Method for constructing vertical shaft supporting segment structure through composite materials and muck

Abstract

The invention discloses a method for constructing a vertical shaft supporting segment structure through composite materials and muck. The method comprises the following steps that S1, an arc-shaped box body with an opening in the top and a cover plate used for sealing the top of the box body are manufactured; s2, muck slurry generated by vertical shaft tunneling is treated, coarse aggregate is separated out through a pre-screening device, sandy particles are separated out through a first-stage cyclone, and clay particles are separated out through a second-stage cyclone in sequence; wherein the coarse aggregate and the concrete are mixed to obtain bottom sealing concrete, the sandy particles and the muck modifier are mixed to obtain modified muck, the sandy particles and the cement mortar are mixed to obtain wall rear cement mortar, and the clay particles and the additive are mixed to obtain modified slurry; and S3, foundation pit excavation is conducted through the slurry balance vertical shaft heading machine, and a vertical shaft supporting segment structure is built. The method has the advantages that the vertical shaft tunneling muck slurry is recycled, and certain economic and environmental benefits are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of shaft construction, and in particular relates to a method for constructing a shaft support segment structure by utilizing composite materials and slag. Background Art

[0002] In the construction of the shaft, the support system after excavation is usually a prefabricated concrete support segment. The segment is made by the factory through processes such as tying steel bars, supporting formwork, pouring concrete, and then transported to the construction site. Due to the high density of reinforced concrete, the mass of the produced segment is very large, reaching several tons, and it cannot be transported and installed by manual or light machinery. Large lifting equipment and robotic arms are often used to cooperate with the construction. On the one hand, the use of large equipment will incur large equipment costs. On the other hand, alignment and splicing during the construction process need to be achieved by remote control, which will also take a lot of time. At the same time, the segments are usually connected by staggered bent bolts. As long as there is a slight deviation, it is difficult for the bolts to penetrate the two connected segments. However, there will be certain errors in the prefabricated segments, bolts, and installation process. These errors accumulate, and the bolts often cannot be installed. If brute force is used to penetrate the two connected segments, there is a greater risk of segment rupture.

[0003] In addition, during the excavation of the shaft foundation pit, especially vertical excavation using the slurry balance shaft excavation method, a large amount of waste mud will be generated. The mud needs to be pre-treated before it can be transported and dumped, otherwise it will pollute the environment.

[0004] Therefore, there is a need for a method for constructing a shaft support segment structure using composite materials and slag that can solve the above-mentioned problems. Summary of the invention

[0005] The object of the present invention is to provide a method for constructing a shaft support segment structure using composite materials and slag soil in accordance with the above-mentioned deficiencies in the prior art. The method forms coarse aggregate, sandy particles and clay particles through pre-screening and cyclone methods for the slag soil slurry generated during the shaft excavation process. The coarse aggregate can be used in the concrete of the shaft bottom sealing, the sandy particles can be used for mixing cement mortar for back-wall grouting, the modified sandy particles are used for filling the inside of the segment, and the modified clay particles can be used as drag-reducing slurry during the sinking process of the shaft, thereby realizing the reuse of the slag soil slurry generated during the shaft excavation process and having certain economic and environmental benefits.

[0006] The purpose of the present invention is achieved by the following technical solutions: A method for constructing a shaft support segment structure using composite materials and slag, the method comprising the following steps: S1: manufacturing an arc-shaped box body with an open top and a cover plate for closing the top of the box body; S2: Processing the slag mud generated during shaft excavation, separating the coarse aggregate through the pre-screener, separating the sand particles through the first-stage cyclone, and separating the clay particles through the second-stage cyclone; The coarse aggregate and concrete are mixed to obtain bottom concrete, the sand particles and slag modifier are mixed to obtain modified slag, the sand particles and cement mortar are mixed to obtain back-wall cement mortar, and the clay particles and admixture are mixed to obtain modified mud; S3: Excavate the foundation pit and construct the shaft support segment structure using a slurry balance shaft boring machine; S3.1: Construction blade foot ring; S3.2: Installing an initial ring of the shaft support segment structure; The modified slag is filled in the box and sealed by the cover plate to form segments, and the segments are assembled annularly to form a shaft segment ring; S3.3: Preparation before excavation of the slurry balance shaft boring machine; S3.4: Install the remaining rings of the shaft support segment structure; S3.5: filling the modified mud between the shaft support segment structure and the surrounding rock, and using the modified mud to assist the shaft support segment structure in sinking; S3.6: The bottom sealing concrete is poured at the bottom of the shaft support segment structure to seal the bottom, and the modified mud between the shaft support segment structure and the surrounding rock is replaced by the cement mortar behind the wall, so that the shaft support segment structure and the surrounding rock form an integral force-bearing structure.

[0007] The bottom of the box body and the cover plate are both provided with wedge holes for installing wedges, and the number and positions of the wedge holes on the bottom of the box body correspond to the number and positions of the wedge holes on the cover plate; tenon structures and mortise structures are respectively provided at both ends of the box body, and the circumferentially adjacent boxes are connected by the cooperation of the tenon structures and the mortise structures, and sealing strips are provided at the connections of the circumferentially adjacent boxes.

[0008] The sealing strip is provided on the raised part of the tenon structure and on both sides of the raised part, and the sealing strip is provided on the groove part of the mortise structure and on both sides of the groove part. The number and position of the sealing strips on the tenon structure correspond to the number and position of the sealing strips on the mortise structure.

[0009] The inner walls of the two circular arc vertical plates of the box body are both provided with stiffening ribs.

[0010] The specific steps of step S3.2 are as follows: S3.2.1: Apply epoxy glue to the tenon and mortise structures of the box; S3.2.2: The opening of the box is facing upwards and assembled in a circular manner, and the box is connected to the blade foot ring; S3.2.3: Fill the modified slag into the box in batches, and the filling thickness each time shall not exceed 20 cm; S3.2.4: using a vibrating compactor to compact the modified slag in the box to reduce the pores of the modified slag in the box so that the modified slag is evenly distributed; S3.2.5: Repeat steps S3.2.3 and S3.2.4 until the modified slag in the box body is filled to the upper surface of the box body; S3.2.6: Apply epoxy glue on the cover plate, cover it on the box body, and glue it; S3.2.7: Use an annular cutter to vertically dig out the modified slag from the wedge hole of the cover plate to form a hole.

[0011] The specific steps of step S3.4 are as follows: S3.4.1: Excavation of soil by slurry balance shaft boring machine; S3.4.2: Apply epoxy glue on the cover plate of the shaft segment ring; S3.4.3: Apply epoxy glue to the bottom of the box of the next shaft segment ring; S3.4.4: Align the wedge hole of the box of the next shaft segment ring with the hole on the previous shaft segment ring, fix the box of the next shaft segment ring on the previous shaft segment ring, and insert the wedge into the hole on the previous shaft segment ring for reinforced fixation; S3.4.5: Assemble the remaining boxes one by one according to step S3.4.4 until a complete ring is formed; S3.4.6: Repeat steps S3.2.3 to S3.2.7 in step S3.2.

[0012] The slag improver is one or more of fly ash, cement, lime, polymer and fiber.

[0013] The modified slag is obtained by mixing the sandy particles, the fly ash, the cement, the lime and water, wherein the mass of the fly ash is 12-18% of the mass of the sandy particles, the mass of the cement is 4-5% of the mass of the sandy particles, the mass of the lime is 3-10% of the mass of the sandy particles, and the mass of the water is 10-20% of the mass of the sandy particles.

[0014] The admixture is bentonite or polymer.

[0015] The clay particles and the bentonite are mixed to obtain the modified mud, wherein the mass of the bentonite is 5-20% of the mass of the clay particles.

[0016] The advantages of the present invention are: (1) Fiber reinforced plastic (FRP) is used as the material of the supporting structure, and the pipe segments are directly formed by the molding method. This has the advantage of being simple to manufacture and reduces the complex process of traditional reinforced concrete, which requires first tying the steel cage and then pouring concrete. The material is lightweight, and the pipe segment structure is hollow, so it can be transported and constructed using only light equipment or manual labor. Multiple pipe segments can be transported at one time, which improves transportation efficiency and construction speed. It has the advantages of being low-carbon, high-efficiency, reducing labor intensity, and saving manpower and equipment costs. In addition, during the assembly process, the mortise and tenon structure avoids the use of bent bolts, making the assembly of the pipe segments simpler and more secure. (2) The treatment of shaft excavation mud and slag has always been an issue that must be considered in shaft construction. The slag and mud generated, whether they are landfilled or transported and discarded, may cause road pollution and water pollution. Therefore, reusing the shaft excavation mud and slag has certain economic and environmental benefits. The shaft excavation mud is pre-screened and swirl-formed to form coarse aggregate, sand particles and clay particles. The coarse aggregate can be used in the concrete of the shaft bottom, the sand particles can be used to mix cement mortar for wall grouting, the modified sand particles are used to fill the inside of the pipe segment, and the modified clay particles can be used as drag-reducing mud during the shaft sinking process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall assembly of the shaft segment ring of the present invention; Figure 2 It is a schematic diagram of staggered assembly of pipe segments of the present invention; Figure 3 is a three-dimensional diagram of the pipe segment of the present invention (I); Figure 4 is a three-dimensional diagram of the pipe segment of the present invention (II); Figure 5 It is a schematic diagram of the connection between the pipe segments of the present invention; Figure 6 It is a schematic diagram of the interior of the box of the present invention; Figure 7 is a schematic diagram of a cover plate of the present invention; Figure 8 It is a schematic diagram of the installation of the wall back grouting pipeline of the present invention; Fig. 9 for Figure 8 A partial enlarged view of Fig.10 It is a working schematic diagram of the grouting pipeline of the present invention; like Figure 1-10 As shown, the marks in the figure represent respectively: Pipe segment 1, joint seam 2, wedge hole 3, tenon structure 4, mortise structure 5, sealing strip 6, arc box 7, box body 8, cover plate 9, arc vertical plate 10, stiffening rib 11, surrounding rock 12, and grouting pipe behind the wall 13. DETAILED DESCRIPTION

[0018] The features of the present invention and other related features are further described in detail below through embodiments in conjunction with the accompanying drawings to facilitate understanding by those skilled in the art: Example: Figure 1-10 As shown, this embodiment specifically relates to a method for constructing a shaft support segment structure using composite materials and slag, and the method mainly includes the following steps: S1: Make an arc-shaped box body 8 with an open top and a cover plate 9 for closing the top of the box body 8.

[0019] S1.1: The box body 8 is prefabricated by a film pressing method to form a structure with four sides and a bottom closed and an upper opening; S1.2: The exterior of the box 8 is sandblasted, which is beneficial to form a stronger bonding force after contacting with the cement mortar behind the wall; S1.3: The cover plate 9 is prefabricated by a molding method.

[0020] Among them, Figure 1-7 As shown, the inner walls of the two arc vertical plates 10 of the box body 7 are provided with stiffening ribs 11 , and the stiffening ribs 11 are arranged along the arc direction and the vertical direction of the arc vertical plates 10 , and the stiffening ribs 11 are used to enhance the strength of the box body 7 . An arc box 7 is formed between the box body 8 and the cover plate 9. The arc box 7 is made of fiber reinforced composite material (FRP). The FRP material has the advantages of high strength, light weight and corrosion resistance. The arc box 7 is filled with modified slag. The arc box 7 and the modified slag constitute a pipe segment 1. Several pipe segments 1 are circumferentially assembled to form a vertical shaft pipe segment ring. Several vertical shaft pipe segment rings constitute a vertical shaft support pipe segment structure, and splicing seams 2 are formed between circumferentially adjacent pipe segments 1. Adjacent vertical shaft pipe segment rings are staggered. In this embodiment, a total of m vertical shaft pipe segment rings are arranged from bottom to top. The splicing seam 2 of the nth vertical shaft pipe segment ring and the splicing seam 2 of the n+1th vertical shaft pipe segment ring are not at the same vertical position, and the splicing seam 2 of the nth vertical shaft pipe segment ring and the splicing seam 2 of the n+2th vertical shaft pipe segment ring are at the same vertical position.

[0021] The upper and lower ends of the segment 1 (on the cover plate 9 and the bottom of the box body 8) are provided with wedge holes 3 for installing wedges. The number and position of the wedge holes 3 on the upper end of the segment 1 (on the cover plate 9) correspond to the number and position of the wedge holes 3 on the lower end of the segment 1 (the bottom of the box body 8). In this embodiment, two wedge holes 3 are provided on the upper and lower ends of the segment 1 (on the cover plate 9 and the bottom of the box body 8). By installing the wedges in the wedge holes 3, fixation between adjacent vertical shaft segment rings is achieved.

[0022] The two ends of the pipe segment 1 (box 8) are respectively provided with a tenon structure 4 and a mortise structure 5. The circumferentially adjacent pipe segments 1 (box 8) are connected by the cooperation of the tenon structure 4 and the mortise structure 5. The connection of the circumferentially adjacent pipe segments 1 (box 8) is provided with a sealing strip 6. The tenon structure 4 and the mortise structure 5 are both bonded by epoxy adhesive. The convex part of the tenon structure 4 and both sides of the convex part are provided with a sealing strip 6. The groove part of the mortise structure 5 and both sides of the groove part are provided with a sealing strip 6. The number and position of the sealing strips 6 on the tenon structure 4 are respectively corresponding to the number and position of the sealing strips 6 on the mortise structure 5. In this embodiment, the convex part of the tenon structure 4 and both sides of the convex part are respectively provided with a sealing strip 6. The groove part of the mortise structure 5 and both sides of the groove part are respectively provided with a sealing strip 6. The sealing strip 6 is a rubber sealing strip. The sealing strip 6 plays a waterproof role on the one hand, and can resist the stress change caused by thermal expansion and contraction of the material on the other hand.

[0023] S2: The slag slurry generated during shaft excavation is processed, and the coarse aggregate is separated through a pre-screener, the sand particles are separated through a primary cyclone, and the clay particles are separated through a secondary cyclone.

[0024] S2.1: Pre-screen out coarse particles to form coarse aggregate; S2.2: First-stage cyclone screens out sandy particles; S2.3: Collect the sand particles screened by the first-stage cyclone and bring them to the mixing station; S2.4: Add the slag modifier (fly ash, lime, cement, polymer) to the sand particles and mix them thoroughly in the mixing station to obtain modified slag with certain viscosity and strength for standby use; S2.5: Add admixtures (bentonite, polymer) to the clay particles screened by the secondary cyclone to re-formulate the modified mud to meet the strength and fluidity requirements of the back wall grouting, and then set aside; S2.6: The remaining mud after screening and cyclone treatment is circulated to the excavation bin through the slurry inlet pipeline to achieve green recycling of the mud.

[0025] Among them, coarse aggregate and concrete are mixed to obtain bottom concrete, sandy particles and slag modifier are mixed to obtain modified slag, sandy particles and cement mortar are mixed to obtain back-wall cement mortar, and clay particles and admixtures are mixed to obtain modified mud.

[0026] Specifically, the modified slag is obtained by modifying a large amount of waste mud generated during the vertical excavation of mud-water balance, that is, the waste mud is subjected to pre-screening and cyclone screening processes to obtain sandy particles, and a slag modifier is added to the sandy particles to enhance their viscosity and strength, thereby obtaining modified slag, which is used as the filling material inside the pipe segment 1. Specifically, the filling material inside the pipe segment 1 needs to have a certain bonding force and strength to ensure the stability of the structure. Therefore, it is necessary to add a slag modifier to the sandy particles with fluidity that are screened and cyclone-flowed, so as to improve their performance and meet the filling requirements. Common slag modifiers include fly ash, cement, lime, polymers, and fibers. The principle is that the slag modifier reacts chemically with minerals in the soil to produce new substances, such as gelling substances, which can gel and bond soil particles together to form a whole with a certain strength; at the same time, the slag modifier can also fill the pores of the soil, so that the soil particles are graded, the sandy particles are solidified, and the strength of the soil is improved; in addition, the addition of fiber materials can play a reinforcing effect and can also enhance the shear strength of the soil. However, due to the different minerals in the soil composition in different places, the proportion and composition of the slag modifier that needs to be added are also different. Here we only provide the range of slag modifier addition as a reference. After mixing and solidification, the unconfined compressive strength test of the soil is required (strength greater than 0.5MPa) to confirm whether the amount of slag modifier added meets the requirements. It is recommended that the mass of fly ash is 12~18% of the mass of sand particles, the mass of cement is 4~5% of the mass of sand particles, the mass of lime is 3~10% of the mass of sand particles, and the mass of water is 10~20% of the mass of sand particles.

[0027] During the sinking of the shaft segments, lubricating materials (modified mud) behind the wall are required to lubricate them. Clay particles are screened out by cyclone, and admixtures are added for reconfiguration to form modified mud to meet the strength and fluidity requirements of shaft wall grouting. Specifically, bentonite or polymer can be selected as the admixture to enhance the lubrication effect behind the wall. The amount of bentonite added is related to the grouting process and the type of sand. The mass of bentonite is 5-20% of the mass of clay particles. Indoor tests can be carried out before grouting, and the ratio can be confirmed by simulating engineering conditions. Then, by installing friction monitoring equipment between the shaft wall and the formation, the changes in friction during the sinking of the shaft can be monitored in real time, and then it can be judged whether the lubrication effect behind the wall meets the requirements, ensuring that the friction around the horizontal ring shaft is consistent, so as to achieve the effect of uniform sinking. If polymers are added, it is necessary to consider whether environmental protection meets the requirements.

[0028] The shaft support segment structure is installed in the foundation pit, and the wall cement mortar is poured between the shaft support segment structure and the surrounding rock 12 of the foundation pit. The wall cement mortar is obtained by mixing the sand particles screened by the cyclone with the cement mortar. The wall cement mortar is poured through the wall grouting pipe 13, which is installed between the shaft support segment structure and the surrounding rock 12, and the wall grouting pipe 13 is arranged along the circumference of the outer wall of the shaft support segment structure. In this embodiment, the wall grouting pipe 13 is arranged at the joint 2 of the topmost shaft segment ring.

[0029] S3: Excavate the foundation pit and construct the shaft support segment structure using a slurry balance shaft boring machine.

[0030] S3.1: Construction blade foot ring: S3.1.1: Construction preparation: Complete the construction site layout, complete the positioning of the embedded parts of the equipment, confirm the positioning points according to the design drawings, dig 1 to 2 meters downward, complete the casting of the locking ring beam and the construction of the starting well; S3.1.2: Install the blade foot ring: Complete the assembly of the blade foot ring in the launch well; S3.1.3: Install the shaft hoisting system: Connect the steel strands and blade rings to keep the shaft support segment structure in a controlled state.

[0031] S3.2: Install the initial ring of shaft support segment structure: S3.2.1: Apply epoxy glue to the tenon structure 4 and the mortise structure 5 of the box body 8; S3.2.2: Place the opening of the box 8 upward and assemble it in a circular manner, while connecting the box 8 with the blade foot ring; S3.2.3: Fill the modified slag into the box 8 in batches, and the filling thickness each time shall not exceed 20 cm; S3.2.4: Use a vibrating compactor to compact the modified slag in the box 8 to reduce the pores of the modified slag in the box 8 so that the modified slag is evenly distributed; S3.2.5: Repeat steps S3.2.3 and S3.2.4 until the modified slag in the box 8 is filled to the upper surface of the box 8; S3.2.6: Apply epoxy glue on the cover plate 9 and cover it on the box body 9 for gluing; S3.2.7: Use an annular cutter to vertically dig out the modified slag from the wedge hole 3 of the cover plate 9 to form a hole.

[0032] S3.3: Preparation before excavation of slurry balance shaft boring machine: S3.3.1: Complete the installation of the main frame of the shaft boring machine and hoist the shaft boring machine to the starting shaft; S3.3.2: Arrange a fixing base for connecting the shaft boring machine with the segment 1, and connect the supporting arm of the shaft boring machine with the fixing base; S3.3.3: Install the main engine lifting system, pipeline extension system, mud circulation system in sequence, and finally connect the shaft boring machine pipeline and complete the debugging.

[0033] S3.4: Install the remaining rings of the shaft support segment structure: S3.4.1: Excavation of soil by shaft boring machine; S3.4.2: Apply epoxy glue to the cover plate 9 of the upper shaft segment ring; S3.4.3: Apply epoxy glue to the bottom of the box 8 of the next shaft segment ring; S3.4.4: Align the wedge hole 3 of the casing 8 of the next shaft segment ring with the hole on the previous shaft segment ring, and fix the casing 8 of the next shaft segment ring on the previous shaft segment ring, while inserting the wedge into the hole on the previous shaft segment ring for strengthening fixation; S3.4.5: Assemble the remaining boxes 8 one by one according to step S3.4.4 until a complete ring is formed; S3.4.6: Repeat steps S3.2.3 to S3.2.7 in step S3.2.

[0034] S3.5: Fill the space between the shaft support segment structure and the surrounding rock with modified mud, and use the modified mud to assist the shaft support segment structure in sinking: S3.5.1: Install vertical and horizontal monitoring instruments on segment 1 to ensure that the shaft segment does not deviate during construction; S3.5.2: If the geological conditions are good, excavation to a depth of one ring, splicing a ring of support, and sinking a ring of segments 1 may be used; S3.5.3: For soft soil layers prone to settlement, the blade foot ring is first sunk below the tunnel face using a thrust cylinder to achieve advanced support; S3.5.4: During the sinking process, the wall behind segment 1 is filled with modified mud to reduce the sinking resistance and play the role of mud wall protection.

[0035] S3.6: Pour bottom sealing concrete at the bottom of the shaft support segment structure to seal the bottom, and replace the modified mud between the shaft support segment structure and the surrounding rock with cement mortar behind the wall, so that the shaft support segment structure and the surrounding rock form an integral force-bearing structure: S3.6.1: Removal of shaft boring machine and supports; S3.6.2: Determine whether to drive anti-floating anchors into the bottom according to the stress conditions; S3.6.3: Use the pre-screened coarse aggregate to mix concrete and pour the underwater bottom concrete; S3.6.4: If Figure 8-10 As shown in the figure, after the bottom is sealed, the wall grouting pipe 13 is inserted between the surrounding rock 12 and the pipe segment 1, and the wall cement mortar obtained by mixing the sand particles screened by the first-stage cyclone with the cement mortar is pumped in. Fig.10 The back wall grouting pipe 13 moves in the direction a), so that the original modified mud is gradually replaced from bottom to top and backfilled with back wall cement mortar. After solidification, the shaft and the surrounding strata form an integral force-bearing structure; S3.6.5: After the bottom concrete and the cement mortar behind the wall have completely solidified, the mud in the shaft is discharged to complete the construction of the main body of the shaft.

[0036] The beneficial effects of this embodiment are: (1) Fiber reinforced plastic (FRP) is used as the material of the supporting structure, and the pipe segments are directly formed by the molding method. This has the advantage of being simple to manufacture and reduces the complex process of traditional reinforced concrete, which requires first tying the steel cage and then pouring concrete. The material is lightweight, and the pipe segment structure is hollow, so it can be transported and constructed using only light equipment or manual labor. Multiple pipe segments can be transported at one time, which improves transportation efficiency and construction speed. It has the advantages of being low-carbon, high-efficiency, reducing labor intensity, and saving manpower and equipment costs. In addition, during the assembly process, the mortise and tenon structure avoids the use of bent bolts, making the assembly of the pipe segments simpler and more secure. (2) The treatment of mud and debris generated by shaft excavation has always been an issue that must be considered in shaft construction. The debris and mud generated, whether they are landfilled or transported and discarded, may cause road pollution and water pollution. Therefore, reusing the mud and debris has certain economic and environmental benefits. The shaft excavation mud is pre-screened and swirl-formed to form coarse aggregate, sand particles and clay particles. The coarse aggregate can be used in the concrete of the shaft bottom, the sand particles can be used to mix cement mortar for wall grouting, the modified sand particles are used to fill the inside of the pipe segment, and the modified clay particles can be used as drag-reducing mud during the shaft sinking process.

[0037] Although the above embodiments have described the concepts and embodiments of the present invention in detail with reference to the accompanying drawings, ordinary technicians in this field can recognize that various improvements and changes can still be made to the present invention without departing from the scope of the claims, so they are not described one by one here.

Claims

1. A method for constructing a shaft support segment structure using composite materials and slag, characterized in that The method comprises the following steps: S1: manufacturing an arc-shaped box body with an open top and a cover plate for closing the top of the box body; S2: Processing the slag mud generated during shaft excavation, separating the coarse aggregate through the pre-screener, separating the sand particles through the first-stage cyclone, and separating the clay particles through the second-stage cyclone; The coarse aggregate and concrete are mixed to obtain bottom concrete, the sand particles and slag modifier are mixed to obtain modified slag, the sand particles and cement mortar are mixed to obtain back-wall cement mortar, and the clay particles and admixture are mixed to obtain modified mud; S3: Excavate the foundation pit and construct the shaft support segment structure using a slurry balance shaft boring machine; S3.1: Construction blade foot ring; S3.2: Installing an initial ring of the shaft support segment structure; The modified slag is filled in the box and sealed by the cover plate to form segments, and the segments are assembled annularly to form a shaft segment ring; S3.3: Preparation before excavation of the slurry balance shaft boring machine; S3.4: Install the remaining rings of the shaft support segment structure; S3.5: filling the modified mud between the shaft support segment structure and the surrounding rock, and using the modified mud to assist the shaft support segment structure in sinking; S3.6: The bottom sealing concrete is poured at the bottom of the shaft support segment structure to seal the bottom, and the modified mud between the shaft support segment structure and the surrounding rock is replaced by the cement mortar behind the wall, so that the shaft support segment structure and the surrounding rock form an integral force-bearing structure.

2. A method for constructing a shaft support segment structure using composite materials and slag according to claim 1, characterized in that The bottom of the box body and the cover plate are both provided with wedge holes for installing wedges, and the number and positions of the wedge holes on the bottom of the box body correspond to the number and positions of the wedge holes on the cover plate; tenon structures and mortise structures are respectively provided at both ends of the box body, and the circumferentially adjacent boxes are connected by the cooperation of the tenon structures and the mortise structures, and sealing strips are provided at the connections of the circumferentially adjacent boxes.

3. A method for constructing a shaft support segment structure using composite materials and slag according to claim 2, characterized in that The sealing strip is provided on the raised part of the tenon structure and on both sides of the raised part, and the sealing strip is provided on the groove part of the mortise structure and on both sides of the groove part. The number and position of the sealing strips on the tenon structure correspond to the number and position of the sealing strips on the mortise structure.

4. The method for constructing a shaft support segment structure using composite materials and slag according to claim 1, characterized in that The inner walls of the two circular arc vertical plates of the box body are both provided with stiffening ribs.

5. The method for constructing a shaft support segment structure using composite materials and slag according to claim 2, characterized in that The specific steps of step S3.2 are as follows: S3.2.1: Apply epoxy glue to the tenon and mortise structures of the box; S3.2.2: The opening of the box is facing upwards and assembled in a circular manner, and the box is connected to the blade foot ring; S3.2.3: Fill the modified slag into the box in batches, and the filling thickness each time shall not exceed 20 cm; S3.2.4: using a vibrating compactor to compact the modified slag in the box to reduce the pores of the modified slag in the box so that the modified slag is evenly distributed; S3.2.5: Repeat steps S3.2.3 and S3.2.4 until the modified slag in the box body is filled to the upper surface of the box body; S3.2.6: Apply epoxy glue on the cover plate, cover it on the box body, and glue it; S3.2.7: Use an annular cutter to vertically dig out the modified slag from the wedge hole of the cover plate to form a hole.

6. The method for constructing a shaft support segment structure using composite materials and slag according to claim 5, characterized in that The specific steps of step S3.4 are as follows: S3.4.1: Excavation of soil by slurry balance shaft boring machine; S3.4.2: Apply epoxy glue on the cover plate of the shaft segment ring; S3.4.3: Apply epoxy glue to the bottom of the box of the next shaft segment ring; S3.4.4: Align the wedge hole of the box of the next shaft segment ring with the hole on the previous shaft segment ring, fix the box of the next shaft segment ring on the previous shaft segment ring, and insert the wedge into the hole on the previous shaft segment ring for reinforced fixation; S3.4.5: Assemble the remaining boxes one by one according to step S3.4.4 until a complete ring is formed; S3.4.6: Repeat steps S3.2.3 to S3.2.7 in step S3.

2.

7. The method for constructing a shaft support segment structure using composite materials and slag according to claim 1, characterized in that The slag improver is one or more of fly ash, cement, lime, polymer and fiber.

8. The method for constructing a shaft support segment structure using composite materials and slag according to claim 7, characterized in that The modified slag is obtained by mixing the sandy particles, the fly ash, the cement, the lime and water, wherein the mass of the fly ash is 12-18% of the mass of the sandy particles, the mass of the cement is 4-5% of the mass of the sandy particles, the mass of the lime is 3-10% of the mass of the sandy particles, and the mass of the water is 10-20% of the mass of the sandy particles.

9. The method for constructing a shaft support segment structure using composite materials and slag according to claim 1, characterized in that The admixture is bentonite or polymer.

10. A method for constructing a shaft support segment structure using composite materials and slag according to claim 9, characterized in that The clay particles and the bentonite are mixed to obtain the modified mud, wherein the mass of the bentonite is 5-20% of the mass of the clay particles.

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