Partitioned raft culvert structure and connection structure for deep soft soil foundation

Abstract

The present invention relates to the field of civil engineering construction, in particular to a partitioned raft culvert structure and a connection structure for a deep soft soil foundation with small settlement and weak water permeability of the culvert. The technical solution adopted by the present invention to solve its technical problems is: a partitioned raft culvert structure for a deep soft soil foundation, including a box culvert foundation unit, the box culvert foundation unit includes at least one foundation compartment, the interior of the foundation compartment is a hollow structure, the box culvert foundation unit further includes at least one box culvert structure, the foundation compartment and the box culvert structure are connected to each other, and the box culvert structure is supported by the buoyancy generated by the foundation compartment. The present invention is particularly applicable to the construction of box culvert structures.

Description

Technical Field

[0001] The present invention relates to the field of civil engineering construction, in particular to a bulkhead type ship-raft culvert structure and a connection structure for deep soft soil foundation. Background Art

[0002] For culverts in deep soft soil areas, the current specifications generally adopt composite foundations for treatment, such as mixing piles, jet grouting piles, CFG piles, and prestressed pipe piles, etc. First, construct the pile foundation to enter a certain depth of the stable bearing stratum to reinforce the deep soft soil at the base, and then set a layer of graded gravel cushion containing geogrid on the upper part of the pile foundation to form a composite foundation as the foundation of the culvert, which can reduce settlement and ensure stability. In the coastal areas of our country, there is a vast area of deep silt soft soil. The soft soil has characteristics such as high natural water content, low bearing capacity, high compressibility, and poor mechanical properties. When the culvert acts directly on the soft soil foundation, its self-weight and the additional settlement caused by the upper roadbed and vehicle loads will cause the culvert to have excessive settlement and instability and other adverse effects. Generally, composite foundations are used to treat soft soil in engineering, such as cement mixing piles, high-pressure jet grouting piles, prestressed concrete pipe piles, and CFG piles, etc. However, when using composite foundations to treat deep soft soil, there are some problems in engineering practice. It is very difficult to control the construction quality of cement mixing piles and high-pressure jet grouting piles. When the length of CFG piles is too long, it is easy to have the phenomenon of broken piles. Although the prestressed concrete pipe pile foundation has high stiffness and small settlement, its cost is very expensive. The inability to guarantee construction quality, large post-construction settlement, or high project cost has always been the main problems in the foundation treatment of culverts and other structures in deep soft soil areas, and a better method is needed to solve this problem.

[0003] The technical solution of the existing published invention patent "A culvert structure for preventing the pipeline from floating upward in soft soil" with the authorization announcement number: CN203023633 U is as follows: It includes a plurality of U-shaped bases with the same structure, the corresponding number of covers as the number of bases, and two side plates; multiple base ribs are arranged along the axis at the bottom of the U-shaped base and the lower surface of the cover. The pipeline is installed between the cover ribs and the base ribs. The U-shaped base and the cover are connected by bolts, and the two side plates are connected to the side surfaces of the U-shaped bases at both ends of the culvert structure by bolts. In the weak section or special section with shallow burial depth, the culvert structures are arranged at intervals along the pipeline laying direction outside the pipeline. The culvert structure is assembled and connected by precast reinforced concrete U-shaped bases and covers, thus artificially setting a weak section for the lateral buckling of the pipeline. The present invention adopts the method of not filling inside the culvert to weaken the horizontal restraint of the pipeline, inducing the pipeline to undergo lateral buckling deformation inside the culvert under the action of axial high stress caused by temperature rise and internal pressure in the pipeline, releasing the axial high stress, and avoiding the pipeline from floating upward and affecting the normal use of the pipeline. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a partitioned raft culvert structure and a connection structure for deep soft soil foundation with small settlement of culvert and weak water permeability.

[0005] The technical solution adopted by the present invention to solve its technical problem is: a partitioned raft culvert structure for deep soft soil foundation, including a culvert box foundation unit, the culvert box foundation unit includes at least one foundation compartment, the inside of the foundation compartment is a hollow structure, the culvert box foundation unit further includes at least one culvert box structure, the foundation compartment and the culvert box structure are connected to each other, and the culvert box structure is supported by the buoyancy generated by the foundation compartment.

[0006] Furthermore, the foundation compartments are arranged on both sides of the culvert box structure.

[0007] Furthermore, the foundation compartment is formed by enclosing a compartment middle plate and a foundation side wall.

[0008] Furthermore, the culvert box structure is a culvert box or a pipe culvert.

[0009] Furthermore, a foundation top plate is arranged on the top of the foundation compartment.

[0010] Furthermore, it includes at least two culvert box foundation units, and adjacent culvert box foundation units are connected by bolt anchor solids.

[0011] Furthermore, the bolt anchor solid includes a threaded steel bar, nuts arranged at both ends of the threaded steel bar, and steel washers sleeved on the threaded steel bar and arranged between the nuts.

[0012] Furthermore, a rubber water stop strip is arranged on the joint surface between adjacent culvert box foundation units.

[0013] Furthermore, in the overall structure formed by the connected culvert box foundation units, the culvert box foundation unit at the end is fixed by a bolt or an anchor chain.

[0014] Furthermore, the bolt or the anchor chain is fixedly connected to the culvert box foundation unit through a bolt anchor head.

[0015] The beneficial effects of the present invention are as follows: First, the culvert box foundation unit can be directly prefabricated in the factory, with flexible and simple construction, reliable quality, and short construction period. Second, there is no need to set up a composite rigid pile foundation as the culvert foundation as in the traditional construction method. The construction of the present invention has less risk, lower cost, faster construction speed, and less project investment. Third, the compartmentalized ship raft foundation has good integrity. The culvert structure can be prefabricated or cast in place as a whole, without setting settlement joints, eliminating cracks caused by uneven settlement of the culvert, and achieving water impermeability of the culvert. Fourth, the culvert foundation is compartmentalized, with a large hollow volume and relatively large buoyancy, which can offset the gravity of the culvert and the vehicle load on the upper road, realizing small settlement of the culvert. During actual construction, an anchor rod locking device is set at the foundation to achieve anti-floating under water level changes vertically and reduce the floating displacement of the foundation horizontally. The present invention is particularly suitable for the construction of culvert box structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the culvert box foundation unit of the present invention.

[0017] Figure 2 is a schematic diagram after the connection of the culvert box foundation units of the present invention forms an integral whole.

[0018] Figure 3 is a side schematic diagram after the connection of the culvert box foundation units of the present invention forms an integral whole.

[0019] Figure 4 is a schematic diagram of the bolt anchor solid of the present invention.

[0020] In the figure, the markings are: roadbed ground 1, culvert box slab 2, culvert box structure 3, anchor rod head 4, anchor rod 5, culvert box foundation unit 6, bolt anchor solid 7, foundation top slab 8, foundation compartment 9, compartment middle plate 10, foundation side wall 11, rubber water stop strip 12, soft soil 13, base covering boundary 14, bedrock 15, foundation cushion 16, threaded steel bar 17, steel gasket 18, nut 19. DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention will be further described below with reference to the accompanying drawings.

[0022] A compartmentalized ship raft culvert structure for deep soft soil foundation includes a culvert box foundation unit 6. The culvert box foundation unit 6 includes at least one foundation compartment 9, and the interior of the foundation compartment 9 is a hollow structure. The culvert box foundation unit 6 further includes at least one culvert box structure 3. The foundation compartment 9 and the culvert box structure 3 are connected to each other, and the culvert box structure 3 is supported by the buoyancy generated by the foundation compartment 9. The culvert box structure 3 can be a culvert box or a pipe culvert.

[0023] The described bulkhead-type ship-raft culvert foundation is composed of bulkhead-type ship-raft foundation units, bolt anchor solids, and a foundation anchor rod locking system. Bolts anchor multiple foundation units together to form an integral structural load-bearing foundation. The anchor rod locking system can fix the planar and vertical positions of the integral foundation. At the same time, annular rubber waterstops provided on both sides of the culvert structure can ensure the waterproof effect of the bulkhead-type ship-raft culvert foundation. In actual layout, such as Figure 1 shown, to make the buoyancy support force received by the box culvert structure 3 more balanced, it is preferred that the foundation bulkheads 9 are arranged on both sides of the box culvert structure 3. Generally, to construct the foundation bulkheads 9 at low cost, it is preferred that the foundation bulkheads 9 are formed by enclosing a bulkhead middle plate 10 and a foundation side wall 11.

[0024] In actual layout, such as Figure 2 shown by the horizontal arrow on the right in the figure, vehicles drive from right to left. To facilitate the smooth passage of vehicles through this device, a foundation top plate 8 is provided on the top of the foundation bulkheads 9.

[0025] In addition, to provide a sufficiently stable buoyancy support force, it is preferred to include at least two box culvert foundation units 6, and adjacent box culvert foundation units 6 are connected by bolt anchor solids 7. As Figure 2 shown, when connecting the box culvert foundation units 6, stable connection between the box culvert foundation units 6 can be ensured, making the construction of the box culvert structure 3 more controllable. Further, it is preferred that the bolt anchor solid 7 is composed of a threaded steel bar 17, nuts 19 provided at both ends of the threaded steel bar 17, and steel washers 18 sleeved on the threaded steel bar 17 and arranged between the nuts 19. On this basis, to prevent the influence of external accumulated water on the inside of the box culvert foundation unit 6, it is preferred that a rubber waterstop 12 is provided on the joint surface between adjacent box culvert foundation units 6. In actual connection, in the overall structure formed by the connected box culvert foundation units 6, the box culvert foundation unit 6 at the end is fixed by an anchor rod 5 or an anchor chain. The anchor rod 5 or the anchor chain is fixedly connected to the box culvert foundation unit 6 through an anchor rod head 4.

[0026] The specific construction method of the present invention is as follows: 1. Calculate the size of the culvert foundation. According to the road width and the vehicle transportation weight, determine the size of the box culvert structure 3 and the number of foundation units (for the convenience of transportation, the width of each unit can be 2 m). Considering the upper road load, the self-weight of the culvert and the foundation, the foundation buoyancy and the anchor rod tension, through the vertical force balance analysis of the foundation, calculate the size of the foundation unit and the number of partition bins, and arrange and number each unit. 2. Prefabricate the box culvert foundation unit 6. Prefabricate the box culvert foundation unit 6 in the factory, reserve the corresponding bolt anchoring hole positions, and the four anchor heads of the two outermost units (the connection stiffness between the anchor head and the foundation structure must be strengthened). If it is inconvenient to prefabricate, it can also be directly cast in place integrally on site. 3. Transport the prefabricated box culvert foundation unit 6 to the project construction site. 4. Excavate the trench, construct the cushion layer and mark the unit positions. Excavate and support the trench according to the size of the foundation. To reduce the uneven settlement of the foundation, a 20-cm-thick cushion layer is set at the bottom of the foundation, and two layers of geogrid are set in the layer. Measure and set out the line, and mark the position edges of each unit for hoisting and positioning. 5. Hoist and connect the foundation. Hoist the box culvert foundation unit 6 one by one to the specified position in the trench, adjust the foundation to the design elevation, connect the foundation of each unit with bolt anchor solids, and at the same time implement rubber water stop strips until they are in a tight state. 6. Construct the box culvert structure 3. Hoist the prefabricated box culvert structure 3 into the box culvert foundation unit 6, or pour the culvert structure in place in the foundation. 7. Construct the foundation position locking system. At the four corners of the foundation, connect the anchor rod with the anchor head to lock the plane position of the assembled culvert foundation. The anchor rod is driven into the bedrock to a certain depth to meet the requirements of the anti-floating calculation in the specification. When the thickness of the soft soil is too deep and the effect of the anchor rod is not good, the anchor chain and the anchor block can be used as the foundation locking system. 8. Construct the approach slab. To reduce the vehicle jumping phenomenon at the transition section between the culvert foundation and the road, set the transition section connection approach slab (when it is a filled subgrade, there is no need to set the approach slab). 9. Complete the road and pavement construction.

Claims

1. The connecting structure formed by the bulkhead type ship-raft culvert structure on deep soft soil foundation, including the bulkhead type ship-raft culvert structure on deep soft soil foundation, the bulkhead type ship-raft culvert structure on deep soft soil foundation includes a culvert box foundation unit (6), the culvert box foundation unit (6) includes at least one foundation compartment (9), the inside of the foundation compartment (9) is a hollow structure, the culvert box foundation unit (6) further includes at least one culvert box structure (3), the foundation compartment (9) and the culvert box structure (3) are connected to each other, the culvert box structure (3) is supported by the buoyancy generated by the foundation compartment (9), the foundation compartment (9) is arranged on both sides of the culvert box structure (3), the foundation compartment (9) is surrounded by a compartment middle plate (10) and a foundation side wall (11), the culvert box structure (3) is a culvert box or a pipe culvert, and a foundation top plate (8) is arranged on the top of the foundation compartment (9), and it is characterized in that: It includes at least two culvert box foundation units (6), and adjacent culvert box foundation units (6) are connected by bolt anchor solids (7); the bolt anchor solids (7) are composed of threaded steel bars (17), nuts (19) arranged at both ends of the threaded steel bars (17), and steel washers (18) sleeved on the threaded steel bars (17) and arranged between the nuts (19).

2. The connecting structure formed by the partitioned raft culvert structure using deep soft soil foundation as claimed in claim 1, characterized in that: A rubber water stop strip (12) is arranged on the joint surface between adjacent culvert box foundation units (6).

3. The connecting structure formed by the partitioned raft culvert structure on deep soft soil foundation according to claim 1, characterized in that: In the overall structure formed by the connected culvert box foundation units (6), the culvert box foundation units (6) at the end are fixed by anchor rods (5) or anchor chains.

4. The connecting structure formed by the partitioned raft culvert structure using deep soft soil foundation as described in claim 3, characterized in that: The anchor rods (5) or anchor chains are fixedly connected with the culvert box foundation units (6) through anchor rod anchor heads (4).

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