Underground structure of island reef

Abstract

The invention relates to the technical field of underground structures, and discloses an island underground structure which comprises a cavern, the cavern comprises a plurality of pipe joints which are sequentially connected in the extending direction of the cavern, each pipe joint comprises a top plate, a bottom plate and two side plates, the top plates and the bottom plates are oppositely arranged up and down, the two side plates are oppositely arranged left and right, the top ends of the side plates are connected with the top plates, and the bottom ends of the side plates are connected with the bottom plates. The top plate, the bottom plate and the side plates are each internally provided with a shock insulation cavity, and the shock insulation cavities are filled with polyurethane high polymers. According to the island underground structure, transmission of accidental loads such as explosion and earthquake to the interior of the cavern can be reduced, and the influence of earthquake loads, explosion loads and the like on the internal structure of the cavern is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of underground structures, and in particular to an island reef underground structure. Background Art

[0002] With the increasing demand for utility services, the available space on the ground is constantly decreasing. The development of underground space has become a solution for lifeline planning, and the construction of underground cavern structures is one of the important forms of development and utilization of underground space on islands and reefs. The underground structures of islands and reefs are large in scale and exposed, generally shallow in depth and highly vulnerable, and contain municipal pipelines, etc. The permanent loads borne by the cavern structure are soil pressure, the deadweight of the main structure and the built-in pipelines; the variable loads are ground vehicle loads and crowd loads; and the accidental loads are earthquakes, gas explosions and other loads. The existing cavern structure has poor ability to withstand earthquakes and explosion loads, which makes it difficult for the cavern structure to withstand precision-guided weapons. Once the key parts and weak parts suffer fatal blows, it will cause large-scale damage, serious damage to the internal pipelines, and loss of transmission function. The damage to the existing cavern structure under the action of earthquakes and explosion loads is specifically manifested as: the top of the structure is in an asymmetric bending shear failure mode, large-scale concrete spalling damage occurs on the inner wall side of the back explosion surface of the roof, concrete tensile damage occurs on the inner wall side of the front explosion surface, and there is a large residual slip between the central segment and the two adjacent segments. At the same time, the heat energy generated by the explosion load accumulates on the structure, causing damage to the internal pipelines of the structure, leading to gas explosions, etc.

[0003] Therefore, there is an urgent need for an island and reef underground structure to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide an island reef underground structure, which reduces the transmission of accidental loads such as explosions and earthquakes to the interior of the cave, and effectively reduces the impact of earthquakes, explosion loads, etc. on the internal structure of the cave.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] An island reef underground structure, comprising a cavern, the cavern comprising a plurality of pipe sections connected in sequence along the extending direction of the cavern, the pipe sections comprising a top plate, a bottom plate and two side plates, the top plate and the bottom plate are arranged opposite to each other up and down, the two side plates are arranged opposite to each other left and right, the top ends of the side plates are connected to the top plate, and the bottom ends are connected to the bottom plate;

[0007] The top plate, the bottom plate and the side plates are each provided with a seismic isolation cavity, and the seismic isolation cavity is filled with polyurethane polymer.

[0008] As an improvement of the above technical solution, the seismic isolation cavity in the top plate is a first seismic isolation cavity, the top plate includes an upper cover plate and an upper connecting plate, the top end of the upper connecting plate is provided with a first groove, the upper cover plate is covered on the top end of the upper connecting plate, and the upper cover plate closes the top end of the first groove to form the first seismic isolation cavity.

[0009] As an improvement of the above technical solution, the seismic isolation cavity in the base plate is a second seismic isolation cavity, the base plate includes a lower cover plate and a lower connecting plate, the bottom end of the lower connecting plate is provided with a second groove, the lower cover plate is covered on the bottom end of the lower connecting plate, and the lower cover plate closes the bottom end of the second groove to form the second seismic isolation cavity.

[0010] As an improvement of the above technical solution, the seismic isolation cavity in the side panel is a third seismic isolation cavity, the side panel includes a first splicing piece and a second splicing piece, the first splicing piece and the second splicing piece both extend along the height direction of the side panel, a third groove is provided on the side of the first splicing piece facing the second splicing piece, the second splicing piece and the first splicing piece are spliced ​​together to block the third groove to form the third seismic isolation cavity.

[0011] As an improvement of the above technical solution, a plurality of support columns are arranged at intervals in the first seismic isolation cavity, the second seismic isolation cavity and the third seismic isolation cavity. The support column in the first seismic isolation cavity penetrates the first seismic isolation cavity along the thickness direction of the first seismic isolation cavity, the support column in the second seismic isolation cavity penetrates the second seismic isolation cavity along the thickness direction of the second seismic isolation cavity, and the support column in the third seismic isolation cavity penetrates the third seismic isolation cavity along the thickness direction of the third seismic isolation cavity.

[0012] As an improvement of the above technical solution, both ends of the second splicing piece in the height direction are provided with plug-in protrusions, and both ends of the first height direction are provided with plug-in grooves, the plug-in grooves are arranged in one-to-one correspondence with the plug-in protrusions, and the plug-in protrusions are plugged into the corresponding plug-in grooves.

[0013] As an improvement of the above technical solution, the top plate, the bottom plate and the side plates are all provided with exhaust pipes and grouting pipes connecting the seismic isolation cavity with the inner side of the cavern.

[0014] As an improvement of the above technical solution, the pipe joint further includes a first connecting piece, a first connecting portion corresponding to the side plate is provided on a side of the upper connecting plate away from the upper cover plate, a first connecting portion is provided on an end of the first connecting portion away from the upper cover plate, a first connecting groove is provided, the top of the side plate is inserted into the first connecting groove on the corresponding first connecting portion, and the top of the side plate is connected to the first connecting portion via the first connecting piece;

[0015] A second connecting portion corresponding to the side plate is provided on the side of the lower connecting plate away from the lower cover plate, and a second connecting groove is provided on the side of the second connecting portion away from the lower cover plate. The lower portion of the side plate is inserted into the second connecting groove on the corresponding second connecting portion, and the lower portion of the side plate is connected to the second connecting portion via the first connecting piece.

[0016] As an improvement of the above technical solution, it also includes a circular vertical shaft, the bottom end of which is connected to the cavern, and the top end extends to the ground. The circular vertical shaft includes a plurality of circular pipe segments connected in sequence along the vertical direction, and each of the circular pipe segments is provided with a fourth seismic isolation cavity, and the fourth seismic isolation cavity is filled with the polyurethane polymer.

[0017] As an improvement of the above technical solution, it also includes a square vertical shaft, the bottom end of which is connected to the cavern, and the top end extends to the ground. The square vertical shaft includes a plurality of square pipe segments connected in sequence along the vertical direction, and each of the square pipe segments is provided with a fifth seismic isolation cavity, and the fifth seismic isolation cavity is filled with the polyurethane polymer.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The island and reef underground structure of the present invention has seismic isolation cavities arranged in the top plate, the bottom plate and the two side plates, and the seismic isolation cavities are filled with polyurethane polymers. The polyurethane polymers have excellent properties of non-water reaction, light weight and early strength, good ductility, suitable strength and adjustable material density during the filling process. By filling the seismic isolation cavity with polyurethane polymers, the seismic isolation cavity and the polyurethane polymers therein play the role of seismic isolation and heat insulation, reducing the transmission of accidental loads such as explosions and earthquakes to the interior of the cavern, and effectively reducing the influence of earthquakes, explosion loads, etc. on the internal structure of the cavern. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of an island and reef underground structure provided by an embodiment of the present invention;

[0021] Figure 2 is a cross-sectional view of a cavern of an island reef underground structure provided by an embodiment of the present invention;

[0022] Figure 3 It is a schematic diagram of the interior of a pipe segment of an island and reef underground structure provided by an embodiment of the present invention;

[0023] Figure 4 is a top view of an upper connecting plate of an island and reef underground structure provided by an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of a circular pipe section of an underground structure of an island or reef provided by an embodiment of the present invention being filled with a polyurethane polymer;

[0025] Figure 6 It is a schematic diagram of a circular pipe section of an underground structure of an island or reef provided by an embodiment of the present invention after a circular cover plate is removed after being filled with polyurethane polymer;

[0026] Figure 7 is a partial cross-sectional view of a circular pipe segment of an island and reef underground structure provided by an embodiment of the present invention;

[0027] Figure 8 is a partial cross-sectional view of a circular pipe segment of an island and reef underground structure provided by an embodiment of the present invention;

[0028] Fig. 9 It is a schematic diagram of a square pipe section of an underground structure of an island or reef provided by an embodiment of the present invention after being filled with polyurethane polymer and a square cover plate is removed;

[0029] Fig.10 is a partial cross-sectional view of a square pipe section of an island and reef underground structure provided by an embodiment of the present invention;

[0030] Fig.11 It is a schematic diagram of performing stress and deformation analysis on a pipe segment of an underground structure of an island or reef provided by an embodiment of the present invention at a length of dx.

[0031] In the figure:

[0032] 1. Cavern;

[0033] 11. Tube joint;

[0034] 111, top plate; 1111, upper cover plate; 1112, upper connecting plate; 11121, first connecting portion; 11122, first groove;

[0035] 112, bottom plate; 1121, lower cover plate; 1122, lower connecting plate; 11221, second connecting portion;

[0036] 113, side panel; 1131, first assembling piece; 1132, second assembling piece; 11321, plug-in protrusion;

[0037] 114. A first connecting member;

[0038] 12. A second connecting member;

[0039] 2. circular shaft; 21. circular pipe section; 211. inner annular concrete layer; 212. outer annular concrete layer;

[0040] 3. Square shaft; 31. Square pipe section; 311. Inner square concrete layer; 312. Outer square concrete layer;

[0041] 4. Round cover; 5. Square cover;

[0042] 10. Exhaust pipe; 20. Grouting pipe;

[0043] 100. Polyurethane polymer; 200. Support column. DETAILED DESCRIPTION

[0044] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0045] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0047] In the description of this embodiment, the terms "upper", "lower", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0048] The present embodiment provides an underground structure for islands and reefs. The underground structure for islands and reefs in the present embodiment is a prefabricated structure. Under the premise of ensuring the integrity and continuity of the structural system, the shear resistance of the connection parts is improved to improve the safety of the structure. Rigid connection is selected for all joint connection methods at the connection parts. Three measures can be introduced to determine the optimal position of the joint: the first is to place the joint in a place where the force on the complete structure is least affected; the second is to place it in a position that is most beneficial to the endurance of the overall structure; the third is to consider the convenience of the device during construction. Generally, the joint is set at a position where the bending moment is zero, which is in accordance with the principle of reducing the internal force consumption at the joint.

[0049] At the same time, the integrity of the structural system must be ensured, which is the key to the prefabricated structure design. For this reason, the prefabricated structure must strictly comply with the design requirements for reducing the connection between prefabricated parts, improving the discontinuous continuity of the connection parts, and ensuring the integrity of the structural system in the greatest sense, so that it can maximize its redundancy as much as possible, because the hyperstatic structure has higher, stronger and better seismic resistance and safety than the statically determinate structure. Therefore, the prefabricated structure design of the island and reef underground structure in this embodiment should also follow the following basic design principles:

[0050] ① Prefabricated structures are used in building facilities with regular and symmetrical planes and uniform vertical hardness.

[0051] ② The rigid nodes of prefabricated integral energy frames should meet the design requirements of cast-in-place structures, and their node bearing capacity and ductility should be higher than those of cast-in-place structures.

[0052] ③ The connection of prefabricated structures should ensure the continuity and integrity of the components to the greatest extent possible.

[0053] ④ The bearing capacity of the component connection point should be higher than the component it connects.

[0054] ⑤ Prefabricated integral joints should maximize the requirements of bearing capacity, stability and deformation during the construction process and use process.

[0055] ⑥ For rigid joints subject to bending moments, the cross-sectional stiffness of the joints should be designed to be similar to the stiffness of adjacent prefabricated components to avoid the consequences of stress concentration.

[0056] ⑦ Under the premise of meeting the requirements of overall force bearing capacity, the pursuit of simplicity in connection style and simplicity in force transmission should be maximized, and efforts should be made to ensure direct force transmission and precise force bearing.

[0057] ⑧ The design of the prefabricated structure should seek to simplify the installation, make the error easy to adjust, and after connection, be able to bear the load as soon as possible to facilitate the further construction of the superstructure.

[0058] Based on the above design ideas, Figure 1-Figure 4As shown, the underground structure of the island reef in this embodiment includes a cavern 1, which includes a plurality of pipe sections 11 connected in sequence along the extension direction of the cavern 1. The pipe section 11 includes a top plate 111, a bottom plate 112 and two side plates 113. The top plate 111 and the bottom plate 112 are arranged opposite to each other up and down, and the two side plates 113 are arranged opposite to each other left and right. The top end of the side plate 113 is connected to the top plate 111, and the bottom end is connected to the bottom plate 112. A seismic isolation cavity is arranged in the top plate 111, the bottom plate 112 and the side plate 113, and the seismic isolation cavity is filled with a polyurethane polymer 100.

[0059] The island and reef underground structure provided in the present embodiment has seismic isolation cavities arranged in the top plate 111, the bottom plate 112 and the two side plates 113, and the seismic isolation cavities are filled with polyurethane polymer 100. By filling the seismic isolation cavity with polyurethane polymer 100, the seismic isolation cavity and the polyurethane polymer 100 therein play the role of seismic isolation and heat insulation, reducing the transmission of accidental loads such as explosions and earthquakes to the interior of the cavern 1, and effectively reducing the impact of seismic loads, explosion loads, etc. on the internal structure of the cavern 1.

[0060] The polyurethane polymer 100 has excellent characteristics of non-water reaction, light weight, early strength, good ductility, suitable strength and adjustable material density during the filling process. After the polyurethane polymer 100 is filled in each shock-absorbing cavity of the pipe segment 11, the maximum principal stress, minimum principal stress and plastic zone area of ​​the structure can be effectively reduced, indicating that the polyurethane polymer 100 has a good shock-absorbing effect. In addition, the polyurethane polymer 100 has good heat insulation and anti-seepage properties, and can effectively block the heat energy generated by the explosion load.

[0061] Alternatively, if Figure 3 and Figure 4 As shown, the seismic isolation cavity in the top plate 111 is the first seismic isolation cavity. The top plate 111 includes an upper cover plate 1111 and an upper connecting plate 1112. The top end of the upper connecting plate 1112 is provided with a first groove 11122. The upper cover plate 1111 is covered on the top end of the upper connecting plate 1112. The upper cover plate 1111 closes the top end of the first groove 11122 to form a first seismic isolation cavity.

[0062] Furthermore, if Figure 3 and Figure 4 As shown, a plurality of support columns 200 are arranged at intervals in the first seismic isolation cavity. The support columns 200 in the first seismic isolation cavity penetrate the first seismic isolation cavity along the thickness direction of the first seismic isolation cavity. Each support column 200 in the first seismic isolation cavity plays a role in supporting the first seismic isolation cavity, so as to avoid excessive decrease in the structural strength of the top plate 111 due to the setting of the seismic isolation cavity. In this embodiment, the support columns 200 in the first seismic isolation cavity and the upper connecting plate 1112 are an integrated structure, and one end of the support column 200 in the first seismic isolation cavity close to the upper cover plate 1111 abuts against the upper cover plate 1111.

[0063] Alternatively, if Figure 3As shown, the seismic isolation cavity in the bottom plate 112 is the second seismic isolation cavity, the bottom plate 112 includes a lower cover plate 1121 and a lower connecting plate 1122, the bottom end of the lower connecting plate 1122 is provided with a second groove, the lower cover plate 1121 is covered on the bottom end of the lower connecting plate 1122, and the lower cover plate 1121 closes the bottom end of the second groove to form a second seismic isolation cavity. In this embodiment, the pipe section 11 also includes a first connecting member 114, a splicing protrusion is provided on the upper cover plate 1111, a splicing groove is provided on the upper connecting plate 1112, the splicing protrusion on the upper cover plate 1111 extends into the splicing groove on the upper connecting plate 1112, the upper cover plate 1111 and the upper connecting plate 1112 are connected by the first connecting member 114, specifically, the first connecting member 114 passes through the splicing protrusion on the upper cover plate 1111 and extends into the upper connecting plate 1112 to connect the upper cover plate 1111 and the upper connecting plate 1112. In this embodiment, the first connecting member 114 is a bolt.

[0064] Furthermore, if Figure 3 As shown, a plurality of support columns 200 are arranged at intervals in the second seismic isolation cavity. The support columns 200 in the second seismic isolation cavity penetrate the second seismic isolation cavity along the thickness direction of the second seismic isolation cavity. Each support column 200 in the second seismic isolation cavity plays a role in supporting the second seismic isolation cavity, so as to avoid excessive decrease in the structural strength of the bottom plate 112 due to the setting of the seismic isolation cavity. In this embodiment, the support columns 200 in the second seismic isolation cavity and the lower connecting plate 1122 are an integrated structure, and one end of the support column 200 in the second seismic isolation cavity close to the lower cover plate 1121 abuts against the lower cover plate 1121.

[0065] Alternatively, if Figure 3 As shown, the seismic isolation cavity in the side panel 113 is the third seismic isolation cavity. The side panel 113 includes a first splicing piece 1131 and a second splicing piece 1132. The first splicing piece 1131 and the second splicing piece 1132 both extend along the height direction of the side panel 113. A third groove is provided on the side of the first splicing piece 1131 facing the second splicing piece 1132. The second splicing piece 1132 and the first splicing piece 1131 are spliced ​​to block the third groove to form the third seismic isolation cavity.

[0066] Furthermore, if Figure 3 As shown, both ends of the second splicing piece 1132 in the height direction are provided with plug-in protrusions 11321, and both ends of the first height direction are provided with plug-in grooves, the plug-in grooves and the plug-in protrusions 11321 are arranged in a one-to-one correspondence, and the plug-in protrusions 11321 are plugged into the corresponding plug-in grooves.

[0067] Furthermore, if Figure 3As shown, a plurality of support columns 200 are arranged at intervals in the third seismic isolation cavity. The support columns 200 in the third seismic isolation cavity penetrate the third seismic isolation cavity along the thickness direction of the third seismic isolation cavity. Each support column 200 in the third seismic isolation cavity plays a role in supporting the third seismic isolation cavity, so as to avoid excessive decrease in the structural strength of the side plate 113 due to the setting of the seismic isolation cavity. In this embodiment, the support column 200 in the third seismic isolation cavity is an integrated structure with the first splicing piece 1131, and one end of the support column 200 close to the second splicing piece 1131 abuts against the second splicing piece 1132.

[0068] Alternatively, if Figure 3 As shown, the top plate 111, the bottom plate 112 and the side plate 113 are all provided with an exhaust pipe 10 and a grouting pipe 20 connecting the seismic isolation cavity with the inner side of the cavern 1. The grouting pipe 20 is used to fill the seismic isolation cavity with polyurethane polymer 100, and the air in the seismic isolation cavity is discharged through the exhaust pipe 10 during the filling process of the polyurethane polymer 100.

[0069] Alternatively, if Figure 3 As shown, a first connection portion 11121 corresponding to the side plate 113 is provided on the side of the upper connection plate 1112 away from the upper cover plate 1111, a first connection groove is provided on the end of the first connection portion 11121 away from the upper cover plate 1111, the top of the side plate 113 is inserted into the first connection groove on the corresponding first connection portion 11121, and the top of the side plate 113 is connected to the first connection portion 11121 via a first connection member 114. A second connection portion 11221 corresponding to the side plate 113 is provided on the side of the lower connection plate 1122 away from the lower cover plate 1121, a second connection groove is provided on the side of the second connection portion 11221 away from the lower cover plate 1121, the lower portion of the side plate 113 is inserted into the second connection groove on the corresponding second connection portion 11221, and the lower portion of the side plate 113 is connected to the second connection portion 11221 via a first connection member 114. A "mortise joint" is formed at the connection between the first connection part 11121 and the side plate 113 and between the second connection part 11221 and the side plate 113. The "mortise joint" is a new type of joint structure based on the mortise and groove connection, which fills the gap with grout to bridge the joint and enhance the reliability and anti-deformation ability of the connection. The assembled underground structure and joint have typical eccentric compression properties. Under the combined action of bending moment and axial force, the mechanical properties and bearing capacity of the joint are closely related to the stress level of the structure and present a certain degree of complexity.

[0070] Alternatively, if Figure 2As shown, a deformation joint is set between two adjacent pipe sections 11, and the deformation joint is filled with a rubber waterstop and a polyethylene foam caulking plate. The stress deformation of the deformation joint mainly depends on the mechanical properties of the rubber waterstop inside it. The rubber waterstop is a hyperelastic material mainly composed of rubber, which exhibits highly nonlinear stress-strain behavior and is characterized by maintaining elasticity under extremely large strains. The two adjacent pipe sections 11 are connected by a second connecting piece 12. Specifically, a reinforcement hole is reserved in the pipe section 11. When the pipe section 11 is installed, the second connecting piece 12 is inserted into the pipe section 11. After tensioning and locking, the pipe section 11 is connected in series to form an integral pipeline with a certain rigidity. The second connecting piece 12 can be made of high-strength steel bars or bolts. In this embodiment, the second connecting piece 12 is a bolt. Bolt connection has the advantages of short reserved channels, convenient installation, simple process, and fast construction speed. The connection between two adjacent pipe sections 11 relies on a joint composed of a rubber waterstop and a second connecting piece 12, which ensures the stability and waterproofness between the two pipe sections 11. Therefore, the cavern 1 is a composite structure formed by reinforced concrete pipe sections 11 and joints. Due to the existence of the joint, its stiffness, especially shear stiffness, is greatly weakened compared to the complete concrete structure.

[0071] Alternatively, if Figure 1 , Figure 5 , Figure 6 and Figure 7 As shown, the underground structure of the island reef also includes a circular shaft 2, the bottom end of the circular shaft 2 is connected to the cavern 1, the top end extends to the ground, the inner cavity of the circular shaft 2 is connected to the inner cavity of the cavern 1, and the circular shaft 2 includes a plurality of circular pipe segments 21 connected in sequence along the vertical direction, each circular pipe segment 21 is provided with a fourth seismic isolation cavity, and the fourth seismic isolation cavity is filled with polyurethane polymer 100. By providing the fourth seismic isolation cavity in the circular pipe segment 21 and filling the fourth seismic isolation cavity with polyurethane polymer 100, the damage to the circular shaft 2 caused by accidental loads such as earthquakes and explosions can be reduced. The circular pipe segment 21 includes an inner annular concrete layer 211 and an outer annular concrete layer 212, the inner annular concrete layer 211 is arranged in the outer square concrete layer 312, and the inner annular concrete layer 211 and the outer annular concrete layer 212 are arranged at intervals so that a fourth seismic isolation cavity is formed between the inner annular concrete layer 211 and the outer annular concrete layer 212.

[0072] Furthermore, if Figure 1 , Figure 8 , Fig. 9 and Fig.10As shown, the underground structure of the island reef also includes a square shaft 3, the bottom end of the square shaft 3 is connected to the cavern 1, and the top end extends to the ground. The square shaft 3 includes a plurality of square pipe segments 31 connected in sequence along the vertical direction, and each square pipe segment 31 is provided with a fifth seismic isolation cavity, and the fifth seismic isolation cavity is filled with polyurethane polymer 100. By providing the fifth seismic isolation cavity in each square pipe segment 31 and filling the fifth seismic isolation cavity with polyurethane polymer 100, the damage to the square shaft 3 caused by accidental loads such as earthquakes and explosions can be reduced. The square pipe segment 31 includes an inner square concrete layer 311 and an outer square concrete layer 312, the inner square concrete layer 311 is arranged in the outer square concrete layer 312, and the inner square concrete layer 311 and the outer square concrete layer 312 are arranged at intervals, so that the fifth seismic isolation cavity is formed between the inner square concrete layer 311 and the outer square concrete layer 312.

[0073] Furthermore, if Figure 1 As shown, deformation joints are provided between two adjacent circular pipe sections 21 and between two adjacent square pipe sections 31, and the deformation joints are filled with rubber water stop strips and polyethylene foam caulking plates.

[0074] The circular vertical shaft 2 and the square vertical shaft 3 are used for transporting objects between the cavern 1 and the ground. Providing two vertical shafts of different shapes is beneficial to the transport of objects of different shapes.

[0075] The vertical shaft is an important project to gain space underground, and it plays an irreplaceable role in the development and utilization of underground space. The underground shaft group structure is easily damaged by various external factors - affected by the shock wave of air explosion, affected by the natural vibration characteristics of the structure and the vibration characteristics of the soil during an earthquake, etc. Therefore, it is necessary to design earthquake-resistant and explosion-proof measures for the underground shaft group structure. In this embodiment, a circular shaft 2 and a square shaft 3 are designed above the cavern 1. The shaft structure is designed with a seismic isolation belt formed by a polyurethane polymer 100. At the same time, a deformation joint is set at a certain distance in the structure, and the deformation joint joint is filled with a rubber water stop and a polyethylene foam caulking plate to ensure the integrity and stability of the shaft.

[0076] The shaft structure (including the circular shaft 2 and the square shaft 3) in this embodiment is cast in situ, with a designed mold and cast in sections from bottom to top. Figure 5 , Figure 6 , Figure 8 and Fig. 9As shown, during the pouring process of each pipe section, steel bars are placed first, and concrete is poured on both sides of the seismic isolation cavity (the fourth seismic isolation cavity or the fifth seismic isolation cavity), and a top cover is installed on the poured concrete (the circular pipe section 21 is covered with a circular cover plate 4, and the square pipe section 31 is covered with a square cover plate 5). The top cover reserves a grouting pipe 20 and an exhaust pipe 10, and the top cover is connected to the poured concrete by bolts, so that during the process of injecting polymer into the pipe section through the grouting pipe 20, the top cover and the poured concrete structure remain in close contact, thereby ensuring the successful grouting of the polymer. After the polymer in the pipe section is filled, the top cover is removed, and the pouring and polymer injection of the adjacent pipe section of the pipe section are carried out.

[0077] The longitudinal deformation differential equation of the structure of the cavern provided in this embodiment is derived as follows:

[0078] The structure is analyzed theoretically, and the derivation of the theoretical model is based on the following basic assumptions and simplifications:

[0079] The interaction between the structure and the surrounding soil along its axial direction is simplified to the Winkler foundation model, and the soil layer is approximately regarded as an elastic foundation.

[0080] ②The Winkler foundation coefficient k changes along the structural axis with the moisture content of the foundation;

[0081] ③ The bottom plate always keeps in contact with the bottom soil, that is, the deformation of the structure and the soil is equal;

[0082] ④Simplify the structure into a Timoshenko beam model;

[0083] The nth section structure is simplified as a beam on a Winkler elastic foundation. The Winkler hypothesis states that the settlement y at any point on the foundation surface is n (x) and the load intensity p at the force application point n (x), that is:

[0084] p n (x) = BK(x)y n (x)

[0085] Where: K(x) - variable stiffness coefficient of foundation;

[0086] B - Structural foundation width

[0087] The magnitude of the foundation reaction coefficient of the soil is not only related to the state of the soil itself, but also affected by the stiffness of the beam. Attewell proposed an expression for the foundation bed coefficient of a foundation beam buried at a certain depth, taking into account the beam stiffness and stratum characteristics:

[0088]

[0089] Where: Ei is the elastic modulus of soil, v s is the Poisson's ratio of soil.

[0090] The interaction between the tunnel foundation and the soil is determined by the local elastic deformation method. Fig.11 As shown, take a unit of length dx to analyze the force and deformation. From the vertical force balance of the microelement, the bending moment of any section of the foundation at any point x from the left end of the structural foundation can be obtained as:

[0091]

[0092] The shear and load strengths at the above sections are:

[0093]

[0094] Where: M is the bending moment caused by the overlying uniformly distributed load q0;

[0095] M(x) - bending moment of any section at a distance x from the left end of the tunnel;

[0096] Q(x) - the shear force generated by the uniformly distributed load q0 at a distance x from the left end of the tunnel;

[0097] η – Settlement at a distance ξ from the left end of the corridor.

[0098] Then the deflection equation of the pipe gallery is:

[0099]

[0100] Thus, the bending differential equation of the nth tunnel section based on the local elastic deformation model is obtained:

[0101]

[0102] The analytical solution of the elastic foundation beam under concentrated force is shown below:

[0103]

[0104] Where: λ is a comprehensive parameter related to the elastic properties of the beam and foundation.

[0105]

[0106] K - variable stiffness coefficient of foundation;

[0107] B - structural beam foundation width;

[0108] p i - Concentrated forces acting on the structure.

[0109] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. An underground structure of an island or reef, characterized in that: The invention comprises a cavern (1), wherein the cavern (1) comprises a plurality of pipe sections (11) connected in sequence along the extension direction of the cavern (1), wherein the pipe section (11) comprises a top plate (111), a bottom plate (112) and two side plates (113), wherein the top plate (111) and the bottom plate (112) are arranged opposite to each other vertically, and the two side plates (113) are arranged opposite to each other horizontally, and the top end of the side plate (113) is connected to the top plate (111), and the bottom end is connected to the bottom plate (112); The top plate (111), the bottom plate (112) and the side plate (113) are each provided with a seismic isolation cavity, and the seismic isolation cavity is filled with a polyurethane polymer (100).

2. The island and reef underground structure according to claim 1, characterized in that: The seismic isolation cavity in the top plate (111) is a first seismic isolation cavity. The top plate (111) comprises an upper cover plate (1111) and an upper connecting plate (1112). A first groove (11122) is arranged at the top end of the upper connecting plate (1112). The upper cover plate (1111) is covered on the top end of the upper connecting plate (1112). The upper cover plate (1111) closes the top end of the first groove (11122) to form the first seismic isolation cavity.

3. The island and reef underground structure according to claim 2, characterized in that: The seismic isolation cavity in the base plate (112) is a second seismic isolation cavity. The base plate (112) comprises a lower cover plate (1121) and a lower connecting plate (1122). A second groove is arranged at the bottom end of the lower connecting plate (1122). The lower cover plate (1121) is covered on the bottom end of the lower connecting plate (1122). The lower cover plate (1121) closes the bottom end of the second groove to form the second seismic isolation cavity.

4. The island and reef underground structure according to claim 3, characterized in that: The seismic isolation cavity in the side plate (113) is a third seismic isolation cavity. The side plate (113) comprises a first splicing piece (1131) and a second splicing piece (1132). The first splicing piece (1131) and the second splicing piece (1132) both extend along the height direction of the side plate (113). A third groove is arranged on one side of the first splicing piece (1131) facing the second splicing piece (1132). The second splicing piece (1132) and the first splicing piece (1131) are spliced ​​to block the third groove to form the third seismic isolation cavity.

5. The island and reef underground structure according to claim 4, characterized in that: A plurality of support columns (200) are arranged at intervals in the first seismic isolation cavity, the second seismic isolation cavity and the third seismic isolation cavity; the support columns (200) in the first seismic isolation cavity penetrate the first seismic isolation cavity along the thickness direction of the first seismic isolation cavity; the support columns (200) in the second seismic isolation cavity penetrate the second seismic isolation cavity along the thickness direction of the second seismic isolation cavity; and the support columns (200) in the third seismic isolation cavity penetrate the third seismic isolation cavity along the thickness direction of the third seismic isolation cavity.

6. The island and reef underground structure according to claim 4, characterized in that: Both ends of the second splicing piece (1132) in the height direction are provided with plug-in protrusions (11321), and both ends of the first height direction are provided with plug-in grooves, the plug-in grooves and the plug-in protrusions (11321) are arranged in a one-to-one correspondence, and the plug-in protrusions (11321) are plugged into the corresponding plug-in grooves.

7. The island and reef underground structure according to claim 4, characterized in that: The top plate (111), the bottom plate (112) and the side plate (113) are all provided with an exhaust pipe (10) and a grouting pipe (20) which connect the seismic isolation cavity with the inner side of the cavern (1).

8. The island and reef underground structure according to claim 3, characterized in that: The pipe joint (11) further comprises a first connecting member (114); a first connecting portion (11121) corresponding to the side plate (113) is provided on a side of the upper connecting plate (1112) away from the upper cover plate (1111); a first connecting groove is provided on an end of the first connecting portion (11121) away from the upper cover plate (1111); a top of the side plate (113) is inserted into the first connecting groove on the corresponding first connecting portion (11121); and the top of the side plate (113) and the first connecting portion (11121) are connected via the first connecting member (114); A second connecting portion (11221) corresponding to the side plate (113) is provided on the side of the lower connecting plate (1122) facing away from the lower cover plate (1121), and a second connecting groove is provided on the side of the second connecting portion (11221) away from the lower cover plate (1121), and the lower portion of the side plate (113) is inserted into the second connecting groove on the corresponding second connecting portion (11221), and the lower portion of the side plate (113) and the second connecting portion (11221) are connected via the first connecting member (114).

9. The island and reef underground structure according to claim 1, characterized in that: It also comprises a circular vertical shaft (2), the bottom end of the circular vertical shaft (2) being connected to the cavern (1), and the top end extending to the ground, the circular vertical shaft (2) comprising a plurality of circular pipe segments (21) connected in sequence along a vertical direction, each of the circular pipe segments (21) being provided with a fourth seismic isolation cavity, and the fourth seismic isolation cavity being filled with the polyurethane polymer (100).

10. The island and reef underground structure according to claim 1, characterized in that: It also comprises a square vertical shaft (3), the bottom end of the square vertical shaft (3) is connected to the cavern (1), and the top end extends to the ground, the square vertical shaft (3) comprises a plurality of square pipe segments (31) connected in sequence along the vertical direction, each of the square pipe segments (31) is provided with a fifth seismic isolation cavity, and the fifth seismic isolation cavity is filled with the polyurethane polymer (100).

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