Basement exterior wall construction method in ultra-narrow foundation trench environment

Abstract

The invention relates to the technical field of basement exterior wall construction, and discloses a basement exterior wall construction method in an ultra-narrow foundation trench environment, which comprises the following steps: constructing a single-side formwork support on the top of a raft plate on the inner side of an exterior wall, transversely fixing a plurality of length-adjustable force transmission supports on the outer side of the single-side formwork support, supporting a pretreatment retaining wall template at the front ends of the force transmission supports, and then pouring a pretreatment retaining wall; a first waterproof coiled material is constructed on the inner side of the pretreated retaining wall in a point bonding mode, and then a reaction bonding type macromolecule wet-laying waterproof coiled material is constructed on the inner side of the first waterproof coiled material; binding an outer wall steel reinforcement framework, assembling an outer wall template and fixing the outer wall template on the single-side formwork support, and then pouring outer wall concrete; under the ultra-narrow foundation trench condition, low construction cost, high construction speed and good construction quality and waterproof effect are achieved, a reference basis is provided for solving similar problems in construction, and green construction is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of basement exterior wall construction, in particular to a basement exterior wall construction method in an ultra-narrow foundation trench environment. Background Art

[0002] In the context of accelerated urban renewal, land resources are becoming increasingly scarce, and the design of underground buildings is getting closer to the planning red line. Faced with the challenges of ultra-deep foundation pits and high water levels, when the underground structure is close to the foundation pit support wall, the exterior wall waterproofing and formwork support of the basement exterior wall construction cannot be constructed by conventional methods.

[0003] When the waterproof construction is carried out in advance, the waterproof base retaining wall construction mostly adopts methods such as repairing plastering and masonry filling on the foundation pit wall, which has a long construction period and has a great impact on the supporting structure. Another method is to implant tension bolts on the pit wall support piles to tie them together as a template for pouring concrete for the waterproof base retaining wall. The Chinese invention patent with publication number CN113373977A discloses a basement exterior wall and its construction method, which is to set reinforcing screws on the support piles, connect lightweight partition boards through the reinforcing screws, and then need to cut off the part of the reinforcing screws exposed outside the lightweight partition boards, and set a waterproof layer on the outside of the partition boards. This method is complex in structure, and the operation method of setting reinforcing screws on the support piles may damage the support structure, which has a great impact on the support structure. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a basement exterior wall construction method under an ultra-narrow foundation trench environment, which achieves lower construction cost, higher construction speed, better construction quality and waterproof effect under ultra-narrow foundation trench conditions, and provides a reference for solving similar problems in construction. The utilization rate of the single-side formwork frame is improved, and at the same time, the workload of workers working in the limited space of the deep and narrow foundation trench is reduced.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] A method for constructing a basement exterior wall in an ultra-narrow foundation trench environment comprises the following steps:

[0007] A single-side formwork frame is constructed on the top of the raft slab inside the outer wall, and a number of adjustable-length force transmission supports are transversely fixed on the outside of the single-side formwork frame. The front end of the force transmission support supports the pre-treated retaining wall template, and then the pre-treated retaining wall is poured;

[0008] The first waterproof membrane is spot-bonded inside the pre-treated retaining wall after demoulding, and then the reaction-bonded polymer wet-laid waterproof membrane is constructed inside the first waterproof membrane;

[0009] The exterior wall reinforcement skeleton is tied, the exterior wall formwork is assembled and fixed on the single-sided formwork frame, and then the exterior wall concrete is poured.

[0010] As a further implementation method, the overlapping seams of the first waterproof membrane and the reaction-bonded polymer wet-laid waterproof membrane are staggered.

[0011] As a further implementation method, the first waterproof membrane is point-bonded to the inner side of the pre-treated retaining wall, the pre-laid cement slurry is not fully scraped, multiple bonding points are scraped on the first waterproof membrane at set intervals, and the first waterproof membrane is paved; the reaction-bonded polymer wet-laid waterproof membrane is fully laid on the first waterproof membrane; the waterproof membrane should be wider than the boundary.

[0012] As a further implementation method, when pouring the pre-treated retaining wall, it should be poured in batches, and the pouring height of each batch must exceed the structural floor by 150mm to 200mm.

[0013] As a further implementation method, according to the combination of accessories corresponding to the height of the designed single-sided formwork frame, a single-sided formwork frame is assembled, each single-sided formwork frame is put in place and laterally connected into one, and at the same time, the single-sided formwork frame is fixed by cooperating with a splint-type pull rod and an embedded pull ring.

[0014] As a further implementation method, the force transmission support includes a short steel pipe and an adjustable support, one end of the adjustable support is threadedly matched with the short steel pipe, and a channel steel is arranged at one end of the short steel pipe away from the adjustable support.

[0015] As a further implementation method, the channel steel is fixed to the vertical rib of the single-sided formwork frame by hook bolts and gaskets; each force transmission support member is connected into a whole by steel pipes in the longitudinal and transverse directions.

[0016] As a further implementation method, before the exterior wall formwork is constructed, the protective film of the reaction-bonded polymer wet-laid waterproofing membrane facing the exterior wall concrete surface must be removed, and then the exterior wall formwork is assembled.

[0017] As a further implementation method, when the wall retaining formwork is removed, the single-sided formwork frame can be moved back by using a tower crane. When the exterior wall formwork is installed, the single-sided formwork frame can be re-positioned by using a tower crane, and the vertical ribs of the single-sided formwork frame can be tied to the main ribs of the exterior wall formwork with hook bolts and gaskets to form a whole.

[0018] As a further implementation method, the single-sided formwork frame is composed of a ladder frame and a diagonal brace on the top of the ladder frame, and an adjusting screw is provided at the inner end of the bottom of the ladder frame for adjusting the verticality of the vertical ribs of the single-sided formwork frame.

[0019] The beneficial effects of the present invention are as follows:

[0020] The present invention sets a pre-treated retaining wall on the inner side of the foundation pit support structure, and constructs the waterproof layer originally attached to the outer side of the outer wall on the pre-treated retaining wall, so that the pre-constructed waterproofing coiled material is "point-bonded" to the pre-treated retaining wall; it reacts and bonds with the outer wall structure, and utilizes the physical and chemical reaction of the reaction-bonded polymer wet-laid waterproofing coiled material and cement slurry to make the waterproof layer and the outer wall of the basement become a whole, so as to achieve a skin-like waterproof structure and improve waterproof safety; the single-sided formwork frame set on the inner side of the outer wall serves as a reinforcement mechanism for the single-sided formwork of the outer wall of the basement, and also as a template reinforcement mechanism for pouring the pre-treated retaining wall, so as to achieve one-time assembly and two-time use; the horizontal side pressure of the pre-treated retaining wall template is transmitted to the single-sided formwork frame by adding a force transmission support, so as to meet the function of reinforcing the template. It realizes the construction cost at a lower level, the construction speed at a higher level, the construction quality and the waterproofing effect at a lower level under the condition of an ultra-narrow foundation trench, and provides a reference basis for solving similar problems in construction.

[0021] The present invention improves the utilization rate of the single-sided formwork, and at the same time, reduces the workload of workers working in the limited space of the deep and narrow foundation pit, shortens the existence time of the deep and narrow foundation pit, reduces safety risks, reduces workers' labor, creates conditions for improving the utilization rate of land within the red line, and realizes green construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0023] Figure 1 It is a schematic diagram of using a single-side formwork frame and a force transmission support to construct a pre-treatment retaining wall in an embodiment of the present invention;

[0024] Figure 2 is a schematic diagram of using a single-side formwork frame to construct an exterior wall in an embodiment of the present invention;

[0025] Figure 3 It is a schematic structural diagram of a force transmission support in an embodiment of the present invention.

[0026] In the figure: the distances or sizes between parts are exaggerated to show the positions of various parts, and the schematic diagram is for reference only.

[0027] Among them: 1. Single-sided formwork, 2. Raft, 3. Ground beam, 4. Pre-treated retaining wall, 5. Force transmission support, 6. Embedded tie rod, 7. External wall, 8. Reaction-bonded polymer wet-laid waterproof membrane; 11. Short diagonal brace, 12. Long diagonal brace, 13. Adjustment screw; 51. Short steel pipe, 52. Adjustable support, 53. Channel steel. DETAILED DESCRIPTION

[0028] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0029] Embodiment 1

[0030] In a typical embodiment of the present invention, reference is made to Figure 1-Figure 3 As shown, a method for constructing a basement exterior wall in an ultra-narrow foundation trench environment comprises the following steps:

[0031] Step (1): Pre-treatment of ground beam construction.

[0032] Step (2): Waterproof construction of the bottom and sides of the raft.

[0033] Step (3): Construction of raft slab and upward guide wall.

[0034] Step (4): construct a single-sided formwork frame on the top of the raft slab inside the outer wall, and laterally fix a number of adjustable-length force-transfer supports on the outside of the single-sided formwork frame. The front end of the force-transfer supports supports the pre-treated retaining wall template, and then casts the pre-treated retaining wall to achieve step-by-step construction of the pre-treated retaining wall according to height.

[0035] Step (5): construct a waterproof layer on the inner side of the pre-treated protective wall after demolding, spot-bond the first waterproof membrane on the inner side of the pre-treated protective wall, and then construct a reaction-bonded polymer wet-laid waterproof membrane on the inner side of the first waterproof membrane.

[0036] Step (6): exterior wall and floor slab construction, exterior wall reinforcement skeleton binding, exterior wall formwork assembly and fixing on the single-sided formwork frame, and then pouring exterior wall concrete.

[0037] Step (7): Construction of the next floor, looping steps (4) to (6).

[0038] By using the single-sided formwork frame 1 set on the inner side of the outer wall 7 as a formwork support, the pre-treated retaining wall 4 is first cast on the outer side of the outer wall inside the pit wall, and the outer wall waterproofing is constructed in advance on the pre-treated retaining wall 4. The waterproofing membrane adopts a reactive bonding polymer wet-laid waterproof membrane 8 that can react with cement slurry. Then, the single-sided formwork frame 1 is used to support the outer wall formwork to cast the basement outer wall 7. Among them, the horizontal load during the retaining wall casting is transmitted by setting a force transmission support 5 between the single-sided formwork frame 1 and the pre-treated retaining wall formwork.

[0039] Specifically, in step (1), for the pre-treatment of the ground beam construction:

[0040] First, the cushion layer is constructed in the foundation pit. After the cushion layer is constructed, the ground beam 3 is constructed outside the raft slab. Figure 1As shown, the ground beam 3 should be at least 100 mm higher than the supporting steel waist beam and at least 150 mm higher than the horizontal construction joint of the outer wall.

[0041] like Figure 1 As shown, the ground beam 3 serves as the outer formwork of the raft 2 and also as a structure supporting the upper pre-processed retaining wall 4. Most of the deadweight load of the pre-processed retaining wall 4 is transferred to the outer expansion part of the raft 2 through the inverted L-shaped cantilever structure.

[0042] The casting height of the ground beam 3 is slightly higher than the steel waist beam of the supporting structure and higher than the horizontal joint of the outer wall (the top of the guide wall on the raft slab), in order to reduce the adverse effects of the construction of the pre-treated retaining wall 4 on the supporting waist beam (anchor cable) and to facilitate the construction of the outer side of the raft slab 2 for waterproofing.

[0043] The conventional processes such as positioning and laying out, steel bar binding, and formwork support in the construction of components such as ground beams, retaining walls, and exterior walls will not be repeated in this method.

[0044] In step (2):

[0045] The waterproof construction of the side wall includes the waterproof construction of the retaining wall beam 3 and the waterproof construction of the pre-treated retaining wall 4. The waterproof construction of the retaining wall beam 3 is described as an example. In this method, two layers of reactive self-adhesive polymer wet-laid waterproofing membrane 8 are used for waterproofing on the side and the bottom of the board. Wet-laid waterproofing membrane is to scrape cement slurry made according to the manufacturer's required proportion on the part that needs to be bonded, and then lay the reactive self-adhesive polymer membrane, while removing the protective film of the bonding part. During the construction process, the laid membrane is scraped and pressed flat with a scraper to ensure firm adhesion.

[0046] 1. After removing the concrete formwork of ground beam 3, check and clean the sharp corners and burrs on the surface, and repair them to make them smooth.

[0047] 2. The first waterproofing is done by the "point sticking method". That is, when the first waterproofing is done, the pre-laid cement slurry is not fully scraped, and 200mm×200mm bonding points are scraped at a spacing of 1m×1m, and the first waterproofing membrane is laid and glued.

[0048] 3. After the first waterproofing membrane is constructed, the second waterproofing membrane is fully laid 24 hours after the first waterproofing membrane is constructed. The overlap between the second waterproofing membrane and the first waterproofing membrane is staggered by half width. The second waterproofing membrane adopts a reactive self-adhesive polymer wet-laid waterproofing membrane 8. The first waterproofing membrane can adopt a reactive self-adhesive polymer wet-laid waterproofing membrane 8 or an ordinary waterproofing membrane. The first waterproofing membrane of this embodiment adopts an ordinary SBS waterproofing membrane.

[0049] 4. The overlapping length of waterproofing membrane should not be less than 80mm, and the overlapping parts should be tightly bonded. The first waterproofing layer should be 500mm wide outside the construction boundary; the second waterproofing membrane should be 300mm wide outside the construction boundary. The protective film on both sides of the overlapping part of the membrane should be retained.

[0050] 5. During the second waterproofing construction, keep the protective film facing the pit and remove it after the raft 2 or the basement exterior wall reinforcement is tied. Protective layer pads are set on the outside of the exterior wall reinforcement according to the actual size, and the spacing between the pads in a plum blossom shape is not greater than 500mm.

[0051] Waterproof construction of raft bottom:

[0052] 1. Before waterproofing the bottom of the raft, the pits and protrusions on the top of the cushion layer should be cleaned and repaired, and R-arc fillets should be applied to the corners.

[0053] 2. First, apply additional layers of roll material at corners and other locations. The width of the additional layer is 500mm.

[0054] 3. The first waterproofing is done in an "empty" manner. That is, the first waterproofing membrane is not bonded to the cushion layer, but the overlap of the waterproofing membrane should be no less than 80mm, and the overlap should be tightly bonded.

[0055] 4. 24 hours after the first waterproofing membrane is applied, the second waterproofing membrane should be fully applied. The overlap between the second and first waterproofing membranes should be staggered by half width.

[0056] 5. Pour a 20mm thick cement mortar waterproof protective layer 24 hours after the construction of the bottom waterproof membrane of the slab is completed, and the protective film of the membrane is removed as it is poured.

[0057] Pre-embedded pull ring:

[0058] 1. After the reinforcement of the raft 2 or floor slab is tied, the embedded pull ring 6 should be set near the inner corner of the external wall guide wall according to the calculation requirements of the single-sided formwork setting plan. The embedded pull ring 6 should be set strictly according to the spacing required by the construction plan and kept in a straight line parallel to the external wall. The embedded pull ring 6 is about 50mm higher than the raft concrete surface, which is convenient for setting the clamping plate type tie rod to tie the single-sided formwork 1.

[0059] 2. Because the embedded pull ring 6 cannot be spot welded directly to the main reinforcement of the structure, in order to ensure that the embedded parts do not move or shift during concrete pouring, it is required to add additional steel bars at the corresponding positions, and the embedded pull ring 6 is spot welded on the additional steel bars. When spot welding, please be careful not to damage the effective diameter of the embedded parts.

[0060] 3. Conventional municipal single-sided formwork embedded parts use straight bar tie rods. Considering that the construction project is generally small in quantity and the interval between processes is short, in order to ensure the anchoring force of the embedded parts, this method recommends the use of "J"-shaped pre-embedded tie rings. After the pre-embedded tie rings 6 are completed, the raft 2 structure is cast to complete step (3).

[0061] In step (4):

[0062] First pre-treat the wall protection mold:

[0063] 1. Configure a single-side template for the pre-treated retaining wall 1. In order to reduce the impact of the pouring construction of the pre-treated retaining wall 1 on the anchor cables and waist beams of the original supporting structure, the pouring height of each step should be 100mm higher than the horizontal steel waist beam. According to the construction progress of the underground structure layer, the pouring height of each batch should be 150mm to 200mm higher than the structural floor (including the height of the upper guide wall on the outer wall).

[0064] 2. The specifications and spacing of the secondary ribs and the specifications and spacing of the main ribs of the formwork should be designed and verified based on the single-sided supported wall formwork support model.

[0065] 3. Single-sided formwork can be steel formwork or wooden formwork. Single-sided formwork is no longer reinforced with tension bolts. The formwork, wooden secondary ribs and steel pipe main ribs are connected as a whole by wire or hook bolts to ensure the positional relationship between them.

[0066] 4. The boundary of the retaining wall concrete is set back 30mm to 50mm from the outer skin of the basement exterior wall, which reduces the mutual influence between the retaining wall formwork and the exterior wall steel skeleton, and also reduces the influence of the steel skeleton on the waterproof membrane when pouring the exterior wall concrete.

[0067] Assembling the one-sided formwork reinforcement system:

[0068] 1. Assemble a single formwork frame according to the combination of accessories corresponding to the height of the designed single-sided formwork frame. According to the spacing and positioning of the designed single-sided formwork frame 1, put each single-sided formwork frame in place, and use steel pipes and buckles to connect multiple formwork frames horizontally into one. Use the support pressure beam, splint-type tie rod and butterfly nut to reliably tie the formwork frame to the embedded pull ring. The splint-type tie rod should be vertical to the pressure beam, and the butterfly nuts of each tie rod should be tightened to the same degree.

[0069] 2. The back ribs at the front end of the reinforcement system should be straightened to ensure the horizontal flatness of the template.

[0070] 3. When a single combined bracket is high, in order to prevent the bracket from overturning and causing safety accidents during assembly, the lowest bracket can be placed in place according to the designed position and spacing. After the front back rib is straightened, the formwork frame and the embedded pull ring are reliably tied with a pressure beam, a pull rod and a butterfly nut. Then, use a steel pipe and a buckle to connect them horizontally into one. Then, connect the upper bracket of each bracket layer by layer. After each section is completed, straighten and level it, and tie it horizontally.

[0071] like Figure 2 As shown, the single-sided formwork frame 1 is triangular in shape as a whole, including a ladder frame at the bottom, a diagonal support base is provided at the rear end of the top of the ladder frame, a short diagonal support 11 and a long diagonal support 12 are connected through the diagonal support base, and supporting ribs are installed outside the short diagonal support 11 and the long diagonal support 12 to support the formwork. An adjusting screw rod 13 is provided at the rear end of the bottom of the ladder frame to facilitate the adjustment of the verticality.

[0072] Set the force transmission support 5 and the template vertical flatness adjustment:

[0073] According to the on-site working conditions, the single-side formwork frame 1 needs to be set on the top of the raft 2 inside the outer wall 7, and the formwork frame vertical ribs (support ribs) are about 850mm away from the outer pre-treated wall template. The force of the template main ribs (horizontal double steel pipes) cannot directly act on the vertical ribs of the formwork frame, so the force transmission support 5 is used to transfer the horizontal load.

[0074] like Figure 3 As shown, the force transmission support 5 includes a short steel pipe 51, an adjustable support 52 and a channel steel 53. One end of the adjustable support is threadedly matched with the short steel pipe, and the channel steel 53 is arranged at one end of the short steel pipe 51 away from the adjustable support 52.

[0075] A short steel pipe 51 (or a vertical rod of a buckle frame) with a length of 500 mm is combined with an adjustable top support 52 to form a force transmission support 5 with adjustable length. The front end of the force transmission support 5 is supported on the main rib of the template (horizontal double steel pipe), and the rear end is supported on the vertical rib of the support frame. In order to prevent the rear end of the force transmission support from sliding and failing, a 6.5# small channel steel is set horizontally on the vertical rib of the force transmission support. The horizontal small channel steel 53 is fixed on the vertical rib of the bracket with hook bolts and washers.

[0076] In order to ensure that the position of the force transmission support is accurate and firm, each force transmission support is connected as a whole by steel pipes (or buckle frame tie rods) vertically and horizontally. By adjusting the adjustment screw 13 at the rear end of the formwork frame, the verticality of the vertical ribs of the single-sided formwork frame 1 can be adjusted. After the pre-treated retaining wall 4 formwork is installed with the single-sided formwork frame, the pre-treated retaining wall concrete is poured. The pre-treated retaining wall concrete should be poured in sections according to the height in strict accordance with the plan, and the super-high construction should not be carried out at one time. During the pouring of the pre-treated retaining wall concrete, the feed port should be as close as possible to the steel support waist beam at the top of the formwork, and vibrating rods and other auxiliary materials should be used in time to reduce the accumulation of concrete on the waist beam. During the pouring process, the collision and influence of vibrating rods and other supporting structures such as waist beams and anchor cables should be reduced as much as possible.

[0077] After that, the retaining wall formwork is removed. After the retaining wall concrete is poured, the force transmission support is removed and the retaining wall formwork is removed. The single-sided formwork frame that has been reinforced into an integral whole can be split into groups of 4-5 frames in order to be reused in the reinforcement of the exterior wall formwork. The lower pressure beam and splint-type tie rod are removed and lifted about 1m away from the exterior wall by a tower crane to facilitate waterproofing construction, steel bar binding, and exterior wall inner side formwork.

[0078] In step (5), two layers of waterproof membranes should be constructed on the inner side of the pretreated protective wall 4, that is, the first waterproof membrane is point-bonded on the inner side of the pretreated protective wall, and then the reaction-bonded polymer wet-laid waterproof membrane is constructed on the inner side of the first waterproof membrane. The first waterproof membrane is point-bonded on the inner side of the pretreated protective wall, and the pre-laid cement slurry is not fully scraped. A plurality of bonding points are scraped on the first waterproof membrane at a set interval, and the first waterproof membrane is paved; the reaction-bonded polymer wet-laid waterproof membrane is fully laid on the first waterproof membrane; the waterproof membrane should be wide beyond the boundary.

[0079] In step (6):

[0080] After the construction of the waterproof membrane is completed, the external wall steel frame is tied. Before the external wall formwork is constructed, the protective film of the reaction-bonded polymer wet-laid waterproof membrane facing the external wall concrete surface must be removed, and then the external wall formwork can be assembled.

[0081] According to the design plan of the external wall formwork, the formwork is assembled and the secondary ribs are placed in place. Because the height of the external wall 7 is inconsistent with the height of the wall casting, the inner formwork of the external wall 7 needs to be re-formed according to the plan. The formwork, the secondary ribs of the wooden square and the main ribs of the steel pipe are connected as a whole by iron wire or hook bolts to ensure the positional relationship between them.

[0082] Use a tower crane to reposition the formwork support frame that was removed when the wall formwork was dismantled. Use the support pressure beam, tie rod and butterfly nut to securely tie the formwork support frame to the embedded pull ring. Use hook bolts and gaskets to tie the support vertical ribs and the formwork main ribs (double steel pipes) into a whole.

[0083] The main ribs of the single-sided formwork frame are adjusted and assembled according to the designed height and composition, and then re-stretched into a whole. The vertical ribs of the formwork frame also need to be appropriately adjusted according to the plan. In order to reduce the workload of dismantling and modification, the formwork frame is generally arranged with the smaller value of the spacing required for the single-sided formwork of the retaining wall and the inner wall during the design of the plan. The lower bracket of each formwork frame is not replaced, and only the upper vertical ribs are replaced or increased or decreased.

[0084] Adjust the vertical flatness of the single-sided formwork frame and the external wall formwork. Adjust the verticality of the bracket by adjusting the screw foot at the rear end of the formwork frame. When a single-sided formwork frame with a diagonal tie rod triangular support structure is used, the verticality of the bracket can be adjusted by adjusting the length of the diagonal tie rod.

[0085] Pour the exterior wall concrete. After the formwork is set up, pour the exterior wall concrete according to the design and relevant regulations.

[0086] The exterior wall formwork can be removed after the exterior wall concrete pouring reaches the formwork removal conditions.

[0087] 1. Remove the horizontal steel pipes that are tied horizontally on the single-side formwork frame. In order to reduce the workload of disassembling and assembling the formwork frame, the formwork frames can be grouped and hoisted to the stacking site, and left for direct use in groups in the next construction section.

[0088] 2. Remove the main steel pipe ribs and secondary wooden ribs of the exterior wall formwork.

[0089] 3. Remove the exterior wall formwork.

[0090] After removing the exterior wall formwork, the top slab is constructed, and then the next layer of retaining concrete wall is constructed in a cyclic manner, i.e. step (7).

[0091] In this embodiment, a pre-treated retaining wall is arranged on the inner side of the foundation pit supporting structure, and the waterproof layer originally attached to the outer side of the outer wall is constructed on the pre-treated retaining wall, and the waterproof roll constructed in advance is connected to the pre-treated retaining wall by "spot bonding"; it is reactively bonded with the outer wall structure, and the physical and chemical reaction of the reactive bonding polymer wet-laid waterproofing roll material and cement slurry is utilized to make the waterproof layer and the outer wall of the basement become a whole, so as to achieve a skin-type waterproof structure and improve waterproof safety; the single-sided formwork frame 1 arranged on the inner side of the outer wall serves as a reinforcement mechanism for the single-sided formwork of the outer wall of the basement, and is also used for the template reinforcement mechanism for the pouring of the pre-treated retaining wall, thereby realizing one-time assembly and two uses.

[0092] The horizontal side pressure of the pre-treated wall protection template is transmitted to the single-sided formwork frame by adding a force transmission support 5, so as to meet the function of reinforcing the template. This embodiment realizes the "ultra-narrow foundation trench" condition with lower construction cost, higher construction speed, better construction quality and waterproof effect, and provides a reference for solving similar problems in construction. The utilization rate of the single-sided formwork frame is improved, and at the same time, the workload of workers working in the limited space of the deep and narrow foundation trench is reduced.

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for constructing basement exterior walls in an ultra-narrow foundation trench environment, characterized in that: The steps include: A single-side formwork frame is constructed on the top of the raft slab inside the outer wall, and a number of adjustable-length force transmission supports are transversely fixed on the outside of the single-side formwork frame. The front end of the force transmission support supports the pre-treated retaining wall template, and then the pre-treated retaining wall is poured; The first waterproof membrane is spot-bonded inside the pre-treated retaining wall after demoulding, and then the reaction-bonded polymer wet-laid waterproof membrane is constructed inside the first waterproof membrane; The exterior wall reinforcement skeleton is tied, the exterior wall formwork is assembled and fixed on the single-sided formwork frame, and then the exterior wall concrete is poured.

2. The method for constructing basement exterior walls in an ultra-narrow foundation trench environment according to claim 1, characterized in that: The overlapping seams of the first waterproofing membrane and the reaction-bonded polymer wet-laid waterproofing membrane are staggered.

3. The method for constructing basement exterior walls in an ultra-narrow foundation trench environment according to claim 1, characterized in that: The first waterproof membrane is point-bonded to the inner side of the pre-treated retaining wall, the pre-laid cement slurry is not fully scraped, a plurality of bonding points are scraped on the first waterproof membrane at set intervals, and the first waterproof membrane is paved; the reaction-bonded polymer wet-laid waterproof membrane is fully laid on the first waterproof membrane; the waterproof membrane should be wider than the boundary.

4. The method for constructing basement exterior walls in an ultra-narrow foundation trench environment according to claim 1, characterized in that: When pouring the pre-treated retaining wall, it should be poured in batches, and the pouring height of each batch must exceed the structural floor by 150mm to 200mm.

5. The method for constructing basement exterior walls in an ultra-narrow foundation trench environment according to claim 1, characterized in that: According to the combination of accessories corresponding to the designed height of the single-sided formwork frame, assemble the single-sided formwork frames, put each single-sided formwork frame in place and connect them horizontally into one, and at the same time fix the single-sided formwork frames through the cooperation of the splint-type pull rod and the embedded pull ring.

6. The method for constructing basement exterior walls in an ultra-narrow foundation trench environment according to claim 1, characterized in that: The force transmission support comprises a short steel pipe and an adjustable support, one end of the adjustable support is threadedly matched with the short steel pipe, and a channel steel is arranged at one end of the short steel pipe away from the adjustable support.

7. The method for constructing basement exterior walls in an ultra-narrow foundation trench environment according to claim 6, characterized in that: The channel steel is fixed on the vertical rib of the single-side formwork frame through hook bolts and gaskets; each force transmission support member is connected into a whole through steel pipes in the longitudinal and transverse directions.

8. The method for constructing basement exterior walls in an ultra-narrow foundation trench environment according to claim 1, characterized in that: Before the exterior wall formwork is constructed, the protective film of the reaction-bonded polymer wet-laid waterproofing membrane facing the exterior wall concrete surface must be removed, and then the exterior wall formwork can be assembled.

9. The method for constructing basement exterior walls in an ultra-narrow foundation trench environment according to claim 8, characterized in that: When the wall protection formwork is removed, the single-sided formwork frame can be moved back by using a tower crane. When the exterior wall formwork is installed, the single-sided formwork frame can be repositioned by using a tower crane, and the vertical ribs of the single-sided formwork frame can be tied to the main ribs of the exterior wall formwork with hook bolts and gaskets.

10. The method for constructing basement exterior walls in an ultra-narrow foundation trench environment according to claim 1, characterized in that: The single-sided formwork frame is composed of a ladder frame and a diagonal brace on the top of the ladder frame. An adjusting screw is provided at the inner end of the bottom of the ladder frame for adjusting the verticality of the vertical ribs of the single-sided formwork frame.

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