Basement structure construction method combining separate warehouse building and alternate warehouse dismantling
Through the use of sub -warehouse construction in the subway reserves and cultural relics reserves, the construction method of the basement structure combined with the binding position removal solves the problems of the construction cycle and hidden safety hazards caused by the traditional construction method, and realize the shortening of the construction cycle and the safety of construction safety Guarantee.
Patent Information
- Application Number
- CN202411635537.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-15
- Publication Date
- 2025-01-28
AI Technical Summary
When constructing the basement structure next to the subway protection zone and the cultural relics protection zone, the traditional foundation pit sub-warehouse construction method leads to a long construction cycle, affecting the safety of subway operation and the protection of historical buildings, and the temporary underground wall removal poses safety and quality hazards.
The construction method of the basement structure combined with the binding position -jump warehouse is adopted. By supporting the permanent underground ground on the periphery of the foundation pit, the wall is constructed temporarily on the inside of the foundation pit, and multiple groups of work steel is set on both sides. Support support. During construction, the base pits of each warehouse will be constructed in order in accordance with the long -distance and near order of the subway protection area and the cultural relics protection area, and after the construction of the basement of the base pit of the sub -warehouse, the steel truss expansion is used for deformation control. The temporary underground wall is used to use the jumping method when removal, from top to bottom, and dismantle, and during the dismantling process, the dispersion load is replaced and poured back.
This method effectively shortens the construction cycle, minimizing the impact on subway tunnels and cultural relic buildings, ensuring the safety and quality of construction, and avoiding hidden dangers of safety and quality in traditional methods.
Smart Images
Figure CN119373149A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of building construction, and in particular to a basement structure construction method combining compartment building and skip compartment demolition. Background Art
[0002] With the continuous development of subway transportation construction technology in my country, there are more and more urban subway tunnel construction projects. The increase in urban population has also made urban land resources increasingly tight, and the number of buildings built near operating subways will inevitably increase. The disturbance of the surrounding soil caused by foundation pit excavation will cause deformation of nearby subway tunnels. Combined with the characteristics of subway tunnel operation, it can be found that the factors causing tunnel deformation are relatively complex, including loading and unloading of adjacent subway tunnels, regional ground settlement, train vibration, changes in geological conditions, and crossing construction between tunnels. In order to minimize the impact of foundation pit excavation on tunnel deformation during foundation pit excavation, effective deformation control measures must be taken to protect the subway tunnel foundation pit excavation and ensure the smooth and safe operation of the original subway tunnel. When actually carrying out subway tunnel protection, it is necessary to combine the relative position of the foundation pit and the subway, the geological conditions of the excavation, and the specific characteristics of each project, and adopt an effective subway protection plan to ensure the feasibility and safety of the construction method.
[0003] When excavating a super-large deep foundation pit next to an operating subway tunnel, special attention should be paid to the horizontal displacement of the tunnel structure. If the foundation pit is excavated directly, the earth pressure balance on both sides of the subway tunnel will be destroyed, and the tunnel will inevitably produce a large horizontal displacement that does not meet the safety of subway operation. In this regard, according to the scope of influence of the foundation pit deformation, the method of dividing the super-large deep foundation pit into compartments is often used for excavation and construction. First, the foundation pit is separated by a partition wall and then constructed. The foundation pit far away from the subway side is constructed first to minimize the impact on the subway tunnel. In addition, combined with the location of the protected building, the compartments are further refined, and the construction sequence is determined according to the principle of far first and near later. After the ordinary foundation pit compartment construction, it is necessary to wait until the basement structure of the compartment foundation pit is fully constructed before the first earthwork excavation and internal support construction of the next compartment deep foundation pit can be carried out, which seriously restricts the overall construction period of the foundation pit, and the construction period is long, which is easy to affect the safety of buildings adjacent to the subway and historical style protection.
[0004] In actual construction, temporary underground ground-anchored walls are used to divide the foundation pit into compartments. After the construction of the basement structure in the foundation pit is completed, the temporary underground ground-anchored walls are dismantled. The traditional centralized demolition method has a relatively concentrated unloading method, which is prone to safety and quality hazards. In addition, the continuous pouring of ultra-long post-casting strips can easily lead to concrete cracks, affecting the quality of the project. Summary of the invention
[0005] The purpose of the present invention is to provide a basement structure construction method combining compartment building and compartment dismantling, which solves the construction problems encountered when constructing basement structures next to subway protection areas and cultural relics protection areas.
[0006] To achieve the above object, the present invention adopts the following technical solutions: A method for constructing a basement structure by combining compartment building and skip compartment demolition, including a subway protection zone and a cultural relic protection zone, excavating a foundation pit and constructing a basement structure on a side of the subway protection zone and a side adjacent to the cultural relic protection zone at zero distance, and the foundation pit is in a quadrilateral shape as a whole and avoids the subway protection zone and the cultural relic protection zone, including the following steps: Step 1: According to the protection scope of the subway protection zone and the cultural relics protection zone, a temporary underground ground-connected wall is set up to divide the interior of the foundation pit into compartments; Step 2: Support the permanent underground diaphragm wall outside the foundation pit, construct a temporary underground diaphragm wall inside the foundation pit to divide the foundation pit, and support the temporary underground diaphragm wall with multiple groups of I-beams on both sides, and the multiple I-beams are distributed in a matrix shape; Step 3: Excavate each sub-compartment foundation pit to the bottom elevation of the first internal support at the same time, and then complete the construction of the crown beam and the first internal support of each sub-compartment foundation pit; Step 4: The basement structures of the foundation pits of each compartment are constructed in the order from far to near the subway protection area and the cultural relics protection area; Step 5: After the construction of the basement structure of the compartment foundation pit is completed, the formwork is removed after the basement structure meets the structural strength and demolding conditions. After the formwork is removed, a steel truss interlayer is set in each compartment foundation pit; Step 6: Divide the temporary underground ground-connected wall into compartments, and remove the temporary underground ground-connected wall by compartments; When skipping warehouses for demolition, temporary underground diaphragm walls are demolished layer by layer from top to bottom. When a temporary underground diaphragm wall of a certain layer is demolished, multiple sets of I-beam supports on both sides of the temporary underground diaphragm wall of a certain warehouse are replaced first. After the replacement of supports is completed, the remaining walls of the temporary underground diaphragm wall of the warehouse are demolished. After the remaining walls are demolished, the second post-cast joint of the remaining area between the floor slabs of the basement structure of this layer of the adjacent sub-warehouse foundation pit is poured. Then, the temporary underground diaphragm walls of the next warehouse are demolished by skipping warehouses until all the temporary underground diaphragm walls of this layer are demolished, and then the temporary underground diaphragm walls of the next layer are demolished.
[0007] Preferably, in step one, the layout position and design parameters of the temporary underground ground-connected wall are determined based on the relative position relationship between the foundation pit and the subway protection area and between the foundation pit and the cultural relics protection area.
[0008] Preferably, the temporary underground ground connection wall is arranged in accordance with the principle of forming a regular polygon with the permanent underground ground connection wall, and the area of the regular polygon becomes larger the further away from the subway protection zone and the cultural relics protection zone.
[0009] Preferably, in the step 2, during the reinforcement binding process of the temporary underground ground-connected wall, a plurality of groups of I-beam braces are placed and fixed at corresponding positions and cast in one step.
[0010] Preferably, the I-beam brace includes two I-beams, which are correspondingly supported on both sides of the temporary underground ground-connected wall, with one end pre-buried in the side of the floor slab of the basement structure of the compartment foundation pit and the other end supported on the side of the temporary underground ground-connected wall.
[0011] Preferably, in step four, each sub-compartment foundation pit is first constructed in the order of earth excavation, internal support construction and foundation slab, and then each internal support is removed and the basement structure of the corresponding floor is constructed in a bottom-up order.
[0012] Preferably, in step six, the specific operation of replacing the support is to first demolish a small area of the floor slab of the basement structure of the compartment foundation pit at the position corresponding to the I-beam support, and then cast the first post-cast joint to realize the support replacement.
[0013] Preferably, in step six, after the pouring of the second post-casting strip of a basement structure on a certain floor is completed, the steel truss mezzanine of the basement structure on the next floor is removed, and then the temporary underground ground-connected wall is removed.
[0014] Preferably, temporary underground annular walls within 500mm of the subway protection zone and the cultural relics protection zone are demolished by a combination of static blasting and manual pneumatic picks; temporary underground annular walls in other areas are demolished by a combination of crushing guns and machinery.
[0015] In the present invention, when the foundation pit is excavated, the deformation of the pit wall soil can easily cause horizontal displacement of the subway tunnel structure or the foundation of the cultural relic building. Therefore, in the present invention, the foundation pit is divided into compartments using temporary underground ground-connected walls before the basement structure is constructed. After the foundation pit is divided into compartments, the construction is carried out in the order from far to near the subway protection zone or the cultural relic protection zone, so as to minimize the impact on the subway tunnel and the cultural relic building.
[0016] Compared with the conventional compartmentalized foundation pit construction, the compartmentalized foundation pits of the present invention can be excavated to the bottom elevation of the first internal support at the same time, and then the crown beam and the first internal support of each compartmentalized foundation pit can be completed. Then, the basement structure of each compartmentalized foundation pit is constructed in order from far to near in the order of distance from the subway protection zone or the cultural relics protection zone. After the construction of the basement structure of one of the compartmentalized foundation pits is completed, the steel truss interlayer technology is immediately used to control the deformation of the foundation pit, which not only effectively shortens the construction period, but also minimizes the impact of the engineering construction on the subway protection zone and the cultural relics protection zone.
[0017] The present invention adopts the skipping method to demolish the temporary underground ground-connected wall. During the skipping demolition, compared with the traditional method of demolishing the wall layer by layer from top to bottom, the present invention first demolishes a small area at the position corresponding to the floor slab and the I-beam support of the basement structure of the compartment foundation pit, and casts the first post-cast joint after the demolition to achieve support replacement. After the support replacement is completed, the remaining wall of the temporary underground ground-connected wall in the basement structure of each floor is demolished from top to bottom, and the second post-cast joint of the remaining area between the floor slabs of each compartment foundation pit is cast after the demolition, which disperses the load of the temporary underground ground-connected wall during the demolition process, effectively eliminates the safety hazards during the demolition process and ensures the safety of the construction personnel.
[0018] The second post-cast joint used for supporting replacement and the first post-cast joint cast in the remaining area between the floor slabs of each compartment foundation pit after the remaining walls of the temporary underground ground-connected wall are demolished together constitute the post-cast joint between the floor slabs of each floor, avoiding the problem of concrete cracks caused by continuous casting of excessively long post-cast joints between floor slabs, which in turn affects the quality of the project.
[0019] I-beam braces can be used in a circular manner, which has good economic benefits.
[0020] When dismantling temporary underground ground-connected walls, the principle of skipping and discontinuous demolition should be followed. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 It is a plan view of the foundation pit and surrounding environment of the present invention; Figure 2 The present invention is a schematic diagram of the construction process of dismantling the temporary underground ground-connected wall from top to bottom. Figure 1 ; Figure 3 This is a schematic diagram of a temporary underground ground-connected wall of a certain layer of the present invention being supported by I-beams; Figure 4 The schematic diagram of the construction process of the present invention is to remove a temporary underground ground-connected wall of a certain layer by skipping the warehouse Figure 1 ; Figure 5 The schematic diagram of the construction process of the present invention is to remove a temporary underground ground-connected wall of a certain layer by skipping the warehouse Figure 2 ; Figure 6The schematic diagram of the construction process of the present invention is to remove a temporary underground ground-connected wall of a certain layer by skipping the warehouse Figure 3 ; Figure 7 The schematic diagram of the construction process of the present invention is to remove a temporary underground ground-connected wall of a certain layer by skipping the warehouse Figure 4 ; Figure 8 The present invention is a schematic diagram of the construction process of dismantling the temporary underground ground-connected wall from top to bottom. Figure 2 ; Fig. 9 The present invention is a schematic diagram of the construction process of dismantling the temporary underground ground-connected wall from top to bottom. Figure 3 ; In the figure: 1. Subway protection zone; 2. Cultural relics protection zone; 3. Foundation pit; 4. Basement structure; 5. Temporary underground ground-connected wall; 6. Permanent underground ground-connected wall; 7. I-beam bracing; 8. First post-cast joint; 9. Second post-cast joint; 10. Steel truss layer; 11. Crown beam; 12. First internal support. DETAILED DESCRIPTION
[0022] The present invention will be further described below in conjunction with the accompanying drawings: like Figures 1 to 9 A basement structure construction method combining compartment building and skip compartment demolition is shown, including a subway protection area 1 and a cultural relic protection area 2, such as Figure 1 As shown, a foundation pit 3 is excavated and a basement structure 4 is constructed on the side of the subway protection zone 1 and the side of the cultural relics protection zone 2, and the foundation pit 3 is a quadrilateral as a whole and avoids the subway protection zone 1 and the cultural relics protection zone 2, including the following steps: Step 1: According to the protection scope of the subway protection zone 1 and the cultural relics protection zone 2, a temporary underground ground-connected wall 5 is set to design compartments inside the foundation pit 3; According to the relative position relationship between the foundation pit 3 and the subway protection area 1 and between the foundation pit 3 and the cultural relics protection area 2, the layout position and design parameters of the temporary underground ground-connected wall 5 are determined; The arrangement principle of the temporary underground ground connection wall 5 is to form a regular polygon with the permanent underground ground connection wall 6, and the area of the regular polygon is larger the farther away from the subway protection area 1 and the cultural relics protection area 2; Step 2: Support the permanent underground diaphragm wall 6 outside the foundation pit 3, construct the temporary underground diaphragm wall 5 inside the foundation pit 3 to divide the foundation pit 3, and pass multiple groups of I-beam braces 7 on both sides of the temporary underground diaphragm wall 5. The multiple I-beam braces 7 are distributed in a matrix shape. Specifically, during the reinforcement binding process of the temporary underground diaphragm wall 5, the multiple groups of I-beam braces 7 are placed and fixed at corresponding positions, and cast into shape at one time, thereby eliminating the disadvantages of the small space and difficult construction of the temporary underground diaphragm wall 5; The I-beam brace 7 includes two I-beams, which are supported on both sides of the temporary underground ground-connecting wall 5, one end of which is pre-buried in the floor slab side of the basement structure 4 of the compartment foundation pit 3, and the other end is supported on the side of the temporary underground ground-connecting wall 5; the length of the I-beam is not less than 1.5m, and the model is determined after calculation to be set at an interval of no more than 1.0m; a head plate is set at one end of the I-beam close to the temporary underground ground-connecting wall 5, and an end plate is set at one end anchored in the floor slab, the thickness of the head plate and the end plate is not less than 10mm, and the I-beam brace is anchored into the floor slab by no less than 500mm; Step 3: excavate each compartment foundation pit 3 to the bottom elevation of the first inner support at the same time, and then complete the construction of the crown beam and the first inner support 12 of each compartment foundation pit 3. To facilitate the construction work, the removal of the local shorter temporary underground ground-connected wall 5 can be carried out simultaneously with the earthwork excavation, changing the dark excavation to open excavation; Step 4: construct the basement structure 4 of each sub-compartment foundation pit 3 in the order of distance from the subway protection area 1 and the cultural relics protection area 2 from far to near; Each sub-compartment foundation pit 3 is first constructed in the order of earth excavation, internal support construction and foundation slab, and then each internal support is removed and the corresponding floor basement structure 4 is constructed in the order from bottom to top; Step 5: After the construction of the basement structure 4 of the compartment foundation pit 3 is completed, the template is removed after the basement structure 4 meets the structural strength and demolding conditions. After the template is removed, a steel truss interlayer 10 is set in each compartment foundation pit 3; Step 6: divide the temporary underground ground-connected wall 5 into compartments, and remove the temporary underground ground-connected wall 5 by skipping compartments; When the jump warehouse is removed, Figure 2 As shown, the temporary underground ground-connected wall 5 is dismantled layer by layer from top to bottom. Figure 3-4 When a temporary underground diaphragm wall 5 of a certain layer is to be demolished, the multiple groups of I-beam supports 7 on both sides of the temporary underground diaphragm wall 5 of a certain warehouse are first replaced, and after the replacement is completed, the remaining wall of the temporary underground diaphragm wall 5 of the warehouse is demolished. After the remaining wall is demolished, the second post-casting strip 9 of the remaining area between the corresponding floor slabs of the basement structure 4 of the adjacent sub-warehouse foundation pit 3 is poured, such as Figure 5 to Figure 7 As shown, then jump to the next warehouse to remove the temporary underground ground-connected wall 5 until all the temporary underground ground-connected walls 5 of this layer are removed. Figure 8 and Fig. 9 As shown, the next layer of temporary underground ground-connected wall 5 is removed; The specific operation of the support replacement is to first remove a small area of the floor slab of the basement structure 4 of the compartment foundation pit 3 corresponding to the position of the I-beam support 7, and then pour the first post-cast joint 8 to realize the support replacement.
[0023] After the second post-casting strip 9 of a basement structure 4 of a certain floor is poured, the steel truss interlayer 10 of the basement structure 4 of the next floor is removed, and then the temporary underground ground-connected wall 5 is removed; The temporary underground diaphragm wall 5 within 500mm of the subway protection zone and the cultural relics protection zone shall be demolished by a combination of static blasting and manual pneumatic picks to avoid the impact of the demolition of the temporary diaphragm wall on the safety of important surrounding buildings; the temporary underground diaphragm wall 5 in other areas shall be demolished by a combination of crushing guns and machinery. When demolishing, it is strictly forbidden to collide with the basement structure and the reserved beam and slab steel bars. When chiseling, pay attention to sprinkling water to reduce dust. When chiseling the bottom plate, the accumulated water in the pit shall be drained in time.
[0024] During construction: The first inner support 12 on the side where the construction layer is not demolished is retained, and the first inner support 12 on the side where the demolition is completed is temporarily removed and restored after the demolition is completed.
[0025] During the demolition of the temporary underground ground-connected wall 5, gas cutting is used to cut off the steel bars in the temporary underground ground-connected wall 5, and the mud mixed with slag is cleaned before cutting off the steel bars; The reserved steel bars on both sides of the temporary underground ground-connected wall 5 in the bottom plate area are covered with steel plates with a thickness of not less than 10 mm as horizontal hard protection to prevent garbage from entering and concrete fragments from damaging the reserved joints of the steel bars during demolition.
[0026] The I-beam brace 7 is removed, and the I-beam brace 7 is cut off by gas cutting and transported to the floor slab. The removed I-beam can be reused.
[0027] During the removal of rubble and debris, people are prohibited from standing in the support area when the temporary underground ground-connected wall 5 is demolished. After the demolition is completed, people who clean up the concrete debris are allowed to enter the demolition area for construction.
[0028] To meet environmental protection requirements, concrete blocks with a diameter greater than 300 mm need to be manually crushed for a second time. The debris on the structural beams and slabs on both sides of the temporary underground ground-connected wall 5 must be transported in a timely manner and must not be piled.
[0029] The post-cast joint is closed, and the floating rust on the surface of the steel bars thrown out of the post-cast joint can be removed by a hand-held electric grinder. Before pouring concrete, the steel bars that protrude from the deformed slab surface will be manually adjusted so that the deformation direction of the steel bars is parallel to the slab surface direction.
[0030] The post-casting belt concrete adopts shrinkage compensation concrete, and its concrete strength is increased by one level. Before pouring, the gradation of concrete is determined according to the wetness of the post-casting belt on site, and the gradation and slump of concrete are reasonably adjusted. The concrete is vibrated and compacted during pouring to ensure the casting quality of the post-casting belt, and maintenance is carried out as required after pouring.
[0031] The above embodiments are only some illustrations of the concept and implementation of the present invention, and are not intended to limit the same. Under the concept of the present invention, technical solutions that have not been substantially changed are still within the scope of protection.
Claims
1. A basement structure construction method combining compartment building and skip compartment demolition, comprising a subway protection area (1) and a cultural relic protection area (2), characterized in that: A foundation pit (3) is excavated and a basement structure (4) is constructed on a side that is in close contact with the subway protection zone (1) and a side that is adjacent to the cultural relics protection zone (2), wherein the foundation pit (3) is in a quadrilateral shape and avoids the subway protection zone (1) and the cultural relics protection zone (2), and the steps include: Step 1: According to the protection range of the subway protection area (1) and the cultural relics protection area (2), a temporary underground ground-connected wall (5) is set up to divide the interior of the foundation pit (3) into compartments; Step 2: supporting a permanent underground diaphragm wall (6) outside the foundation pit (3), constructing a temporary underground diaphragm wall (5) inside the foundation pit (3) to divide the foundation pit (3), and providing multiple groups of I-beam braces (7) on both sides of the temporary underground diaphragm wall (5), wherein the multiple I-beam braces (7) are distributed in a matrix shape; Step 3: excavate each compartment foundation pit (3) simultaneously to the bottom elevation of the first inner support (12), and then complete the construction of the crown beam (11) and the first inner support (12) of each compartment foundation pit (3); Step 4: construct the basement structure (4) of each sub-compartment foundation pit (3) in the order of distance from the subway protection area (1) and the cultural relics protection area (2) from far to near; Step 5: After the construction of the basement structure (4) of the compartment foundation pit (3) is completed, the formwork is removed after the basement structure (4) meets the structural strength and formwork removal conditions. After the formwork is removed, a steel truss interlayer (10) is set in each compartment foundation pit (3); Step 6: Divide the temporary underground ground-connected wall (5) into compartments, and remove the temporary underground ground-connected wall (5) by compartments. When the temporary underground diaphragm wall (5) is dismantled layer by layer in a descending order, when a temporary underground diaphragm wall (5) of a certain layer is dismantled, the multiple sets of I-beam supports (7) on both sides of the temporary underground diaphragm wall (5) of a certain layer are first replaced, and after the replacement is completed, the remaining wall of the temporary underground diaphragm wall (5) of the layer is dismantled. After the remaining wall is dismantled, the second post-casting strip (9) of the remaining area between the corresponding floor slabs of the basement structure (4) of the adjacent sub-layer foundation pit (3) is poured, and then the temporary underground diaphragm wall (5) of the next layer is dismantled after the next layer is dismantled. Until the temporary underground diaphragm wall (5) of the layer is completely dismantled, the temporary underground diaphragm wall (5) of the next layer is dismantled.
2. The basement structure construction method combining compartment building and skip compartment demolition according to claim 1 is characterized by: In the step 1, the layout position and design parameters of the temporary underground ground-connected wall (5) are determined based on the relative positional relationship between the foundation pit (3) and the subway protection area (1) and between the foundation pit (3) and the cultural relics protection area (2).
3. The basement structure construction method combining compartment building and skip compartment demolition according to claim 2 is characterized by: The arrangement principle of the temporary underground ground connection wall (5) is to form a regular polygon with the permanent underground ground connection wall (6), and the area of the regular polygon is larger the farther away from the subway protection area (1) and the cultural relics protection area (2).
4. The basement structure construction method combining compartment building and skip compartment demolition according to claim 1 is characterized by: In the second step, during the reinforcement binding process of the temporary underground ground-connected wall (5), multiple groups of I-beam braces (7) are placed and fixed at corresponding positions and cast in one step.
5. The basement structure construction method combining compartment building and skip compartment demolition according to claim 4 is characterized by: The I-beam brace (7) comprises two I-beams, which are supported on both sides of the temporary underground ground connection wall (5) respectively, one end of which is pre-buried in the floor slab side of the basement structure (4) of the compartment foundation pit (3) and the other end of which is supported on the side of the temporary underground ground connection wall (5).
6. The basement structure construction method combining compartment building and compartment demolition according to claim 1 is characterized by: In step 4, each compartment foundation pit (3) is first constructed in the order of earth excavation, internal support construction and foundation slab, and then each internal support is removed and the corresponding floor basement structure (4) is constructed in a bottom-up order.
7. The basement structure construction method combining compartment building and skip compartment demolition according to claim 1 is characterized by: In step six, the specific operation of replacing the support is to first remove a small area of the floor slab of the basement structure (4) at the position corresponding to the I-beam support (7), and then cast the first post-cast strip (8) to achieve the replacement of the support.
8. The basement structure construction method combining compartment building and skip compartment demolition according to claim 1 or 7 is characterized in that: In step six, after the second post-casting strip (9) is cast in a basement structure (4) of a certain floor, the steel truss interlayer (10) of the basement structure (4) of the next floor is removed, and then the temporary underground ground-connected wall (5) is removed.
9. The basement structure construction method combining compartment building and skip compartment demolition according to claim 1 is characterized by: Temporary underground diaphragm walls (5) within 500mm of the subway protection zone and the cultural relics protection zone are demolished by a combination of static blasting and manual pneumatic picks; temporary underground diaphragm walls (5) in other areas are demolished by a combination of crushing blasting and mechanical demolition.