangular steel bracket is arranged below the steel purlins and at the connection between the inner and outer rows of steel sheet piles. The steel purlins adopt H-shaped steel purlins, wherein the steel purlins of the front row of steel sheet piles and the steel purlins of the rear row of steel sheet piles are connected by welding through steel supports. The side of the steel purlins is connected with a front support grouting steel pipe column, one end of the front support grouting steel pipe column is connected to the steel purlin through a flexible head, and the other end is fixed to the ground, forming a triangular structure for supporting the steel purlins. A water-stop steel plate is arranged at one end of the front support grouting steel pipe column connected to the ground to prevent the influx of groundwater. The front support grouting steel pipe column is provided with a grouting pipe and a grouting bag belt inside, and the grouting liquid is gathered into the grouting bag belt through the grouting pipe.

[0024] Among them, Figure 1 As shown, the front row of steel sheet piles 1 and the rear row of steel sheet piles 2 are respectively connected to the steel purlin 3 by welding, and a triangular steel bracket 6 is arranged under the steel purlin 3; the steel purlin 3 is connected to the steel support 4 by welding; the connection between the two is achieved by welding the end of the steel support to the connection steel plate pre-arranged on the steel purlin or directly to the steel purlin body. The steel purlin 3 is connected to the front support grouting steel pipe pile 5, wherein the back connection is consistent with the connection method of the steel purlin 3) and the steel support 4; the outer connection: welding by connecting parts: first weld a connecting steel plate or a special connecting member on the steel sheet pile, and then weld the diagonal brace joint head to the connecting steel plate. A connecting steel plate with bolt holes or slots is pre-welded on the steel sheet pile, and the diagonal brace joint head is welded and fixed after matching with these bolt holes or slots, which can increase the reliability and flexibility of the connection.

[0025] The vertical joints of two adjacent steel sheet piles should be staggered up and down, and the staggered distance should not be greater than 1m.

[0026] The front support grouting steel pipe 5 is connected to the steel purlin 3 through a flexible joint 10; a water stop steel plate 7 is arranged at the position where the front support grouting steel pipe 5 contacts the ground to prevent groundwater from pouring in; The grouting bag 9 is provided with a grouting pipe inside the front support grouting steel pipe 5 to collect the grouting liquid into the bag.

[0027] like Figure 4 As shown, the steel purlin 3 is used to connect the support and the retaining pile, plays the role of fixing the steel support and transferring the load, and is widely used in foundation pit support engineering. Structure: Generally, single or double beams or steel sections of the same model and length are used for splicing. The quality must be ensured during splicing so that multiple steel sections are stressed together. In large foundation pit construction, steel purlins are widely used because of their large rigidity, convenient construction, and recyclability.

[0028] The reinforcing plate 13 is arranged inside the steel purlin to enhance the strength, rigidity and stability of the structural member, improve the structural member's ability to resist deformation and damage, and reduce deformation and stress concentration under load. In the steel purlin, the reinforcing plate is usually welded between the flanges of the steel to strengthen the structure of the steel purlin.

[0029] The steel pad box 12 is used for connection and padding between the steel support and the retaining structure wall during deep foundation pit construction, which can ensure the safety of the deep foundation pit retaining structure and facilitate the installation and removal of the steel support.

[0030] The shear reinforcement plate 11 is mainly used to improve the shear resistance of the structure, enhance the bearing capacity and stability of the structure under the action of shear force, and prevent the structure from failing due to shear damage. It is usually arranged and designed according to the stress characteristics and design requirements of the structure, and is generally made of steel plates and other materials, and is connected to the main structure by welding or bolting.

[0031] The flexible head 10 is a structural component used to adjust the extension length of the steel support and apply prestress, especially in the application technology of foundation pit support construction. The following is a detailed introduction to the steel support flexible head: Structural composition Traditional structure: generally, the end steel plate, channel steel telescopic rod, stiffening rib plate and other parts are assembled and welded into a movable end, and the channel steel telescopic rod is placed in the steel pipe at the movable end to form a structure similar to a "drawer". This structure is simple and easy to construct and install. The support length is adjusted by the expansion and contraction of the channel steel telescopic rod in the steel pipe.

[0032] Improved structure: Take a new type of steel support joint as an example, including a female plug, a male plug, a plug positioning mechanism and several plug pins. A flange is welded at one end of the barrel of the female plug, and slots are opened at equal distances around the circumference at the other end; the cavity main board and bottom rib plate of the plug positioning mechanism are stuck in the slots at the corresponding positions of the end of the barrel and fixed by welding; a plug rod is welded in the middle of the front of the male bottom plate of the male plug, which is plugged with the socket of the female plug, and there is a wedge groove between the plug rods, and the pin is inserted in the wedge groove.

[0033] Working principle: During the construction of foundation pit support, when the length of the steel support needs to be adjusted to adapt to different foundation pit sizes and force requirements, the hydraulic jack acts on the movable end of the flexible head to allow the channel steel telescopic rod to expand and contract in the steel pipe at the movable end, thereby changing the overall length of the steel support. When the required support length is reached, the position of the flexible head is fixed by means of bolts, positioning screws and other components, so that the steel support can stably withstand the pressure of the soil around the foundation pit.

[0034] Example 2 The difference between this embodiment and embodiment 1 is that this embodiment provides a construction method of a support system based on double-row steel sheet piles and grouting steel pipe piles, including: Construction of external steel sheet piles; Partial excavation of soil inside two rows of steel sheet piles; Carry out inner row steel sheet pile construction; Carry out the construction of grouting steel pipe column and grouting the inside of the steel pipe column; Carry out steel purlin and steel support construction; Connect the inner row of steel sheet piles with the steel pipe piles to complete the construction.

[0035] The construction of the outer row of steel sheet piles includes the construction of the outer row of steel sheet piles for water isolation. The partial excavation of the soil inside the two rows of steel sheet piles includes the excavation of the soil between the inner and outer rows of steel sheet piles to 300mm below the top of the inner row of steel sheet piles. The construction of the inner row of steel sheet piles includes the use of the static pile pressure method to press the inner steel sheet piles into the soil. The construction of the grouting steel pipe column and the grouting of the inside of the steel pipe column include the installation of the grouting steel pipe column, connecting one end of the grouting steel pipe column to the steel purlin through a flexible head, connecting the other end to the ground, and grouting the construction constraint. The construction of steel purlins and steel supports includes the fixed connection of the inner and outer rows of steel sheet piles to the steel purlins, respectively, and setting a steel support in the middle of the steel purlin for fixing.

[0036] in, Pre-construction preparation The construction site is leveled and cleaned to ensure that the site is ready for construction. At the same time, measurements are taken to determine the location and size of the foundation pit.

[0037] Prepare the necessary construction materials and equipment, including outer row steel sheet piles, inner row steel sheet piles, H-shaped steel purlins, steel supports, front support grouting steel pipe columns, waterstop steel plates, grouting pipes, grouting bag belts, as well as static pile driving equipment, welding equipment, hydraulic jacks, etc.

[0038] Construction of external steel sheet piles According to the design requirements, the steel sheet piles are constructed around the foundation pit. Use appropriate piling equipment, such as a vibrating hammer or a static pile driver, to drive the steel sheet piles into the soil one by one, ensuring that the verticality and depth of the steel sheet piles meet the requirements so that they can play a role in water isolation. During the piling process, pay attention to controlling the piling speed and force to avoid causing excessive disturbance to the surrounding soil.

[0039] Partial excavation of soil inside two rows of steel sheet piles Use excavators and other equipment to excavate the soil between the inner and outer rows of steel sheet piles, and the excavation depth should be 300mm below the top of the inner row of steel sheet piles. During the excavation process, it is necessary to pay attention to layered and segmented excavation. The excavation depth of each layer should not be too large, generally controlled at 2-3m, and the excavation surface should be supported in time to prevent soil collapse. At the same time, the displacement and deformation of the soil should be closely monitored. If there is any abnormality, the excavation should be stopped immediately and corresponding measures should be taken.

[0040] Carry out internal steel sheet pile construction Use the static pile-pressing method to press the inner steel sheet pile into the soil. Before pressing the pile, check the quality of the steel sheet pile to ensure that it is not deformed or damaged. During the pile-pressing process, strictly control the pile-pressing force and speed to ensure that the verticality and burial depth of the steel sheet pile meet the design requirements. The vertical joints of two adjacent steel sheet piles should be staggered up and down, and the staggered distance should not be greater than 1m to enhance the integrity of the support structure.

[0041] Carry out the construction of grouting steel pipe column and grouting the inside of the steel pipe column Install the grouting steel pipe column, connect one end of it to the steel purlin through a flexible joint, and connect the other end to the ground. During the connection process, ensure that the connection is firm and reliable. Install a water-stop steel plate at one end of the steel pipe column connected to the ground to prevent groundwater from pouring in.

[0042] During the grouting operation, the grouting liquid is injected into the grouting bag belt inside the steel pipe column through the grouting pipe to expand the grouting bag belt, thereby enhancing the friction and adhesion between the steel pipe column and the soil, and improving the stability of the support structure. During the grouting process, the grouting pressure and grouting volume must be controlled to ensure the grouting effect.

[0043] Carry out steel purlin and steel support construction The inner and outer rows of steel sheet piles are fixedly connected to the steel purlins, and welding is used to ensure a firm connection. The steel purlins are H-shaped steel purlins. The steel purlins of the front row of steel sheet piles and the steel purlins of the rear row of steel sheet piles are welded and connected through steel supports. Steel supports are set in the middle of the steel purlins for fixing to enhance the overall rigidity of the support structure. When installing the steel supports, a hydraulic jack should be used to apply a certain amount of prestress to them so that they can better play a supporting role.

[0044] Connect the inner row of steel sheet piles with the steel pipe piles to complete the construction The inner row of steel sheet piles are connected to the steel pipe piles by welding or other reliable connection methods to form a complete support system.

[0045] Conduct a comprehensive inspection of the completed support system, including the verticality of the steel sheet piles, the connection between the steel purlins and the steel supports, the grouting effect, etc., to ensure that the support system meets the design requirements and safety standards. During the foundation pit construction process, the support system should be monitored and maintained regularly to promptly identify and handle possible problems.

[0046] During the entire construction process, operations must be carried out strictly in accordance with design requirements and relevant specifications to ensure construction quality and safety. At the same time, the construction methods must be appropriately adjusted and optimized according to actual construction conditions, such as geological conditions and surrounding environment.

[0047] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A support system based on double-row steel sheet piles and grouting steel pipe piles, characterized in that: include: Inner and outer rows of steel sheet piles and steel perimeter purlins, the inner and outer rows of steel sheet piles include inner row steel sheet piles and outer row steel sheet piles, wherein the inner row steel sheet piles and outer row steel sheet piles are arranged in parallel and then welded and connected by steel perimeter purlins, and a triangular steel bracket is arranged at the connection between the lower part of the steel perimeter purlin and the inner and outer rows of steel sheet piles.

2. A support system based on double-row steel sheet piles and grouting steel pipe piles according to claim 1, characterized in that: The steel perimeter purlin adopts H-shaped steel perimeter purlin, wherein the steel perimeter purlin of the front row of steel sheet piles and the steel perimeter purlin of the rear row of steel sheet piles are welded and connected through steel supports.

3. A support system based on double-row steel sheet piles and grouting steel pipe piles according to claim 2, characterized in that: A front-support grouting steel pipe column is connected to the side of the steel perimeter purlin. One end of the front-support grouting steel pipe column is connected to the steel perimeter purlin through a flexible head, and the other end is fixed to the ground to form a triangular structure for supporting the steel perimeter purlin.

4. A support system based on double-row steel sheet piles and grouting steel pipe piles according to claim 3, characterized in that: One end of the front support grouting steel pipe column connected to the ground is provided with a water-stopping steel plate to prevent the influx of groundwater.

5. A support system based on double-row steel sheet piles and grouting steel pipe piles according to claim 4, characterized in that: The front support grouting steel pipe column is provided with a grouting pipe and a grouting bag belt inside, and the grouting liquid is gathered into the grouting bag belt through the grouting pipe.

6. A construction method for a support system based on double-row steel sheet piles and grouting steel pipe piles, characterized in that: include: Partial excavation of soil inside two rows of steel sheet piles; Carry out the construction of outer row steel sheet piles and inner row steel sheet piles in sequence; Carry out the construction of grouting steel pipe column and grouting the inside of the steel pipe column; Carry out steel purlin and steel support construction; Connect the inner row of steel sheet piles with the steel pipe piles to complete the construction.

7. The construction method of a support system based on double-row steel sheet piles and grouting steel pipe piles according to claim 6 is characterized in that: The partial excavation of the soil inside the two rows of steel sheet piles includes excavating the soil between the inner and outer rows of steel sheet piles to 300 mm below the top of the inner row of steel sheet piles.

8. The construction method of the support system based on double-row steel sheet piles and grouting steel pipe piles according to claim 7 is characterized in that: The outer row of steel sheet piles and the inner row of steel sheet piles are constructed in sequence, including constructing the outer row of steel sheet piles for water isolation, and using the static pile pressing method to press the inner steel sheet piles into the soil.

9. The construction method of the support system based on double-row steel sheet piles and grouting steel pipe piles according to claim 8, characterized in that: The construction of the grouting steel pipe column and grouting the inside of the steel pipe column include installing the grouting steel pipe column, connecting one end of the grouting steel pipe column to the steel purlin through a flexible head, connecting the other end to the ground, and grouting the construction constraint body.

10. The construction method of the support system based on double-row steel sheet piles and grouting steel pipe piles according to claim 9, characterized in that: The steel perimeter purlin and steel support construction comprises respectively fixing the inner and outer rows of steel sheet piles to the steel perimeter purlin, and arranging a steel support in the middle of the steel perimeter purlin for fixing.

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