Open caisson structure suitable for soft rock dynamic side slope

Abstract

The utility model relates to the technical field of open caisson equipment, in particular to an open caisson structure suitable for a soft rock dynamic side slope, which comprises a retaining wall, the retaining wall adopts a cylindrical structure with an upper opening and a lower opening, a top ring is mounted at the top of the retaining wall, a stone laying layer is mounted at the bottom opening of the retaining wall, a winding pipe is arranged on the inner side of the retaining wall, and a well cover is mounted at the top of the top ring. A water pump support is placed on the well lid. In the open caisson structure suitable for the soft rock dynamic side slope, the retaining wall is of a structure that the concrete layer is poured outside the steel bar frame, and the overall bearing capacity and deformation resistance of the open caisson can be enhanced. Compared with a traditional open caisson, the open caisson can better adapt to complex geological conditions of a soft rock dynamic side slope and effectively resist influences caused by rock weathering and breaking and external load changes, so that side slope displacement is accurately controlled, the stability of the side slope in the long-term using process is guaranteed, and the risk of occurrence of disasters such as landslide is reduced.

Description

Technical Field

[0001] This utility model relates to the field of caisson equipment technology, and more specifically, to a caisson structure suitable for dynamic soft rock slopes. Background Technology

[0002] In the field of geological engineering, the stability of dynamic soft rock slopes has always been a key challenge in engineering construction. Soft rock is characterized by low strength, large deformation, and softening upon contact with water. During the slope formation process, it is highly susceptible to factors such as groundwater seepage, weathering, and changes in external loads, leading to frequent slope instability, landslides, and other disasters that seriously threaten the safety of surrounding engineering facilities and the lives and property of people.

[0003] Currently, some publicly disclosed caisson structures for the protection and reinforcement of dynamic soft rock slopes have revealed numerous problems in practical applications. For example, the patent application No. 201110032185.0, "A Reinforced Concrete Caisson Construction Method for Soft Soil Strata," while avoiding the need for deep excavation and reducing sudden sinking of the caisson to some extent, primarily focuses on soft soil strata. It does not adequately consider the complex geological characteristics of dynamic soft rock slopes, such as rock weathering and fracturing, as well as the dynamic changes in groundwater. Consequently, it struggles to effectively control slope displacement and fails to meet the stringent stability requirements of dynamic soft rock slopes for caisson structures.

[0004] For example, the patent CN217325444U, "A Combined Caisson Applicable to Rock," is mainly suitable for "hard rock." During construction and excavation, the rock sidewalls will not weather or collapse, and the construction method is a forward-facing approach. However, the excavation of soft rock in dynamic slopes is difficult, and large-scale weathering, detachment, and collapse are prone to occur during the excavation process. The structure and construction method of this patent are not suitable for dynamic slopes of soft rock, and if forcibly applied, it will bring great safety hazards.

[0005] Furthermore, some caisson structures perform poorly in terms of drainage. For example, some traditional caissons lack a properly designed drainage system, failing to promptly remove accumulated water from the slope. This causes the soft rock to further weaken due to prolonged immersion in water, exacerbating the risk of slope instability. Additionally, some caissons are not designed with sufficient consideration for future monitoring and maintenance needs, making it difficult to install drainage and testing equipment and thus hindering real-time and effective monitoring of the slope's condition. Utility Model Content

[0006] The purpose of this invention is to provide a caisson structure suitable for dynamic soft rock slopes, in order to solve the problem mentioned in the background art that the complex geological characteristics of dynamic soft rock slopes, such as rock weathering and fracturing and dynamic changes in groundwater, are not adequately considered, making it difficult to effectively control slope displacement and meet the stringent requirements of dynamic soft rock slopes for the stability of the caisson structure.

[0007] To achieve the above objectives, this utility model provides a caisson structure suitable for dynamic slopes of soft rock, including a retaining wall. The retaining wall adopts a cylindrical structure with openings at the top and bottom. A top ring is installed at the top of the retaining wall, and a masonry layer is installed at the bottom opening of the retaining wall. A winding pipe is provided on the inner side of the retaining wall, and a well cover is installed at the top of the top ring. A water pump bracket is placed on the well cover.

[0008] This system employs a cylindrical retaining wall structure, utilizing the uniform stress characteristics of a circular cross-section to effectively resist lateral pressure from dynamic soft rock slopes. A top ring enhances the structural strength of the retaining wall, preventing wellhead collapse; a masonry layer serves as bottom support, distributing the caisson's own weight and external loads, preventing excessive disturbance of the bottom soil during caisson sinking. A spiral pipe located inside the caisson serves as the main drainage channel, guiding groundwater into the well; the well cover and pump support provide a foundation for the subsequent installation of drainage equipment.

[0009] Preferably, a plurality of hydrophobic sleeves are installed in the middle of the protective wall, and the hydrophobic sleeves are arranged in a ring at equal intervals along the inner wall of the protective wall, with a spacing of 1000mm.

[0010] This design involves arranging drainage sleeves at equal intervals in a ring along the inner wall of the retaining wall to form a uniform drainage network. The 1000mm spacing is based on calculations of the permeability coefficient of soft rock and the hydraulic gradient to ensure effective coverage of the seepage area on the slope.

[0011] Preferably, the hydrophobic sleeve is made of metal or rigid plastic, with one end extending to the outside of the protective wall and the other end located on the inside of the protective wall.

[0012] This feature utilizes metal or rigid plastic materials to ensure the durability of the casing in long-term groundwater environments, resisting chemical corrosion and physical abrasion. One end extends to the outside of the retaining wall, directly contacting the slope's soil and rock mass, while the other end is located on the inside, forming a gravity flow drainage channel.

[0013] Preferably, the top ring is 1.2 meters above the ground, supported by clay bricks, and coated with an M7.5 cement mortar layer on the outside.

[0014] The top ring of this structure is 1.2 meters above the ground, forming an erosion barrier to prevent surface runoff from directly entering the caisson. The combination of clay brick masonry and cement mortar finishing ensures structural strength while utilizing the micro-permeability of the clay bricks to reduce surface water infiltration.

[0015] Preferably, the retaining wall includes a steel reinforcement frame, and a concrete layer is poured outside the steel reinforcement frame.

[0016] This design utilizes a steel reinforcement frame to provide tensile strength and a concrete layer to provide compressive strength, working together to form a reinforced concrete structure. This composite structure can adapt to uneven settlement and deformation of dynamic soft rock slopes, preventing cracking of the retaining wall.

[0017] Preferably, the masonry layer is formed by dry-laying a mixture of small pebbles (15-30mm) and large pebbles (20-30mm).

[0018] This design uses a mixture of pebbles of different sizes, dry-laid to form a porous, permeable structure. Small pebbles fill the gaps between larger pebbles, ensuring both structural permeability and sufficient load-bearing capacity.

[0019] Preferably, the bottom end of the spiral wound tube is inserted into the masonry layer, and the depth of insertion into the masonry layer is not less than 300mm.

[0020] This design ensures the spiral wound pipe is inserted into the masonry layer to a depth of at least 300mm, guaranteeing effective contact between the pipe and the filter layer. This embedded design prevents the bottom of the spiral wound pipe from being suspended, thus preventing groundwater from flowing around the bottom of the pipe.

[0021] Preferably, the spiral tube is a permeable material tube with an outer diameter of 1200-1400mm, and the tube wall is provided with evenly distributed permeable holes for slope drainage.

[0022] This design features a large diameter of 1200-1400mm, providing sufficient cross-sectional area for water flow and reducing water resistance. The evenly distributed perforations ensure that groundwater can enter the pipe from all directions around its perimeter.

[0023] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0024] This caisson structure, suitable for dynamic soft rock slopes, features a reinforced concrete outer layer for the retaining wall, enhancing the overall load-bearing capacity and deformation resistance of the caisson. Compared to traditional caissons, it better adapts to the complex geological conditions of dynamic soft rock slopes, effectively resisting the effects of rock weathering, fracturing, and changes in external loads. This allows for precise control of slope displacement, ensuring slope stability during long-term use and reducing the risk of landslides and other disasters.

[0025] The drainage system is constructed by annularly spaced drainage sleeves in the middle of the retaining wall, combined with the permeable structure of the inner spiral pipe. The drainage sleeves divert accumulated water from the slope to the inside of the caisson, while the spiral pipe further collects and discharges the water. Compared to the poor drainage of traditional caissons, this structure can quickly and effectively drain water from the slope, preventing the soft rock from weakening due to long-term immersion in water and fundamentally improving the stability of the slope.

[0026] The top ring is 1.2 meters above the ground and is constructed with clay bricks and plastered with cement mortar. The top of the manhole cover can also accommodate a water pump bracket, facilitating the later installation of submersible pumps, piezometers, level gauges, and other drainage and monitoring equipment. This design overcomes the shortcomings of existing caissons in terms of equipment installation and monitoring, enabling real-time monitoring of the slope condition, facilitating timely problem detection and maintenance, and ensuring the long-term safe operation of the slope project. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0028] Figure 2 This is a schematic diagram of the protective wall structure in this utility model;

[0029] Figure 3 This is a schematic diagram of the top structure of this utility model;

[0030] Figure 4 This is a schematic diagram of the structure of the water pump bracket in this utility model;

[0031] The meanings of the labels in the diagram are as follows:

[0032] 1. Retaining wall; 11. Reinforcing steel frame; 12. Concrete layer; 2. Top ring; 3. Manhole cover; 4. Spiraling pipe; 5. Masonry layer; 6. Drainage sleeve; 7. Pump support; 71. Crossbar; 72. Support leg. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0034] This utility model provides a caisson structure suitable for dynamic slopes in soft rock, such as... Figure 1 , Figure 2 , Figure 3 As shown, the structure includes a retaining wall 1, which is a cylindrical structure with openings at the top and bottom. A top ring 2 is installed at the top of the retaining wall 1, and a masonry layer 5 is installed at the bottom opening of the retaining wall 1. A spiral pipe 4 is installed on the inner side of the retaining wall 1. A manhole cover 3 is installed on the top of the top ring 2, and a water pump bracket 7 is placed on the manhole cover 3. The water pump bracket 7 includes a crossbar 71, and support feet 72 are installed at the bottom of both ends of the crossbar 71.

[0035] The structure employs a cylindrical retaining wall 1 with openings at both the top and bottom. Utilizing the uniform stress distribution characteristic of a circular cross-section, it effectively resists lateral pressure from dynamic soft rock slopes. The top ring 2 enhances the structural strength of the top of the retaining wall 1, preventing wellhead collapse. The masonry layer 5 at the bottom opening of the retaining wall 1 serves as a bottom support, distributing the caisson's self-weight and external loads, preventing excessive disturbance of the bottom soil during caisson sinking. The inner spiral pipe 4 serves as the main drainage channel, guiding groundwater into the well. The well cover 3 on top of the top ring 2 and the pump bracket 7 placed on it provide a foundation for the subsequent installation of drainage equipment. The overall structural stability is significantly improved, better adapting to the complex geological conditions of dynamic soft rock slopes and reducing the risk of structural damage due to slope deformation. Simultaneously, interfaces are reserved for the installation of subsequent drainage and monitoring equipment, enhancing the functionality and scalability of the caisson.

[0036] In this embodiment, as Figure 1 As shown, several drainage sleeves 6 are installed in the middle of the protective wall 1. The drainage sleeves 6 are arranged in a ring at equal intervals along the inner wall of the protective wall 1, with a spacing of 1000mm.

[0037] Several drainage sleeves 6 are installed in the middle of the retaining wall 1, and are arranged in a ring at equal intervals of 1000mm along the inner wall of the retaining wall 1. This ring distribution forms a uniform drainage network. The spacing design is based on the permeability coefficient of soft rock and hydraulic gradient calculations, which can ensure effective coverage of the seepage area of ​​the slope. It can efficiently guide groundwater from the slope into the caisson, reduce pore water pressure, and reduce the strength reduction of soft rock caused by water soaking. The ring distribution avoids local water accumulation and improves the overall drainage efficiency.

[0038] Specifically, such as Figure 1 As shown, the hydrophobic sleeve 6 is made of metal or rigid plastic, with one end extending to the outside of the protective wall 1 and the other end located inside the protective wall 1.

[0039] The drainage sleeve 6 is made of metal or rigid plastic, ensuring its durability in long-term groundwater environments and resisting chemical corrosion and physical abrasion. One end extends to the outside of the retaining wall 1, directly contacting the slope soil and rock, while the other end is located inside the retaining wall 1, forming a gravity flow drainage channel. This extends the sleeve's service life, reduces maintenance costs, and the reliable material selection ensures long-term effective drainage. The through-flow design allows for natural groundwater diversion without the need for additional power equipment.

[0040] Furthermore, such as Figure 1 As shown, the top ring 2 is 1.2 meters above the ground, supported by clay bricks, and coated with an M7.5 cement mortar layer on the outside.

[0041] The top ring 2, rising 1.2 meters above ground level, forms an erosion barrier, preventing surface runoff from directly entering the caisson. Constructed with clay bricks and coated with an M7.5 cement mortar layer on the outside, it ensures structural strength while utilizing the micro-permeability of the clay bricks to reduce surface water infiltration. This effectively prevents rainwater and surface water erosion of the wellhead, protecting the structural integrity of the caisson's top. Simultaneously, it reduces the risk of shallow slope slippage caused by surface water infiltration.

[0042] Furthermore, such as Figure 2 As shown, the retaining wall 1 includes a steel reinforcement frame 11, and a concrete layer 12 is poured outside the steel reinforcement frame 11.

[0043] The retaining wall 1 consists of a steel reinforcement frame 11 and an externally poured concrete layer 12. The steel reinforcement frame 11 provides tensile strength, while the concrete layer 12 provides compressive strength. Together, they form a reinforced concrete structure that can adapt to the uneven settlement and deformation of soft rock dynamic slopes, preventing cracking of the retaining wall 1. This significantly improves the overall strength and deformation resistance of the retaining wall 1, ensuring the structural stability of the caisson during long-term use. Moreover, reinforced concrete has better durability than traditional materials, reducing structural degradation caused by environmental erosion.

[0044] Furthermore, such as Figure 1 As shown, the masonry layer is made by dry-laying a mixture of small pebbles (15-30mm) and large pebbles (20-30mm).

[0045] The masonry layer 5 is composed of a dry-laid mixture of small pebbles (15-30mm) and large pebbles (20-30mm), forming a porous and permeable structure. The small pebbles fill the gaps between the large pebbles, ensuring both structural permeability and sufficient load-bearing capacity. Masonry layer 5 acts as a natural filter layer, allowing groundwater infiltration while preventing sediment loss and piping. The dry-laying process facilitates construction and subsequent maintenance, and the pebble gradation can be adjusted according to actual geological conditions.

[0046] Furthermore, such as Figure 1 As shown, the bottom end of the spiral tube 4 is inserted into the masonry layer 5, and the depth of insertion into the masonry layer 5 is not less than 300mm.

[0047] The bottom end of the spiral wound pipe 4 is inserted into the masonry layer 5 to a depth of not less than 300mm to ensure effective bonding between the pipe and the filter layer. This embedded design prevents the bottom of the spiral wound pipe 4 from being suspended, thus preventing groundwater from flowing around the bottom of the pipe. It enhances the collaborative working ability between the spiral wound pipe 4 and the masonry layer 5, improving drainage efficiency. At the same time, it prevents siltation at the bottom of the pipe, extending the service life of the spiral wound pipe 4.

[0048] Furthermore, such as Figure 1As shown, the spiral pipe 4 is a permeable pipe with an outer diameter of 1200-1400mm, and the pipe wall is provided with evenly distributed permeable holes for slope drainage.

[0049] The spiral wound pipe 4 is made of permeable material with an outer diameter of 1200-1400mm, and its wall has evenly distributed permeable holes. The large diameter design provides sufficient cross-sectional area for water flow, reducing flow resistance; the evenly distributed permeable holes ensure that groundwater can enter the pipe from all directions around its perimeter. The combination of large diameter and dense permeable holes significantly enhances the water collection capacity of the spiral wound pipe 4, accelerating groundwater drainage. Uniform permeability prevents localized blockages, ensuring the long-term stable operation of the drainage system.

[0050] The caisson structure of this utility model, applicable to dynamic soft rock slopes, is constructed by first selecting a location at the bottom of the slope and then manually excavating sections 1 meter high from top to bottom. Immediately after each section is excavated, a cast-in-place reinforced concrete retaining wall 1 is constructed. The internal steel reinforcement frame 11 and the external concrete layer 12 are poured together, utilizing the tensile strength of the steel reinforcement and the compressive strength of the concrete to form a robust cylindrical structure, providing foundation support for the caisson and preventing the collapse of the pile hole wall.

[0051] After the caisson is excavated to the designed depth, a top ring 2 is installed on top of the retaining wall 1. The top ring 2 is constructed of clay bricks and plastered with an M7.5 cement mortar layer on the outside, extending 1.2 meters above the ground. This serves to prevent erosion and enhance the structural strength of the caisson opening. At the bottom opening of the retaining wall 1, a masonry layer 5 is formed by dry-laying a mixture of 15-30mm small pebbles and 20-30mm large pebbles. This layer serves as the bottom support structure, distributing the caisson's self-weight and external loads. Simultaneously, drainage sleeves 6 are installed in a ring at 1000mm intervals in the middle of the retaining wall 1. One end extends to the outside of the retaining wall 1 to contact the slope soil and rock, while the other end is located on the inside of the retaining wall 1, preparing for groundwater diversion.

[0052] A spiral pipe 4 with an outer diameter of 1200-1400mm is placed inside the inner wall 1 of the caisson, with its bottom end inserted into the masonry layer 5 to a depth of not less than 300mm, and connected to the permeable structure of the masonry layer 5. The spiral pipe 4 has evenly distributed permeable holes on its wall to collect surrounding groundwater. Finally, a well cover 3 is installed on top of the top ring 2, and a water pump bracket 7 is placed on the well cover 3 to complete the caisson structure construction.

[0053] After being put into use, the cylindrical retaining wall 1, with its circular cross-section and uniform stress distribution, effectively disperses the lateral pressure from the dynamic soft rock slope. When uneven settlement or deformation occurs on the slope, in the reinforced concrete retaining wall 1, the steel frame 11 bears the tensile force, and the concrete layer 12 bears the compressive force. The two work together to resist deformation and ensure the stability of the caisson structure. The top ring 2 at the top prevents surface runoff from scouring the wellhead, and the masonry layer 5 at the bottom disperses the caisson's self-weight and external loads, preventing excessive disturbance of the bottom soil and further enhancing overall stability.

[0054] Under water pressure, groundwater within the slope seeps into the pipe through one end of the drainage sleeve 6, which is in contact with the slope's rock and soil. Utilizing gravity, it flows along the sleeve towards the inner side of the retaining wall 1 and enters the caisson. Simultaneously, the permeable holes in the wall of the winding pipe 4 collect the surrounding groundwater. Since its bottom end is connected to the masonry layer 5, the groundwater also flows into the caisson through the permeable structure of the masonry layer 5.

[0055] When the water in the caisson reaches a certain level, a water pump is installed on the water pump bracket 7. The water is pumped out of the caisson and discharged to a designated area, thereby reducing the pore water pressure in the slope and preventing the soft rock from weakening due to long-term immersion in water, thus achieving effective protection for the dynamic slope of soft rock.

[0056] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A caisson structure suitable for dynamic slopes in soft rock, comprising a retaining wall (1), characterized in that: The protective wall (1) adopts a cylindrical structure with openings at the top and bottom. A top ring (2) is installed on the top of the protective wall (1), a masonry layer (5) is installed at the bottom opening of the protective wall (1), a winding pipe (4) is provided on the inner side of the protective wall (1), a well cover (3) is installed on the top of the top ring (2), and a water pump bracket (7) is placed on the well cover (3).

2. The caisson structure suitable for dynamic slopes of soft rock according to claim 1, characterized in that: A plurality of hydrophobic sleeves (6) are installed in the middle of the protective wall (1). The hydrophobic sleeves (6) are arranged in a ring at equal intervals along the inner wall of the protective wall (1), with a spacing of 1000mm.

3. The caisson structure suitable for dynamic slopes of soft rock according to claim 2, characterized in that: The hydrophobic sleeve (6) is made of metal or hard plastic, with one end extending to the outside of the protective wall (1) and the other end located inside the protective wall (1).

4. The caisson structure suitable for dynamic slopes of soft rock according to claim 1, characterized in that: The top ring (2) is 1.2 meters above the ground, supported by clay bricks, and coated with an M7.5 cement mortar layer on the outside.

5. The caisson structure suitable for dynamic slopes of soft rock according to claim 1, characterized in that: The retaining wall (1) includes a steel reinforcement frame (11), and a concrete layer (12) is poured on the outside of the steel reinforcement frame (11).

6. The caisson structure suitable for dynamic slopes of soft rock according to claim 1, characterized in that: The masonry layer is formed by dry-laying a mixture of small pebbles (15-30mm) and large pebbles (20-30mm).

7. The caisson structure suitable for dynamic slopes of soft rock according to claim 1, characterized in that: The bottom end of the winding tube (4) is inserted into the masonry layer (5), and the depth of insertion into the masonry layer (5) is not less than 300mm.

8. The caisson structure suitable for dynamic slopes of soft rock according to claim 1, characterized in that: The spiral pipe (4) is a permeable pipe with an outer diameter of 1200-1400mm and has evenly distributed permeable holes on the pipe wall for slope drainage.

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