JP4821713B2 - Synthetic wall structure and method for constructing synthetic wall - Google Patents

Description

  The present invention relates to a composite wall structure in which a steel earth retaining wall and a post-cast reinforced concrete wall are integrated, and a method for constructing the same. The present invention has a drainage route for groundwater leaking from a steel earth retaining wall, and a mold for concrete placement. The present invention relates to a structure suitable for an underground structure such as an underground wall or an open-cut tunnel of a building that requires a waterproof property that does not require a frame and is easy to construct.

  When constructing an underground structure such as an underground outer wall of a building or an open-cut tunnel, it is common practice to prevent the earth and sand from collapsing with a retaining wall to secure a work space, and various prior arts are disclosed.

  When a soil cement column wall is used as a retaining wall, it is proposed that a slip stopper is attached to the core material (mainly H-shaped steel is used) and integrated with a post-cast reinforced concrete wall (Patent Document) 1, Patent Document 2, etc.).

  When steel pipe sheet pile walls and steel sheet pile walls are used as the retaining wall, the steel sheet pile is backfilled after the construction of the underground structure, but the effect of the surrounding ground subsidence by pulling the steel sheet pile, etc. If it is expected, it will be buried underground.

  In such a case, it has been proposed to use a hat-shaped steel sheet pile as a steel sheet pile, attach a shear connector such as a stud and integrate it with post-cast reinforced concrete, and effectively use it as part of the frame of an underground structure. (Patent Document 3, Patent Document 4, etc.).

  In addition, when constructing a basement wall, the basement wall may be lower than the groundwater level, and groundwater may enter through gaps in the wall, or condensation may occur due to temperature differences between the inside and outside of the floor, resulting in condensation on the floor surface. Accumulation occurs.

  Steel pipe sheet piles and steel sheet pile joints are water-stopped, but if there is a large earthquake during the use of an underground structure, the fitting state of the joints changes and the water stoppage is lost. Cracks occur in reinforced concrete walls, and groundwater enters.

  In order to prevent this, a waterproof layer is provided outside the underground wall, or a wall is further provided inside the underground wall to use a gap as a drainage channel as a double wall structure. However, the method of providing a double wall by further providing a wall inside the underground wall inevitably increases the wall thickness, thereby reducing the effective space. Moreover, when a waterproof layer is provided outside the underground wall, the amount of excavated soil increases and the construction cost increases.

In Patent Document 5, a corrugated plate-like member having water-stopping properties is provided outside the underground wall to form a waterproof structure, and at the same time, an air heat insulating layer is formed between the underground wall and the plate-like member for the purpose of preventing condensation. And the structure utilized as a vertical drainage channel is described.
Japanese Patent No. 710393 JP 58-29922 A JP-A-61-87015 Japanese Patent Laid-Open No. 7-310365 Japanese Patent No. 1331527

  By the way, when a hat-shaped steel sheet pile wall is used as the retaining wall, when a reinforced concrete is constructed on the front surface of the wall, a formwork is required to cover the hollow portion so that the concrete does not surround the hollow portion.

  However, since the hollow portion is narrow and it is difficult to release the mold after the concrete is hardened, and the used mold cannot be collected, so it must be a discarded mold.

  On the other hand, if the formwork is not used and the hat-shaped steel sheet pile wall itself is used as the formwork and the cavity is filled with concrete, the concrete functions as a structural material in a stress state where the steel sheet pile side is pulled. The benefits are small just by increasing the amount of reinforced concrete material used. Further, the hollow portion cannot be used as a drainage channel or heat insulation layer for water leakage from the joint.

  Then, an object of this invention is to provide the synthetic | combination wall structure using the hat-shaped steel sheet pile which solves the problem mentioned above, and the construction method of the synthetic | combination wall.

The object of the present invention can be achieved by the following means.
1. A composite wall structure in which a steel earth retaining wall and a post-cast reinforced concrete wall are integrated with a stud provided on a contact surface of the steel earth retaining wall with the post-cast reinforced concrete wall,
The steel earth retaining wall is configured by connecting a hat-shaped steel sheet pile or a Z-shaped steel sheet pile fitted with two pieces so as to form a hat-shaped cross section in advance,
When the steel sheet pile of the steel retaining wall is a hat-type steel sheet pile, the post-cast reinforced concrete wall is placed with concrete in a straight line over the flange portion and fitted with two pieces so as to make a hat-shaped cross section in advance. In the case of the combined Z-shaped steel sheet pile, it is constructed by placing concrete substantially linearly over the wall surface including the fitting part,
A region surrounded by the steel retaining wall and the post-cast reinforced concrete wall is a cavity, and a discharge path for discharging leaked groundwater to the outside of the post-cast reinforced concrete wall is provided at the bottom of the cavity. Synthetic wall structure.
2. 1. The composition according to 1, wherein a joint portion of a hat-shaped steel sheet pile for constructing a steel retaining wall or a Z-shaped steel sheet pile fitted in advance so as to form a hat-shaped cross section is water-stopped. Wall structure.
3. The inside of the cavity includes a hat-shaped steel sheet pile , or a joint portion of a Z-shaped steel sheet pile fitted with two pieces so as to form a hat-shaped cross section in advance , and a cutout portion that conducts to a discharge path provided on the bottom surface of the cavity 3. A synthetic wall structure according to claim 1 or 2, which is filled with a foamed polystyrene mold.
4). 4. The synthetic wall structure according to 3, wherein the polystyrene foam form is divided into a plurality in the height direction.
5). The foamed polystyrene frame is inserted into the cutout portion in the vertical direction, the lower end is fixed to the bottom surface of the cavity, and the upper end is a wire rope having an end plate in contact with the upper surface of the expanded polystyrene frame, The composite wall structure according to 3 or 4, wherein the composite wall structure is fixed to a bottom surface of the cavity.
6). After building a steel retaining wall by placing a hat-shaped steel sheet pile or a Z-shaped steel sheet pile with two joints fitted in advance so as to form a hat-shaped cross section, excavating the soil on the front, A stud is welded to the planned contact surface of the earth retaining wall with the post-cast reinforced concrete wall, and a discharge path is formed on the bottom surface of the planned cavity between the steel earth retaining wall and the post-cast concrete wall, and then the drain path is A composite wall construction method comprising constructing a post-cast reinforced concrete wall by placing concrete in a substantially straight line along the planned contact surface so as not to be buried.
7). 7. A synthetic reinforced concrete wall according to claim 6, wherein after forming a discharge path on the bottom surface of the planned cavity portion, a foamed polystyrene formwork is disposed in the planned cavity portion, and then concrete is placed to construct a post-cast reinforced concrete wall. How to build a wall.
8). 8. The method for constructing a synthetic wall according to claim 7, wherein the foamed polystyrene frame has a notch including a joint of a hat-shaped steel sheet pile or a Z-shaped steel sheet pile.
9. 9. The method for constructing a synthetic wall according to claim 8, wherein the polystyrene foam form is divided into a plurality in the height direction.
10. The foamed polystyrene mold is fixed to the bottom of the cavity with a wire rope having an end plate in contact with the top surface of the foamed mold frame at the upper end. How to construct a synthetic wall.
11. The composite wall according to any one of 11.1 to 5 is used as a wall surface, and has a waterproof layer connected to a steel retaining wall below the composite reinforced concrete wall of the composite wall, A drainage structure is provided in which a discharge path for discharging groundwater leaking into a cavity between the post-cast reinforced concrete wall and the steel earth retaining wall is provided.
12. The steel retaining wall is constructed of a hat-shaped steel sheet pile or a Z-shaped steel sheet pile fitted with a joint so as to have a hat-shaped section in advance, and a hat-shaped steel sheet pile or a joint having a hat-shaped section in advance. The underground structure according to 11, wherein a foamed polystyrene frame having a cutout portion including a joint portion of a Z-shaped steel sheet pile fitted in the portion is provided in the cavity.
13. The underground structure according to 12, wherein the polystyrene foam is divided into a plurality in the height direction.
14. A wire rope having an end plate in which the foamed mold frame is vertically inserted through the notch, the lower end is fixed to the bottom surface of the cavity, and the upper end is in contact with the upper surface of the polystyrene mold The underground structure according to 12 or 13, wherein the underground structure is fixed to a bottom surface of the cavity.

According to the present invention, the following effects can be obtained, which is extremely useful industrially.
1. As a steel retaining wall, a hat-shaped steel sheet pile in which the joint is located at the outermost edge from the neutral shaft and two Z-sheet steel sheet piles that are pre-fitted and then welded are used, and the joints of these steel sheet piles are post-cast reinforced concrete By disposing the space between the steel sheet pile and the reinforced concrete wall on the side far from the wall as a cavity and not having the joint part and the reinforced concrete wall in direct contact with each other, the fitting state of the joint can be changed. It is possible to suppress the cracking of the accompanying concrete wall.

  2. When the synthetic wall according to the present invention is used for the basement wall surface, the drainage structure provided on the bottom surface of the cavity allows the water flowing into the cavity to be drained quickly even if water leaks from the steel sheet pile joint. Water pressure does not act on the reinforced concrete wall. The cavity serves as a heat insulation layer to suppress dew condensation inside the underground wall, and the moisture condensed inside the cavity is drained from the lower end, so that the inside of the underground wall is not adversely affected.

  3. When placing the steel earth retaining wall into the void between the inner side of the steel earth retaining wall and the planned construction part of the reinforced concrete wall, when placing the concrete to integrate the steel earth retaining wall with the post-cast concrete wall, The formwork installation work on the steel sheet pile side can be carried out easily and economically.

  4). Leakage from the steel sheet pile joints travels through the cutouts in the polystyrene foam formwork and drains into the drainage of the waterproof layer, so water leaks from the walls even if a crack occurs in the reinforced concrete due to a large earthquake, etc. do not do. Moreover, although it is partial, the heat insulation effect is acquired and the dew condensation in a underground wall is suppressed.

  The present invention uses a trapezoidal cross-section cavity formed between a steel retaining wall using a hat-shaped steel sheet pile and a post-cast reinforced concrete wall as a drainage channel or heat insulation layer for water leakage from the joint, and In order to improve the workability of post-cast reinforced concrete walls and improve drainage and heat insulation, it is necessary to fill the hollow portion with foamed polystyrene with a hollow at the place where it contacts the joint of the hat-shaped steel sheet pile. Features.

  In the present invention, instead of the hat-shaped steel sheet pile, it is also possible to use a Z-shaped steel sheet pile in which two cross-sectional shapes are fitted in advance. Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a composite wall structure using a plurality of hat-shaped steel sheet piles connected as steel retaining walls according to an embodiment of the present invention. FIG. 2 shows an underground structure having the composite wall structure shown in FIG. A vertical sectional view of an object (basement with a drainage pit) is shown.

  In these figures, 1 is a steel retaining wall, 2 is a hat-shaped steel sheet pile, 3 is a joint of a hat-shaped steel sheet pile, 4 is a stud with a head, 5 is a back-reinforced concrete wall, 6 is a drainage groove, 7 is Reinforcing bars, 8 is a gap, 9 is a waterproof layer, 10 is a floorboard, 20 is a drainage pit, 21 is a flange of a hat-shaped steel sheet pile, and 22 is a basement.

  The steel earth retaining wall 1 is configured by connecting a plurality of hat-shaped steel sheet piles 2 so that the joint portion 3 does not come into contact with the post-worked reinforced concrete wall 5. Below the steel earth retaining wall 1, a waterproof layer 9 is laid so as to be in contact with the inside thereof, and a post-reinforced concrete wall 5 and a floor board 10 of an underground structure are constructed thereon.

  The reinforced concrete wall 5 is constructed by placing concrete in a substantially straight line over the flange 21 of the hat-shaped steel sheet pile 2, and headed studs 4 are attached to the flange 21 at a predetermined interval. Reinforced concrete wall 5 is integrated. Reinforcing bars 7 are laid in the reinforced concrete wall 5 in the horizontal and vertical directions with the wall surface of the steel earth retaining wall 1.

  A perforated steel plate gibber may be used instead of the headed stud 4. The headed stud 4 is welded after the steel sheet pile is cast and then excavated in the retaining ring. However, in the case of a perforated steel plate gibber, it may be welded to the steel sheet pile before placing depending on the ground conditions. .

  The joint portion 3 of the hat-shaped steel sheet pile 2 is located on a convex portion with respect to the reinforced concrete wall so as not to contact the reinforced concrete wall 5 and is surrounded by the joint portion 3 of the hat-shaped steel sheet pile 2, the reinforced concrete wall 5 and the waterproof layer 9. A region having a substantially trapezoidal cross section is a cavity 8. A drainage groove 6 is provided in the waterproof layer 9 which is the lower end of the cavity 8.

  Change in fitting state of the joint portion 3 by adopting a structure in which the joint portion 3 and the reinforced concrete wall 5 are not in direct contact with each other, and a region surrounded by the hat-shaped steel sheet pile 2 and the reinforced concrete wall 5 is a cavity 8. Accordingly, it is possible to suppress the occurrence of cracks in the post-cast reinforced concrete wall 5.

  Moreover, even if water leaks from the joint portion 3 of the hat-shaped steel sheet pile 2, the water that has flowed into the cavity is quickly drained by the drainage groove 6 provided at the lower end portion of the cavity 8. Water pressure does not act. Further, the leachate and the dew condensation water are collected at one place through the drainage groove 6 and discharged to the outside of the drainage pit 20 by a pump.

  Although the leachate from the joint 3 is discharged by the drainage groove 6, the joint 3 is preferably water-stopped, and a water-stopping material such as urethane resin is mainly used before the hat-shaped steel sheet pile 2 is placed. It is preferable to apply a coating-type water-swellable water stop material as a component. Since it is possible to stop water even when used as a soil retaining, workability is improved.

  When the composite wall according to the present invention is used for the side wall of the basement 22, the cavity 8 becomes a heat insulating layer, and condensation in the basement wall 22 is suppressed, and moisture condensed in the cavity 8 is drained from the lower end portion. The inside of the wall 22 is not adversely affected.

  In the synthetic wall structure according to the present invention, the possibility of the penetration of groundwater or the like is limited to the joint of the hat-shaped steel sheet pile wall, so the range of collecting water is very limited.

  In the case of the method of draining groundwater by placing drainage material in the vicinity of the steel core material that has been implemented conventionally, the drainage material has the property that the surface does not harden concrete but cannot penetrate inside, but water can pass through An expensive one was necessary.

  In the synthetic wall structure according to the present invention, drainage is not required and it is sufficient to use a simple cavity, so that it is economical and the possibility of clogging is low. Furthermore, when improving heat insulation, since the amount of water leakage from the joint subjected to the water stop treatment is very small, the inside of the cavity 8 may be filled with a material such as glass wool having water permeability and heat insulation.

FIG. 3 shows an example in which the composite wall according to the present invention is applied to the side wall of a one-layer two-span box-type cross section tunnel.
The passage 23 of the 1-layer 2-span box-shaped tunnel has a steel retaining wall 1 and a post-cast reinforced concrete wall 5 integrated with a headed stud 4 to form a synthetic wall as an underground wall, and a floor plate 10 is provided above the drainage layer 9. It is constructed in a space surrounded by the top plate 11.

  In FIG. 4, instead of the hat-shaped steel sheet pile, a steel retaining wall 1 is constructed by using a Z-shaped steel sheet pile 12 in which two cross-sectional shapes are fitted in advance, and the steel sheet retaining wall 1 is made. The horizontal sectional view of the synthetic wall which filled the space | gap formed between the wall 1 and the reinforced concrete wall 5 with the glass wool 14 is shown.

  The Z-shaped steel sheet pile 12 is previously fitted in a set of two sheets, and a welded portion 13 is placed. In addition, as for Z-shaped steel sheet pile 12, it is standardly carried out to make a set of two sheets as a countermeasure against twisting at the time of placing. The fitting portion 13 may be welded or mechanically caulked with a press after applying a water-stopping material.

  The shape of the Z-shaped steel sheet pile 12 fitted in a set of two sheets is almost similar to that of the hat-shaped steel sheet pile, and the joint is made so that the wall surface 21a including the fitting portion 13 becomes a planned contact surface with the reinforced concrete wall 5. Connected by part 3 and placed.

  The reinforced concrete wall 5 is constructed by placing concrete in a substantially straight line over the wall surface 21 a including the fitting portion 13, and the headed studs 4 are attached to the wall surface 21 a at a predetermined interval. Reinforced concrete wall 5 is integrated.

  The stopper is generally a headed stud 4, but a perforated steel plate gibel may be used. The headed stud 4 is welded after excavating the retaining ring after the Z-shaped steel sheet pile 12 is placed. In the case of a perforated steel plate gibber, it is welded to the Z-shaped steel sheet pile 12 before placing depending on the ground conditions. It is also possible to keep it.

  Moreover, it is also possible to perform the water stop process of the joint part from the inside of the earth retaining member after the inside of the earth retaining wall is excavated and before the post-cast concrete is placed.

  In the reinforced concrete wall 5, the reinforcing bars 7 are arranged in the horizontal and vertical directions with the wall surface 21 a of the steel earth retaining wall 1. Glass wool 14 is filled in a substantially trapezoidal gap formed between the steel earth retaining wall 1 and the reinforced concrete wall 5.

  When constructing the above-mentioned composite wall, after placing concrete, in order to secure a substantially trapezoidal cavity between the steel retaining wall 1 and the reinforced concrete wall 5, the cavity 8 is made of plywood before placing the concrete. However, the space is narrow and it is difficult to release the plywood formwork after the concrete is hardened.

  Therefore, in the present invention, when improving workability and economic efficiency, after placing the concrete so as not to use the plywood formwork, the foamed polystyrene type is used instead of the plywood formwork in the pre-low region where the cavity 8 is formed. Arrange the frame.

  FIG. 6 is a schematic view showing an example of a polystyrene foam form, in which (a) is a plan view and (b) is a side view. The styrofoam formwork 15 has a notch portion 16 including these joint portions at a location where it comes into contact with a joint portion of a hat-shaped steel sheet pile or a Z-shaped steel sheet pile in which two sheets are previously fitted. The notch portion 16 also functions as a drainage path for water leaking from the joint portion.

  The illustrated polystyrene foam form 15 has an integral structure, but may be divided into sizes that can be transported and stacked on site.

  FIG. 7 shows the formation between the steel retaining wall 1 and the reinforced concrete wall 5 by the foamed mold 15 divided into a size that can be transported before placing the concrete over the flange 21 of the hat-shaped steel sheet pile 2. The state which is filled with the area | region used as the cavity to be performed is shown, and the state fixed to the waterproof layer 9 is shown, (a) is a top view, (b) shows a side view.

The polystyrene foam mold 15 is inserted in the notch 16 in the vertical direction, the lower end is fixed to the waterproof layer 9 serving as the bottom surface of the cavity, and the end plate 18 is in contact with the upper surface of the foam polystyrene mold 15 at the upper end. It is fixed to the waterproof layer 9 which becomes the bottom surface of the cavity by a wire rope 19 having
The wire rope 19 is connected to the end plate 18 by a fixture 17.

  FIG. 5 shows a horizontal sectional view of a composite wall in which concrete is cast over the flange 21 of the hat-shaped steel sheet pile 2 of the steel retaining wall 1 shown in FIG. 7 to construct a reinforced concrete wall 5.

  FIG. 8 shows an example of an underground structure provided with a synthetic wall using a polystyrene foam frame 15, (a) is a plan view of the wall surface of the underground structure, and (b) is one of the underground structure. The side view of a part is shown. The groundwater leaked from the joint 3 of the hat-shaped steel sheet pile 2 is guided to the lower part by gravity through the notch 16 of the polystyrene foam form 15.

  The water leakage passes through the reinforced concrete wall 5 and the hat-shaped steel sheet pile 2 so as to connect the drainage groove 6 and the water collection pit 20 and is discharged to the water collection pit 20. After collecting the water leakage from the underground outer wall in the water collecting pit 20 installed in the deepest part, it is drained by a pump. In this figure, the same reference numerals as those in FIG. 7 denote the same elements. The polystyrene foam mold 15 functions not only as a mold but also as a heat insulating material, and alleviates condensation in the basement 22. In this figure, the same reference numerals as those in FIG.

  The construction method of the synthetic wall structure concerning this invention is demonstrated using FIG. First, the hat-shaped steel sheet pile 2 is placed, and the soil on the front is excavated. After cleaning the earth and sand adhering to the hat-shaped steel sheet pile 2, the stud 4 is welded.

  Next, the polystyrene foam frame 15 divided into lengths that can be transported and constructed is stacked from below. A wire rope 19 having end plates 18 at both ends is passed through the notch, and tension is applied to fix the polystyrene foam frames 15 together.

  In the case where the bottom plate portion is concrete, an anchor is buried and the lower end of the wire rope 19 is fixed. The lowermost polystyrene foam form 15 is provided with a drainage hole so that water collected through the drainage channel can be discharged. This is not the case when a drainage channel is provided in the bottom plate portion under the lowermost foamed mold 15.

  The material of the mold is not limited to polystyrene foam, but may be a material that has the strength to withstand the pressure of concrete that does not harden, the durability to withstand long-term use, and the heat insulation. However, a light one is desirable from the viewpoint of workability, and economical efficiency is also required.

  Since the polystyrene foam form 15 is lightweight and can be easily operated by human power, it can be constructed safely and quickly compared to the conventional form work using plywood.

The horizontal sectional view explaining the synthetic wall structure concerning one example of the present invention. The vertical sectional view of the underground structure (drainage pit) which has the synthetic wall structure shown in FIG. The vertical sectional view of the 1 layer 2 span box type cross section tunnel to which the synthetic wall concerning the present invention is applied. A cross-sectional shape according to another embodiment of the present invention is a hat shape, and a clay retaining wall is constructed with Z-shaped steel sheet pile steel in which two pieces are fitted in advance, and the steel retaining wall and the reinforced concrete wall are The horizontal sectional view of the synthetic wall which filled the space | gap formed in between with glass wool. The horizontal sectional view of the synthetic | combination wall using the polystyrene foam form which concerns on other one Example of this invention. It is a figure explaining a foamed polystyrene formwork, (a) is a top view, (b) is a front view. It is a figure explaining the fixing method of the divided | segmented polystyrene foam formwork in the synthetic | combination wall using the polystyrene foam form which concerns on other one Example of this invention, (a) is a top view, (b) is a front view. An example of the underground structure provided with the synthetic wall using the polystyrene foam formwork is shown, (a) is a plan view of the wall surface of the underground structure, and (b) is a side view of a part of the underground structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steel earth retaining wall 2 Hat-shaped steel sheet pile 3 Joint part 4 Head stud 5 Post-stressed concrete wall 6 Drainage groove 7 Reinforcement 8 Cavity 9 Waterproof layer 10 Floor board 11 Top board 12 Z-shaped steel sheet pile 13 Fitting part 14 Glass wool 15 Styrofoam Formwork 16 Notch 17 Fixing 18 End plate 19 Wire rope 20 Drain pit 21 Flange 22 Basement 23 Passage

Claims (14)

A composite wall structure in which a steel earth retaining wall and a post-cast reinforced concrete wall are integrated with a stud provided on a contact surface of the steel earth retaining wall with the post-cast reinforced concrete wall,
The steel earth retaining wall is configured by connecting a hat-shaped steel sheet pile or a Z-shaped steel sheet pile fitted with two pieces so as to form a hat-shaped cross section in advance,
When the steel sheet pile of the steel retaining wall is a hat-type steel sheet pile, the post-cast reinforced concrete wall is placed with concrete in a straight line over the flange portion and fitted with two pieces so as to make a hat-shaped cross section in advance. In the case of the combined Z-shaped steel sheet pile, it is constructed by placing concrete substantially linearly over the wall surface including the fitting part,
A region surrounded by the steel retaining wall and the post-cast reinforced concrete wall is a cavity, and a discharge path for discharging leaked groundwater to the outside of the post-cast reinforced concrete wall is provided at the bottom of the cavity. Synthetic wall structure. The hat-shaped steel sheet pile for constructing a steel retaining wall or a joint portion of a Z-shaped steel sheet pile fitted with two pieces so as to form a hat-shaped cross section is water-stopped. Composite wall structure. The inside of the cavity is a hat-shaped steel sheet pile, or Z that has been fitted in advance to form a hat-shaped cross section.
The composite wall structure according to claim 1 or 2, wherein the composite wall structure is filled with a polystyrene foam frame including a joint portion of a shaped steel sheet pile and having a cutout portion which is connected to a discharge path provided in a bottom surface of the cavity. .   The synthetic wall structure according to claim 3, wherein the polystyrene foam form is divided into a plurality in the height direction. The foamed polystyrene frame is inserted into the cutout portion in the vertical direction, the lower end is fixed to the bottom surface of the cavity, and the upper end is a wire rope having an end plate in contact with the upper surface of the expanded polystyrene frame, The composite wall structure according to claim 3 or 4, wherein the composite wall structure is fixed to a bottom surface of the cavity.   After building a steel retaining wall by placing a hat-shaped steel sheet pile or a Z-shaped steel sheet pile with two joints fitted in advance so as to form a hat-shaped cross section, excavating the soil on the front, A stud is welded to the planned contact surface of the earth retaining wall with the post-cast reinforced concrete wall, and a discharge path is formed on the bottom surface of the planned cavity between the steel earth retaining wall and the post-cast concrete wall, and then the drain path is A composite wall construction method comprising constructing a post-cast reinforced concrete wall by placing concrete in a substantially straight line along the planned contact surface so as not to be buried. 7. A post-cast reinforced concrete wall is constructed by placing a foamed polystyrene formwork in the cavity cavity after forming a discharge path on the bottom surface of the cavity cavity, and then placing concrete. To construct a composite wall. The method for constructing a synthetic wall according to claim 7, wherein the foamed polystyrene frame has a notch that includes a joint of a hat-shaped steel sheet pile or a Z-shaped steel sheet pile.   9. The method for constructing a synthetic wall according to claim 8, wherein the polystyrene foam form is divided into a plurality in the height direction. The said polystyrene foam formwork is fixed and arrange | positioned at the bottom face of the said cavity with the wire rope which has an end plate which contacts the upper surface of the said polystyrene foam formwork formwork in an upper end part. How to construct a synthetic wall. The composite wall according to any one of claims 1 to 5 is used as a wall surface, and has a waterproof layer connected to a steel retaining wall below the composite reinforced concrete wall of the composite wall, A drainage structure is provided in which a discharge path for discharging groundwater leaking into a cavity between the post-cast reinforced concrete wall and the steel earth retaining wall is provided.   The steel earth retaining wall is constructed with a hat-shaped steel sheet pile or a Z-shaped steel sheet pile fitted in advance with a joint so as to make a hat-shaped cross section, and at the joint part so as to make a hat-shaped steel sheet pile or a hat-shaped cross section in advance. The underground structure according to claim 11, further comprising: a foamed polystyrene mold frame having a notch portion including a joint portion of a fitted Z-shaped steel sheet pile in the cavity.   The underground structure according to claim 12, wherein the polystyrene foam form is divided into a plurality in the height direction. The foamed polystyrene frame is inserted in the cutout portion in the vertical direction, the lower end is fixed to the bottom surface of the cavity, and the upper end is a wire rope having an end plate in contact with the upper surface of the expanded polystyrene frame, 2. The bottom surface of the cavity is fixed.
The underground structure according to 2 or 13.

Images