A construction method for eccentric H-shaped steel connection nodes of underground continuous wall

Abstract

The present invention discloses an eccentric H-shaped steel connection node of an underground continuous wall and a construction method thereof, comprising the following steps: step one: measuring, laying out and determining pile positions, and driving H-shaped steel piles; step two: excavating earthwork, and cleaning the H-shaped steel pile connection holes of the pile body; step three: hoisting the H-shaped steel beam; step four: hoisting the prefabricated underground continuous wall in sections, and fixing and connecting the wall and the beam; step five: inserting the anchor sleeve into the reserved hole of the wall body; step six: high-pressure grouting in the cavity between the pile, the beam and the wall; step seven: driving the anchor rod; step eight: hoisting the prefabricated lower section of the underground continuous wall, and connecting the upper and lower adjacent prefabricated ground-connecting wall nodes; step nine: high-pressure spraying the surface layer in sections and layers; step ten: repeating steps two to nine until the construction of the entire ground-connecting wall enclosure structure is completed; the present invention adopts the scheme of "hoisting the prefabricated ground-connecting wall in sections and modules, designing the eccentric special-shaped H-shaped steel beam butt-jointed connection node, combining high-pressure grouting with anchor rod reinforcement", so as to realize the combination of structural force and water stopping.

Description

Technical Field

[0001] The invention belongs to the technical field of underground construction, and in particular relates to a construction method for an eccentric H-shaped steel connection node of an underground continuous wall. Background Art

[0002] As the main technical means of foundation pit retaining structure in construction projects, subway construction, etc., underground continuous wall can provide a safer and more reliable construction environment for underground structure construction. In view of the geological conditions of water-rich sand layers, the use of underground continuous wall retaining structure is more significant. The current traditional wet operation underwater pouring of concrete has certain adverse effects on construction quality, construction cost, construction progress and environmental protection.

[0003] At present, the safety of underground structure construction has become an important issue in the development of the industry. The underground continuous wall of the traditional cast-in-place structure construction has many construction processes, poor quality of finished products, a large gap between the actual load-bearing and the designed load-bearing, and the underground structure occupies a long construction period, which is not conducive to the green construction development requirements of the industry. Therefore, the present application provides an underground continuous wall eccentric H-shaped steel connection node and its construction method. Summary of the invention

[0004] The object of the present invention is to provide a construction method for an eccentric H-shaped steel connection node of an underground continuous wall to solve the problems raised in the above-mentioned background technology.

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

[0006] An eccentric H-shaped steel connection node of an underground continuous wall, comprising an H-shaped steel pile, a prefabricated underground continuous wall, an H-shaped steel beam, a high-strength bolt, an anchor rod and an anchor rod sleeve;

[0007] The H-shaped steel beam includes an upper edge-wrapped H-shaped steel beam and a lower edge-wrapped H-shaped steel beam;

[0008] The prefabricated underground continuous wall includes a prefabricated upper underground continuous wall and a prefabricated lower underground continuous wall;

[0009] The H-shaped steel piles and the upper and lower H-shaped steel beams form the main structural frame. The prefabricated upper underground continuous wall and the prefabricated lower underground continuous wall are connected by the upper and lower H-shaped steel beams. The upper and lower H-shaped steel beams are fixed by high-strength bolts. Anchor holes are opened on the webs of the upper and lower H-shaped steel beams. The upper and lower H-shaped steel beams are fixed by high-strength bolts. During the on-site lifting of the overall structure, the overall structure is paved in place through high-pressure grouting and preset anchor sleeves. The structural force is designed in combination with water stopping.

[0010] The prefabricated upper underground continuous wall and lower edge-wrapped H-shaped steel beam are designed and formed in an integrated manner in the PC factory, and the prefabricated lower underground continuous wall and upper edge-wrapped H-shaped steel beam are also designed and formed in an integrated manner in the PC factory.

[0011] A construction method for an eccentric H-shaped steel connection node of an underground continuous wall comprises the following steps:

[0012] Step 1: Measure and lay out the lines, determine the pile positions, and drive H-shaped steel piles;

[0013] Step 2: Excavate and clean the H-shaped steel pile connection holes;

[0014] Step 3: H-beam hoisting;

[0015] Step 4: Prefabricated underground continuous wall is hoisted in sections, and the wall and beam are fixedly connected;

[0016] Step 5: Insert the anchor sleeve into the reserved hole in the wall;

[0017] Step 6: High-pressure grouting in the cavities between piles, beams and walls;

[0018] Step 7: Install anchor rods;

[0019] Step 8: hoist the lower prefabricated underground continuous wall and connect the upper and lower adjacent prefabricated underground continuous wall nodes;

[0020] Step nine: segmented and layered high pressure spraying of the surface layer;

[0021] Step 10: Repeat steps 2 to 9 until the construction of all ground-connected wall enclosure structures is completed;

[0022] The specific steps are as follows:

[0023] Step 1: Measure and lay out the lines, determine the pile positions, and drive H-shaped steel piles:

[0024] In order to better realize the segmented and modular hoisting construction of underground continuous walls, H-shaped steel piles and H-shaped steel beams are used as the framework structure for connecting the sections of prefabricated underground continuous walls. First, on the basis of leveling the site, the positions of each H-shaped steel pile are measured and set on site according to the construction drawings, and the error is controlled within 10mm. The depth of the H-shaped steel pile is the excavation depth of the foundation pit + 1500mm; the pile body of the H-shaped steel pile is provided with an H-shaped steel beam connection hole in the subsequent process. In order to better resist the lateral pressure of the soil, the H-shaped steel beam connection hole at the connection node of the H-shaped steel pile and the H-shaped steel beam is arranged in an "inverted triangle" from the inside of the foundation pit to the outside of the foundation pit in the direction perpendicular to the foundation pit surface; after measuring and laying out the pile position, the H-shaped steel piles are driven one by one from the midpoint of the long side of the foundation pit to both sides, and the verticality of the H-shaped steel piles is controlled at 0.6%;

[0025] Step 2: Excavation and cleaning of the H-shaped steel pile connection holes:

[0026] After the H-shaped steel piles are driven, the excavation of the foundation pit soil is carried out in sections and layers combined with the center island method. First, the earthwork of the first layer is excavated. In order to stabilize the earthwork on the top of the foundation pit, an H-shaped steel slope protection beam is set on the top of the first layer of the foundation pit, and an H-shaped steel beam connection hole is set on the top of each H-shaped steel pile. After the excavation of the first layer of earthwork is completed, the stones and miscellaneous soil in the pile body connection hole are cleaned, and the distance between two adjacent H-shaped steel piles is accurately measured to adjust the error in time. After the first layer of earthwork is excavated 600mm, the H-shaped steel beam on the top of the foundation pit is hoisted and fixed. Anchor holes are set on the web of the H-shaped steel beam. After all the H-shaped steel beams on the first layer are hoisted and fixed and the holes are cleaned, anchor rods are driven one by one "from top to bottom, from inside to outside" to achieve the effect of stabilizing the first layer. On the other hand, earthwork excavation should be implemented simultaneously with precipitation engineering.

[0027] Step 3: H-beam hoisting:

[0028] After the connection holes of the H-shaped steel piles are cleaned, the H-shaped steel beams are hoisted and fixed on site with high-strength bolts. First, the H-shaped steel beams on the top of the H-shaped steel piles on the first floor are hoisted, and then the H-shaped steel beams between the lower pile bodies are hoisted. Each H-shaped steel beam is reinforced by driving anchor rods. Each H-shaped steel beam is no longer than 6m, and each H-shaped steel beam is equipped with 3 to 6 anchor rods. When a complex geological environment occurs, resulting in the design H-shaped steel beam being unable to meet the installation length during on-site hoisting, a welded triangular steel frame is used to assist the pile-beam connection work;

[0029] Step 4: Prefabricated underground continuous wall is hoisted in sections, and the wall and beam are fixedly connected:

[0030] The underground continuous wall is hoisted in sections and modules and combined with high-pressure grouting and anchor reinforcement. The prefabricated underground continuous wall and H-shaped steel beam in each module are designed to be integrated, that is, at the connection nodes of the adjacent prefabricated underground continuous walls at the upper and lower ends, each prefabricated underground continuous wall and the H-shaped steel beam are prefabricated and formed in an integrated manner in the PC factory in the early stage, forming a "two H-shaped steel beam butt connection node" between the upper and lower prefabricated underground continuous walls, forming a butt connection state of the upper edge-wrapped H-shaped steel beam and the lower edge-wrapped H-shaped steel beam; in order to better realize the on-site hoisting and fixation of the prefabricated underground continuous wall, anchor holes are also provided on the webs of the upper edge-wrapped H-shaped steel beam and the lower edge-wrapped H-shaped steel beam at the connection node, so as to facilitate the subsequent installation of anchors to achieve a reliable connection between the prefabricated underground continuous wall and the H-shaped steel beam; it should be noted here that the on-site hoisting construction is done in sections from top to bottom, that is, the prefabricated upper section of the underground continuous wall is hoisted first, and then the prefabricated lower section of the underground continuous wall is hoisted until all hoisting is completed.

[0031] Step 5: Insert the anchor sleeve into the reserved hole in the wall:

[0032] After the prefabricated underground continuous wall is hoisted in place, anchor sleeves are provided at the reserved holes on the webs of the upper H-shaped steel beam and the webs of the lower H-shaped steel beam at the connection nodes of the upper and lower adjacent prefabricated underground continuous walls, because high-pressure grouting should be carried out on the cavities and gaps between the hoisted components before the installation of each anchor. In addition, anchor holes are also provided on the prefabricated underground continuous wall that has been hoisted. In order to meet the requirements of anchor construction in subsequent processes, the design adopts a special anchor sleeve pre-installation scheme for on-site construction. The length of each anchor sleeve is not less than 450mm, and the outer wall of the anchor sleeve is provided with a crescent-shaped connecting rib, which is used to improve the connection strength between the high-pressure grouting in the cavity and the anchor.

[0033] Step 6: High-pressure grouting in the cavities between piles, beams and walls:

[0034] After the H-shaped steel piles, H-shaped steel beams and prefabricated underground continuous walls in each construction section are hoisted and fixed, anchor sleeves are installed in the anchor holes at each designed anchor position. The installation angle and position relationship of the anchor sleeves are consistent with the corresponding anchor position. After all anchor sleeves are installed, high-pressure grouting is used in the cavities between piles, beams and walls to provide a favorable technical environment for the subsequent anchor installation process. High-pressure grouting is used to fill the cavities between piles, beams and walls on site. The positions of the grouting holes are pre-designed on the webs of the H-shaped steel beams and the walls of the prefabricated underground continuous walls. High-pressure grouting can also be performed through anchor sleeves. The high-pressure grouting in the cavities between piles, beams and walls adopts the technical solution of "grouting at the connection nodes of the upper and lower adjacent prefabricated underground continuous walls in each section, and the grouting material is forced to squeeze from the bottom and fill the gap between the prefabricated underground continuous wall and the soil by high pressure";

[0035] Step 7: Anchor bolt installation:

[0036] After the prefabricated upper underground continuous wall is hoisted and fixed, anchors are installed one by one at the designed anchor positions in the construction section. The length of the anchors is not less than 1500mm. The anchors are installed through the fixed anchor sleeve positions. The anchor sleeve provides a drilling guide for the anchors. The anchor sleeve must not be forcibly interfered with during the anchor installation process. The inner diameter of the anchor sleeve is 3mm larger than the designed anchor hole diameter. The anchor installation in each section adopts the technical solution of "first installing the H-shaped steel beam at the node of the two adjacent prefabricated underground continuous walls, and then installing the prefabricated underground continuous wall";

[0037] Step 8: Prefabricated lower underground continuous wall hoisting, upper and lower adjacent prefabricated ground wall nodes connection:

[0038] After the prefabricated upper underground continuous wall is hoisted and fixed and the anchor rods are driven, the hoisting work of the prefabricated lower underground continuous wall is carried out; the lower part of the prefabricated upper underground continuous wall is provided with a lower edge-wrapped H-shaped steel beam after it is in place, and the upper end of the prefabricated lower underground continuous wall is provided with an upper edge-wrapped H-shaped steel beam. The upper edge-wrapped H-shaped steel beam and the lower edge-wrapped H-shaped steel beam are the connection nodes of the upper and lower adjacent prefabricated upper underground continuous wall and the prefabricated lower underground continuous wall. The upper edge-wrapped H-shaped steel beam and the lower edge-wrapped H-shaped steel beam are fixed at the connection nodes with high-strength bolts, and the two ends of the upper edge-wrapped H-shaped steel beam and the lower edge-wrapped H-shaped steel beam are respectively fixed with the H-shaped The steel piles are connected and fixed, and the flange plates where the upper H-beam and the lower H-beam are connected form a "symmetrical Z-shaped reverse multi-path water stop" state in the direction of groundwater flow; from the perspective of force design, the upper H-beam and the lower H-beam form an "external eccentric state" for the entire underground continuous wall section after being connected, so as to better resist the horizontal side pressure of the soil and the groundwater pressure. Combined with the overall technical solution, a new technical system is formed, including H-beam piles, integrated H-beam prefabricated underground continuous walls, anchor rod driving under the guidance of special sleeves, and high-pressure grouting technology;

[0039] Step 9: Segmented and layered high-pressure spraying of the surface layer:

[0040] After all the above processes are completed, the cavity near the foundation pit at the upper and lower adjacent prefabricated diaphragm wall nodes is filled with micro-expansion, low-shrinkage, high-strength fine stone concrete, and then the surface layer is sprayed in sections and layers with high pressure together with the outer surface of the prefabricated underground continuous wall and the connection node in this construction section. The thickness of the surface layer spraying is not less than 16mm, and the spraying is carried out three times;

[0041] Step 10: Repeat steps 2 to 9 until the construction of all ground-connected wall enclosure structures is completed:

[0042] The construction of underground continuous walls is carried out in layers, sections and modules from top to bottom. After all the structures in the previous construction section are completed, repeat steps 2 to 9 until the construction of all underground continuous wall enclosure structures is completed.

[0043] Technical effects and advantages of the present invention:

[0044] The present invention adopts the technical scheme of "prefabricated ground-anchored wall segmented and module-based hoisting, eccentric special-shaped H-shaped steel beam butt connection node design, combined with high-pressure grouting and anchor reinforcement", adopts prefabricated hoisting combined with steel structure connection design, layered hoisting, segmented splicing and fixing, module anchor rods and grouting reinforcement, to achieve the combination of structural force and water stopping, safe and reliable, fast construction speed, in line with the requirements of green construction of assembly construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a schematic diagram of an eccentric H-shaped steel connection node structure of an underground continuous wall;

[0046] Figure 2 A schematic diagram of an anchor sleeve in an eccentric H-shaped steel connection node structure of an underground continuous wall;

[0047] Figure 3 This is a construction process flow chart for an eccentric H-steel connection node of an underground continuous wall.

[0048] In the figure: 11. Prefabricated upper underground continuous wall; 12. Prefabricated lower underground continuous wall; 21. Upper edge-wrapped H-shaped steel beam; 22. Lower edge-wrapped H-shaped steel beam roadbed beam; 3. High-strength bolts; 41. Anchor rods; 42. Anchor rod sleeves. DETAILED DESCRIPTION

[0049] The following will be combined with the attached embodiment of the present invention Figure 1-Figure 2 , the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Example

[0050] An eccentric H-shaped steel connection node of an underground continuous wall, comprising an H-shaped steel pile, a prefabricated underground continuous wall, an H-shaped steel beam, a high-strength bolt, an anchor rod and an anchor rod sleeve;

[0051] The H-shaped steel beam includes an upper edge-wrapped H-shaped steel beam and a lower edge-wrapped H-shaped steel beam;

[0052] The prefabricated underground continuous wall includes a prefabricated upper underground continuous wall and a prefabricated lower underground continuous wall;

[0053] The H-shaped steel piles and the upper and lower H-shaped steel beams form the main structural frame. The prefabricated upper underground continuous wall and the prefabricated lower underground continuous wall are connected by the upper and lower H-shaped steel beams. The upper and lower H-shaped steel beams are fixed by high-strength bolts. Anchor holes are opened on the webs of the upper and lower H-shaped steel beams. The upper and lower H-shaped steel beams are fixed by high-strength bolts. During the on-site lifting of the overall structure, the overall structure is paved in place through high-pressure grouting and preset anchor sleeves. The structural force is designed in combination with water stopping.

[0054] The prefabricated upper underground continuous wall and lower edge-wrapped H-shaped steel beam are designed and formed in an integrated manner in the PC factory, and the prefabricated lower underground continuous wall and upper edge-wrapped H-shaped steel beam are also designed and formed in an integrated manner in the PC factory.

[0055] A construction method for an eccentric H-shaped steel connection node of an underground continuous wall comprises the following steps:

[0056] Step 1: Measure and lay out the lines, determine the pile positions, and drive H-shaped steel piles;

[0057] Step 2: Excavate and clean the H-shaped steel pile connection holes;

[0058] Step 3: H-beam hoisting;

[0059] Step 4: Prefabricated underground continuous wall is hoisted in sections, and the wall and beam are fixedly connected;

[0060] Step 5: Insert the anchor sleeve into the reserved hole in the wall;

[0061] Step 6: High-pressure grouting in the cavities between piles, beams and walls;

[0062] Step 7: Install anchor rods;

[0063] Step 8: hoist the lower prefabricated underground continuous wall and connect the upper and lower adjacent prefabricated underground continuous wall nodes;

[0064] Step nine: segmented and layered high pressure spraying of the surface layer;

[0065] Step 10: Repeat steps 2 to 9 until the construction of all ground-connected wall enclosure structures is completed;

[0066] The specific steps are as follows:

[0067] Step 1: Measure and lay out the lines, determine the pile positions, and drive H-shaped steel piles:

[0068] In order to better realize the segmented and modular hoisting construction of underground continuous walls, H-shaped steel piles and H-shaped steel beams are used as the framework structure for connecting the sections of prefabricated underground continuous walls. First, on the basis of leveling the site, the positions of each H-shaped steel pile are measured and set on site according to the construction drawings, and the error is controlled within 10mm. The depth of the H-shaped steel pile is the excavation depth of the foundation pit + 1500mm; the pile body of the H-shaped steel pile is provided with an H-shaped steel beam connection hole in the subsequent process. In order to better resist the lateral pressure of the soil, the H-shaped steel beam connection hole at the connection node of the H-shaped steel pile and the H-shaped steel beam is arranged in an "inverted triangle" from the inside of the foundation pit to the outside of the foundation pit in the direction perpendicular to the foundation pit surface; after measuring and laying out the pile position, the H-shaped steel piles are driven one by one from the midpoint of the long side of the foundation pit to both sides, and the verticality of the H-shaped steel piles is controlled at 0.6%;

[0069] Step 2: Excavation and cleaning of the H-shaped steel pile connection holes:

[0070] After the H-shaped steel piles are driven, the excavation of the foundation pit soil is carried out in sections and layers combined with the center island method. First, the earthwork of the first layer is excavated. In order to stabilize the earthwork on the top of the foundation pit, an H-shaped steel slope protection beam is set on the top of the first layer of the foundation pit, and an H-shaped steel beam connection hole is set on the top of each H-shaped steel pile. After the excavation of the first layer of earthwork is completed, the stones and miscellaneous soil in the pile body connection hole are cleaned, and the distance between two adjacent H-shaped steel piles is accurately measured to adjust the error in time. After the first layer of earthwork is excavated 600mm, the H-shaped steel beam on the top of the foundation pit is hoisted and fixed. Anchor holes are set on the web of the H-shaped steel beam. After all the H-shaped steel beams on the first layer are hoisted and fixed and the holes are cleaned, anchor rods are driven one by one "from top to bottom, from inside to outside" to achieve the effect of stabilizing the first layer. On the other hand, earthwork excavation should be implemented simultaneously with precipitation engineering.

[0071] Step 3: H-beam hoisting:

[0072] After the connection holes of the H-shaped steel piles are cleaned, the H-shaped steel beams are hoisted and fixed on site with high-strength bolts. First, the H-shaped steel beams on the top of the H-shaped steel piles on the first floor are hoisted, and then the H-shaped steel beams between the lower pile bodies are hoisted. Each H-shaped steel beam is reinforced by driving anchor rods. Each H-shaped steel beam is no longer than 6m, and each H-shaped steel beam is equipped with 3 to 6 anchor rods. When a complex geological environment occurs, resulting in the design H-shaped steel beam being unable to meet the installation length during on-site hoisting, a welded triangular steel frame is used to assist the pile-beam connection work;

[0073] Step 4: Prefabricated underground continuous wall is hoisted in sections, and the wall and beam are fixedly connected:

[0074] The underground continuous wall is hoisted in sections and modules and combined with high-pressure grouting and anchor reinforcement. The prefabricated underground continuous wall and H-shaped steel beam in each module are designed to be integrated, that is, at the connection nodes of the adjacent prefabricated underground continuous walls at the upper and lower ends, each prefabricated underground continuous wall and the H-shaped steel beam are prefabricated and formed in an integrated manner in the PC factory in the early stage, forming a "two H-shaped steel beam butt connection node" between the upper and lower prefabricated underground continuous walls, forming a butt connection state of the upper edge-wrapped H-shaped steel beam and the lower edge-wrapped H-shaped steel beam; in order to better realize the on-site hoisting and fixation of the prefabricated underground continuous wall, anchor holes are also provided on the webs of the upper edge-wrapped H-shaped steel beam and the lower edge-wrapped H-shaped steel beam at the connection node, so as to facilitate the subsequent installation of anchors to achieve a reliable connection between the prefabricated underground continuous wall and the H-shaped steel beam; it should be noted here that the on-site hoisting construction is done in sections from top to bottom, that is, the prefabricated upper section of the underground continuous wall is hoisted first, and then the prefabricated lower section of the underground continuous wall is hoisted until all hoisting is completed.

[0075] Step 5: Insert the anchor sleeve into the reserved hole in the wall:

[0076] After the prefabricated underground continuous wall is hoisted in place, anchor sleeves are provided at the reserved holes on the webs of the upper H-shaped steel beam and the webs of the lower H-shaped steel beam at the connection nodes of the upper and lower adjacent prefabricated underground continuous walls, because high-pressure grouting should be carried out on the cavities and gaps between the hoisted components before the installation of each anchor. In addition, anchor holes are also provided on the prefabricated underground continuous wall that has been hoisted. In order to meet the requirements of anchor construction in subsequent processes, the design adopts a special anchor sleeve pre-installation scheme for on-site construction. The length of each anchor sleeve is not less than 450mm, and the outer wall of the anchor sleeve is provided with a crescent-shaped connecting rib, which is used to improve the connection strength between the high-pressure grouting in the cavity and the anchor.

[0077] Step 6: High-pressure grouting in the cavities between piles, beams and walls:

[0078] After the H-shaped steel piles, H-shaped steel beams and prefabricated underground continuous walls in each construction section are hoisted and fixed, anchor sleeves are installed in the anchor holes at each designed anchor position. The installation angle and position relationship of the anchor sleeves are consistent with the corresponding anchor position. After all anchor sleeves are installed, high-pressure grouting is used in the cavities between piles, beams and walls to provide a favorable technical environment for the subsequent anchor installation process. High-pressure grouting is used to fill the cavities between piles, beams and walls on site. The positions of the grouting holes are pre-designed on the webs of the H-shaped steel beams and the walls of the prefabricated underground continuous walls. High-pressure grouting can also be performed through anchor sleeves. The high-pressure grouting in the cavities between piles, beams and walls adopts the technical solution of "grouting at the connection nodes of the upper and lower adjacent prefabricated underground continuous walls in each section, and the grouting material is forced to squeeze from the bottom and fill the gap between the prefabricated underground continuous wall and the soil by high pressure";

[0079] Step 7: Anchor bolt installation:

[0080] After the prefabricated upper underground continuous wall is hoisted and fixed, anchors are installed one by one at the designed anchor positions in the construction section. The length of the anchors is not less than 1500mm. The anchors are installed through the fixed anchor sleeve positions. The anchor sleeve provides a drilling guide for the anchors. The anchor sleeve must not be forcibly interfered with during the anchor installation process. The inner diameter of the anchor sleeve is 3mm larger than the designed anchor hole diameter. The anchor installation in each section adopts the technical solution of "first installing the H-shaped steel beam at the node of the two adjacent prefabricated underground continuous walls, and then installing the prefabricated underground continuous wall";

[0081] Step 8: Prefabricated lower underground continuous wall hoisting, upper and lower adjacent prefabricated ground wall nodes connection:

[0082] After the prefabricated upper underground continuous wall is hoisted and fixed and the anchor rods are driven, the hoisting work of the prefabricated lower underground continuous wall is carried out; the lower part of the prefabricated upper underground continuous wall is provided with a lower edge-wrapped H-shaped steel beam after it is in place, and the upper end of the prefabricated lower underground continuous wall is provided with an upper edge-wrapped H-shaped steel beam. The upper edge-wrapped H-shaped steel beam and the lower edge-wrapped H-shaped steel beam are the connection nodes of the upper and lower adjacent prefabricated upper underground continuous wall and the prefabricated lower underground continuous wall. The upper edge-wrapped H-shaped steel beam and the lower edge-wrapped H-shaped steel beam are fixed at the connection nodes with high-strength bolts, and the two ends of the upper edge-wrapped H-shaped steel beam and the lower edge-wrapped H-shaped steel beam are respectively fixed with the H-shaped The steel piles are connected and fixed, and the flange plates where the upper H-beam and the lower H-beam are connected form a "symmetrical Z-shaped reverse multi-path water stop" state in the direction of groundwater flow; from the perspective of force design, the upper H-beam and the lower H-beam form an "external eccentric state" for the entire underground continuous wall section after being connected, so as to better resist the horizontal side pressure of the soil and the groundwater pressure. Combined with the overall technical solution, a new technical system is formed, including H-beam piles, integrated H-beam prefabricated underground continuous walls, anchor rod driving under the guidance of special sleeves, and high-pressure grouting technology;

[0083] Step 9: Segmented and layered high-pressure spraying of the surface layer:

[0084] After all the above processes are completed, the cavity near the foundation pit at the upper and lower adjacent prefabricated diaphragm wall nodes is filled with micro-expansion, low-shrinkage, high-strength fine stone concrete, and then the surface layer is sprayed in sections and layers with high pressure together with the outer surface of the prefabricated underground continuous wall and the connection node in this construction section. The thickness of the surface layer spraying is not less than 16mm, and the spraying is carried out three times;

[0085] Step 10: Repeat steps 2 to 9 until the construction of all ground-connected wall enclosure structures is completed:

[0086] The construction of underground continuous walls is carried out in layers, sections and modules from top to bottom. After all the structures in the previous construction section are completed, repeat steps 2 to 9 until the construction of all underground continuous wall enclosure structures is completed.

[0087] The present invention adopts the technical scheme of "prefabricated ground-connected walls are hoisted in sections and modules, eccentric special-shaped H-shaped steel beams are butt-jointed and connected at the nodes, and high-pressure grouting is combined with anchor reinforcement" to achieve the combination of structural force and water stopping.

[0088] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A construction method for an eccentric H-shaped steel connection node of an underground continuous wall, characterized in that: Including H-shaped steel piles, prefabricated underground continuous walls, H-shaped steel beams, high-strength bolts and anchor rods; The H-shaped steel beam includes an upper edge-wrapped H-shaped steel beam and a lower edge-wrapped H-shaped steel beam; The prefabricated underground continuous wall includes a prefabricated upper underground continuous wall and a prefabricated lower underground continuous wall; The H-shaped steel piles and the upper and lower H-shaped steel beams form the main structural frame. The prefabricated upper underground continuous wall and the prefabricated lower underground continuous wall are connected by the upper and lower H-shaped steel beams. The upper and lower H-shaped steel beams are connected and fixed by high-strength bolts. Anchor holes are opened on the webs of the upper and lower H-shaped steel beams. The upper and lower H-shaped steel beams are fixed by high-strength bolts. During the on-site hoisting of the overall structure, the overall paving is carried out in place by high-pressure grouting and preset anchor sleeves. The prefabricated upper underground continuous wall and the lower edge-wrapped H-shaped steel beam are integrally designed and formed in the PC factory, and the prefabricated lower underground continuous wall and the upper edge-wrapped H-shaped steel beam are also integrally designed and formed in the PC factory; The following steps are also included: Step 1: Measure and lay out the lines, determine the pile positions, and drive H-shaped steel piles; Step 2: Excavate and clean the H-shaped steel pile connection holes; Step 3: H-beam hoisting; Step 4: Prefabricated underground continuous wall is hoisted in sections, and the wall and beam are fixedly connected; Step 5: Insert the anchor sleeve into the reserved hole in the wall; Step 6: High-pressure grouting in the cavities between piles, beams and walls; Step 7: Install anchor rods; Step 8: hoist the lower prefabricated underground continuous wall and connect the upper and lower adjacent prefabricated underground continuous wall nodes; Step nine: segmented and layered high pressure spraying of the surface layer; Step 10: Repeat steps 2 to 9 until the construction of all ground-connected wall enclosure structures is completed; The specific steps are as follows: Step 1: Measure and lay out the lines, determine the pile positions, and drive H-shaped steel piles: First, on the basis of leveling the site, the location of each H-shaped steel pile was measured and set on site according to the construction drawings, with the error controlled within 10mm. The depth of the H-shaped steel pile was the excavation depth of the foundation pit + 1500mm. The pile body of the H-shaped steel pile was provided with an H-shaped steel beam connection hole in the subsequent process. In order to better resist the lateral pressure of the soil, the H-shaped steel beam connection hole at the connection node of the H-shaped steel pile and the H-shaped steel beam was arranged in an "inverted triangle" from the inside of the foundation pit to the outside of the foundation pit in the vertical direction of the foundation pit surface. After measuring and setting out the pile position, the H-shaped steel piles were driven one by one from the midpoint of the long side of the foundation pit to both sides, and the verticality of the H-shaped steel piles was controlled at 0.6%. Step 2: Excavation and cleaning of the H-shaped steel pile connection holes: After the H-shaped steel piles are driven, the excavation of the foundation pit soil is carried out in sections and layers combined with the center island method. First, the earthwork of the first layer is excavated. In order to stabilize the earthwork on the top of the foundation pit, an H-shaped steel slope protection beam is set on the top of the first layer of the foundation pit, and an H-shaped steel beam connection hole is set on the top of each H-shaped steel pile. After the excavation of the first layer of earthwork is completed, the stones and miscellaneous soil in the pile body connection hole are cleaned, and the distance between two adjacent H-shaped steel piles is accurately measured to adjust the error in time. After the first layer of earthwork is excavated 600mm, the H-shaped steel beam on the top of the foundation pit is hoisted and fixed. Anchor holes are set on the web of the H-shaped steel beam. After all the H-shaped steel beams on the first layer are hoisted and fixed and the holes are cleaned, anchor rods are driven one by one from top to bottom and from inside to outside to stabilize the first layer. On the other hand, earthwork excavation should be implemented simultaneously with precipitation engineering. Step 3: H-beam hoisting: After the connection holes of the H-shaped steel piles are cleaned, the H-shaped steel beams are hoisted and fixed on site with high-strength bolts. First, the H-shaped steel beams on the top of the H-shaped steel piles on the first floor are hoisted, and then the H-shaped steel beams between the lower pile bodies are hoisted. Each H-shaped steel beam is reinforced by driving anchor rods. Each H-shaped steel beam is no longer than 6m, and each H-shaped steel beam is equipped with 3 to 6 anchor rods. When a complex geological environment occurs, resulting in the H-shaped steel beam being unable to meet the installation length during on-site hoisting, a welded triangular steel frame is used to assist the pile-beam connection work; Step 4: Prefabricated underground continuous wall is hoisted in sections, and the wall and beam are fixedly connected: The underground continuous wall is hoisted in sections and modules and combined with high-pressure grouting and anchor reinforcement. The prefabricated underground continuous wall and H-shaped steel beam in each module are designed to be integrated, that is, at the connection nodes of the adjacent prefabricated underground continuous walls at the upper and lower ends, each prefabricated underground continuous wall and the H-shaped steel beam are prefabricated and formed in an integrated manner in the PC factory in the early stage, forming a "two H-shaped steel beam butt connection node" between the upper and lower prefabricated underground continuous walls, forming a butt connection state between the upper edge-wrapped H-shaped steel beam and the lower edge-wrapped H-shaped steel beam; in order to better realize the on-site hoisting and fixation of the prefabricated underground continuous wall, anchor holes are also provided on the webs of the upper edge-wrapped H-shaped steel beam and the lower edge-wrapped H-shaped steel beam at the connection node, so that anchors can be driven later to achieve a reliable connection between the prefabricated underground continuous wall and the H-shaped steel beam; Step 5: Insert the anchor sleeve into the reserved hole in the wall: After the prefabricated underground continuous wall is hoisted in place, anchor sleeves are provided at the reserved holes on the webs of the upper H-shaped steel beam and the webs of the lower H-shaped steel beam at the connection nodes of the upper and lower adjacent prefabricated underground continuous walls, and anchor holes are also provided on the prefabricated underground continuous wall that has been hoisted; in order to meet the requirements of anchor construction in the subsequent process, the length of each anchor sleeve is not less than 450mm, and the outer wall of the anchor sleeve is provided with a crescent-shaped connecting rib, which is used to improve the connection strength between the high-pressure grouting in the cavity and the anchor; Step 6: High-pressure grouting in the cavities between piles, beams and walls: After the H-shaped steel piles, H-shaped steel beams and prefabricated underground continuous walls in each construction section are hoisted and fixed, anchor sleeves are installed in the anchor holes at each designed anchor position. The installation angle and position relationship of the anchor sleeves are consistent with the corresponding anchor position. After all anchor sleeves are installed, high-pressure grouting is used in the cavities between piles, beams and walls to provide a favorable technical environment for the subsequent anchor installation process. High-pressure grouting is used to fill the cavities between piles, beams and walls on site. The positions of the grouting holes are pre-designed on the webs of the H-shaped steel beams and the walls of the prefabricated underground continuous walls. High-pressure grouting can also be performed through anchor sleeves. The high-pressure grouting in the cavities between piles, beams and walls adopts the technical solution of "grouting at the connection nodes of the upper and lower adjacent prefabricated underground continuous walls in each section, and the grouting material is forced to squeeze from the bottom and fill the gap between the prefabricated underground continuous wall and the soil by high pressure". Step 7: Anchor bolt installation: After the prefabricated upper underground continuous wall is hoisted and fixed, anchors are installed one by one at the designed anchor positions in the construction section. The length of the anchors is not less than 1500mm. The anchors are installed through the fixed anchor sleeve positions. The anchor sleeve provides a drilling guide for the anchors. The inner diameter of the anchor sleeve is 3mm larger than the designed anchor hole diameter. The anchors in each section adopt the technical solution of "first installing the H-shaped steel beams at the nodes of the two adjacent prefabricated underground continuous walls, and then installing the prefabricated underground continuous wall"; Step 8: Prefabricated lower underground continuous wall hoisting, upper and lower adjacent prefabricated ground wall nodes connection: After the prefabricated upper underground continuous wall is hoisted and fixed and the anchor rods are driven, the hoisting work of the prefabricated lower underground continuous wall is carried out; the lower part of the prefabricated upper underground continuous wall is provided with a lower edge-wrapped H-shaped steel beam after it is in place, and the upper end of the prefabricated lower underground continuous wall is provided with an upper edge-wrapped H-shaped steel beam. The upper edge-wrapped H-shaped steel beam and the lower edge-wrapped H-shaped steel beam are the connection nodes of the upper and lower adjacent prefabricated upper underground continuous wall and the prefabricated lower underground continuous wall. The upper edge-wrapped H-shaped steel beam and the lower edge-wrapped H-shaped steel beam are fixed at the connection nodes with high-strength bolts, and the two ends of the upper edge-wrapped H-shaped steel beam and the lower edge-wrapped H-shaped steel beam are respectively fixed with the H-shaped The steel piles are connected and fixed, and the flange plates where the upper H-beam and the lower H-beam are connected form a "symmetrical Z-shaped reverse multi-path water stop" state in the direction of underground water flow; from the perspective of force design, the upper H-beam and the lower H-beam form an "external eccentric state" for the entire underground continuous wall section after being connected, so as to better resist the horizontal side pressure of the soil and the groundwater pressure. Combined with the overall technical solution, a new technical system is formed, including H-beam piles, integrated H-beam prefabricated underground continuous walls, anchor rod driving under the guidance of special sleeves, and high-pressure grouting technology; Step 9: Segmented and layered high-pressure spraying of the surface layer: After all the above processes are completed, the cavity near the foundation pit at the upper and lower adjacent prefabricated diaphragm wall nodes is filled with micro-expansion, low-shrinkage, high-strength fine stone concrete, and then the surface layer is sprayed in sections and layers with high pressure together with the outer surface of the prefabricated underground continuous wall and the connection node in this construction section. The thickness of the surface layer spraying is not less than 16mm, and the spraying is carried out three times; Step 10: Repeat steps 2 to 9 until the construction of all ground-connected wall enclosure structures is completed: The construction of underground continuous walls is carried out in layers, sections and modules from top to bottom. After all the structures in the previous construction section are completed, repeat steps 2 to 9 until the construction of all underground continuous wall enclosure structures is completed.

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