CN113431031A

CN113431031A - Prestress assembly type underground continuous wall and construction method thereof

Info

Publication number: CN113431031A
Application number: CN202110927977.8A
Authority: CN
Inventors: 魏良甲; 刘长帅; 芮斯瑜; 孙峻岭
Original assignee: Hanyang International Engineering Consulting Co Ltd
Current assignee: Hanyang International Engineering Consulting Co Ltd
Priority date: 2021-08-13
Filing date: 2021-08-13
Publication date: 2021-09-24

Abstract

The invention discloses a prestress assembly type underground continuous wall, which comprises a unit wall I and a unit wall II which are alternately connected to enclose and form a ring structure or a polygonal structure, wherein the adjacent ends of the unit wall I and the unit wall II are matched with each other to form a closed cavity, the unit wall I and the unit wall II are connected and fixed by pouring concrete in the closed cavity, the unit wall I and the unit wall II adopt a box structure with a cavity, a steel reinforcement cage structure is embedded in the box structure, the steel reinforcement cage structure comprises steel reinforcements I which are transversely arranged at the transverse part of the box structure, steel reinforcements II which are vertically arranged at the transverse part and the longitudinal part of the box structure, tie reinforcements for hooping part of the steel reinforcements II in the transverse part and hoop reinforcements I for hooping the steel reinforcements II at the corresponding positions of the vertical part, and through the arrangement, the underground continuous wall is good in waterproof performance, simple to construct and reliable in connection.

Description

Prestress assembly type underground continuous wall and construction method thereof

Technical Field

The invention relates to an assembled diaphragm wall structure, in particular to a prestressed assembled underground diaphragm wall and a construction method thereof.

Background

The foundation pit support structure in the water-rich area mainly adopts an underground continuous wall, generally adopts a cast-in-place structure, and the joint form of the groove section of the underground wall is mostly an I-shaped steel joint. The cast-in-place underground diaphragm wall needs to construct guide walls along two sides of the axis of the underground wall before the excavation of the underground diaphragm wall groove section, then excavate the underground diaphragm wall groove section, after the excavation is finished, the reinforcement cage needs to be bound on site, then the reinforcement cage is hoisted into the underground diaphragm wall groove section through hoisting equipment, and finally concrete is used for pouring to form the underground foundation pit enclosure structure, but the cast-in-place structure of the underground diaphragm wall has the following defects:

1. the field is required to be large for binding the reinforcement cage on site; when the reinforcement cage is hoisted, more equipment is required;

2. the hoisting clearance is large, and the construction risk is high;

3. in addition, concrete needs to be poured underwater and cannot be vibrated, the quality of a wall body is difficult to guarantee, and water leakage is easy to occur in a joint.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a design and construction method of an underground diaphragm wall, which has the advantages of concrete pouring quality meeting the use requirement, good waterproof performance, simple construction and reliable connection.

The technical purpose of the invention is realized by the following technical scheme: the utility model provides a prestressing force assembled underground continuous wall, includes that it is continuous in turn in order to enclose and covers unit wall I and unit wall II that form loop configuration or polygon structure, the butt of unit wall I and unit wall II pairs each other and forms the closed chamber, through pour concrete in the closed chamber in order to connect fixedly unit wall I and unit wall II, unit wall I and unit wall II adopt the box structure that is equipped with the cavity in, the box structure is buried and is had the steel reinforcement cage structure, the steel reinforcement cage structure including transverse arrangement in the reinforcing bar I of transverse part of box structure, vertical arrangement in the reinforcing bar II of transverse part and the longitudinal part of box structure, the lacing wire that is used for cramping part reinforcing bar II in the transverse part and the hoop wire I that is used for cramping the reinforcing bar II that the vertical part corresponds the position.

Further, unit wall I is including concatenation upper segment unit wall I and hypomere unit wall I as an organic whole, unit wall II is including concatenation upper segment unit wall II as an organic whole and hypomere unit wall II, the seam crossing of upper segment unit wall I and hypomere unit wall I and the seam crossing of upper segment unit wall II and hypomere unit wall II stagger the setting.

Furthermore, the joints of the upper section unit wall I and the lower section unit wall I and the joints of the upper section unit wall II and the lower section unit wall II are both in a tenon-and-mortise structure, and epoxy resin sealant is coated at the joints of the tenon-and-mortise structure.

Furthermore, a preformed hole I for installing a steel bundle of a tensioning prestress and a preformed hole II for installing a common steel bar are respectively arranged in the upper section unit wall I and the lower section unit wall I and in the upper section unit wall II and the lower section unit wall II, and high-strength grouting material is poured in the preformed hole I and the preformed hole II.

Furthermore, horizontal transverse partitions are arranged in the unit wall I and the unit wall II, and stirrups II are arranged in the horizontal transverse partitions.

Further, be located the outside the tip of reinforcing bar I is equipped with the crotch portion of surrounding tip reinforcing bar II, is located the inboard the tip of reinforcing bar I is equipped with the kink that leans out.

A construction method of a prestress assembly type underground continuous wall comprises the following construction steps:

s1, prefabricating a unit wall I and a unit wall II which are embedded with reinforcement cage structures according to a design drawing, wherein the unit wall I and the unit wall II are of upper and lower section structures which are spliced into a whole;

s2, constructing guide walls along two sides of the underground wall axis, excavating mounting grooves at intervals, and cleaning the bottoms of the mounting grooves after the grooves are excavated;

s3, hoisting the lower section unit wall I into the upper part of the mounting groove by using a hoisting device, and fixing the lower section unit wall I by using a temporary support;

s4, hoisting the upper section unit wall I to the upper part of the lower section unit wall I through a hoisting device, longitudinally assembling the upper section unit wall I and the lower section unit wall I, and lowering the integrally assembled unit walls I to a designed elevation through the hoisting device and then fixing the integrally assembled unit walls I through temporary supports;

s5, grouting the mounting groove, wherein the liquid level of the grout is 4-6 m higher than the bottom surface of the unit wall I, and removing the temporary support after the grout at the bottom reaches the designed strength;

s6: carrying out interval construction on the unit wall I, after the unit wall I is constructed, excavating the rest mounting grooves according to the steps S2-S5 and constructing the unit wall II;

s7: after the unit wall I and the unit wall II are constructed, brushing grooves at the joint of the unit wall I and the joint of the unit wall II, pouring underwater concrete for sealing, and performing wet joint at the joint of the unit wall I and the unit wall II;

s8: and (4) pouring a top beam and carrying out foundation pit excavation construction.

Further, the step S4 of longitudinally assembling the upper section unit wall i and the lower section unit wall i includes the following steps:

s-1: coating epoxy resin sealant on the joint of the upper section unit wall I and the lower section unit wall I;

s-2, longitudinally penetrating steel bundles in the upper section unit wall I and the lower section unit wall I, tensioning prestress through the steel bundles and sealing anchors to fasten the upper section unit wall I and the lower section unit wall I;

and S-3, penetrating and arranging common steel bars extending to the lower section unit wall I in the upper section unit wall I.

Further, between step S5 and step S6, grouting is performed into the first preformed hole for accommodating the steel bundle and the second preformed hole for accommodating the ordinary steel bar.

Further, the steps S3 and S4 are replaced by assembling the upper section unit wall I and the lower section unit wall I on the ground, hoisting the assembled unit wall I integrally through a hoisting device, and placing the unit wall I into the installation groove.

In conclusion, the invention has the following beneficial effects:

1. compared with the traditional cast-in-place construction mode, the design improves the concrete pouring quality, reduces the problems of uneven wall surface, limit invasion and the like;

2. the joint is provided with the inserted bars in a reserved mode and concrete is poured later, and compared with the traditional joint form, the overall transverse stress performance and the waterproof performance of the joint are improved;

3. the prefabricated diaphragm wall adopting the design adopts a box-type structure with a cavity, so that the consumption of concrete is greatly reduced, and the material cost is saved;

4. the steel reinforcement cage structure of the prefabricated ground connecting wall does not have vertical and transverse truss ribs and shear ribs of a cast-in-place ground connecting wall steel reinforcement cage, so that the using amount of common steel reinforcements is reduced, and the material cost is saved;

5. the design adopts prefabricated parts, reduces the binding of reinforcing steel bars by field workers, and saves labor cost.

Drawings

Fig. 1 is a schematic view of the overall structure of the fabricated underground diaphragm wall of the present invention.

Fig. 2 is a schematic front and side view of a cell wall i of the present invention.

Fig. 3 is a schematic front and side view of the unit wall ii of the present invention.

FIG. 4 is a schematic view of the structure at the seam of the present invention.

Fig. 5 is a sectional view of the unit wall i and the unit wall ii according to the present invention.

Fig. 6 is a cross-sectional view at a of the present invention.

Fig. 7 is a cross-sectional view at a' of the present invention.

Fig. 8 is a cross-sectional view at B of the present invention.

Fig. 9 is a cross-sectional view at B' of the present invention.

Fig. 10 is a cross-sectional view at C of the present invention.

Fig. 11 is a cross-sectional view at D of the present invention.

Fig. 12 is a cross-sectional view at E of the present invention.

Fig. 13 is a schematic structural diagram of the unit wall I at the lower section of the hoisting device.

Fig. 14 is a schematic structural view of the temporarily fixed lower unit wall i of the present invention.

FIG. 15 is a schematic structural view of the hoisting upper section unit wall I of the present invention.

Fig. 16 is a schematic structural view of the present invention for splicing an upper section unit wall i and a lower section unit wall i.

Fig. 17 is a schematic structural view of the temporarily fixed upper section unit wall i and lower section unit wall i of the present invention.

Figure 18 is a schematic illustration of grouting in an installation slot of the present invention.

Fig. 19 is a schematic structural view of the fixing of the upper section unit wall i and the lower section unit wall i of the present invention.

In the figure: 1. a unit wall I; 11. a groove; 12. a cavity; 13. an upper section of unit wall I; 14. a lower section unit wall I; 15. seaming; 16. reserving a first hole; 161. finish rolling the deformed steel bar anchor head; 17. reserving a second hole; 18. inserting ribs; 19. hoisting holes; 2. a unit wall II; 21. an upper section unit wall II; 22. a lower section unit wall II; 3. a closed cavity; 4. a reinforcement cage structure; 41. reinforcing steel bars I; 411. a hook portion; 412. a bending section; 42. reinforcing steel bars II; 43. stretching a rib; 44. a stirrup I; 5. transverse septa; 51. a stirrup II; 52. a flow guide hole; 6. a guide wall; 61. a temporary support; 7. mounting grooves; 8. a hoisting device; 81. a hoisting ring; 9. a crown beam.

Detailed Description

The invention will be further described with reference to the accompanying drawings.

As shown in fig. 1-12, a prestressed fabricated underground continuous wall comprises a unit wall i 1 and a unit wall ii 2 which are alternately connected to enclose and cover a ring structure or a polygonal structure, wherein adjacent ends of the unit wall i 1 and the unit wall ii 2 are matched with each other to form a closed cavity 3, the unit wall i 1 and the unit wall ii 2 are connected and fixed by pouring concrete in the closed cavity 3, in the invention, grooves 11 which are matched with each other are formed in the unit wall i 1 and the unit wall ii 2, the grooves 11 of the unit wall i 1 are matched with the grooves 11 of the unit wall ii 2 to form the closed cavity 3, more than two groups of insertion ribs 18 are respectively arranged at the end parts of the unit wall i 1 and the unit wall ii 2, one end of each insertion rib 18 is positioned in the unit wall i 1 or the unit wall ii 2, the other end is positioned in the closed cavity 3, and the horizontal rigidity of a joint is enhanced by pouring concrete in the closed cavity 3, in other words, the joint of the present invention is provided with the joint bar 18 and the concrete is post-cast, which improves the overall transverse stress performance and waterproof performance of the joint compared to the conventional joint form, wherein for convenience of description, the invention uses the reference of fig. 6, and the length mode is the transverse part and the width direction is the vertical part.

The prefabricated diaphragm wall of this design adopts the box structure that is equipped with cavity 12 in I1 of unit wall and the adoption of unit wall II 2, and this design is prefabricated even the wall adopts the box structure that is equipped with cavity 12, reduces the quantity of concrete by a wide margin, saves material cost, alleviates ground wall weight, steel reinforcement cage structure 4 has been buried in the box structure, steel reinforcement cage structure 4 includes transversely arranged in steel reinforcement I41 of the horizontal portion of box structure, vertically arranged in the horizontal portion of box structure and the steel reinforcement II 42 of longitudinal portion, be used for cramping the lacing wire 43 of the partial steel reinforcement II 42 in the horizontal portion and be used for cramping the stirrup I44 of the steel reinforcement II 42 of vertical portion corresponding position, and this design adopts prefabricated component, reduces on-the-spot workman's reinforcing bar, saves the cost of labor, compares in traditional cast-in-place construction mode simultaneously, improves concrete placement quality, reduces the wall unevenness and invades limit scheduling problem.

Unit wall I1 is including splicing upper segment unit wall I13 and hypomere unit wall I14 as an organic whole, unit wall II 2 is including splicing upper segment unit wall II 21 and hypomere unit wall II 22 as an organic whole, the setting is staggered in seam 15 department and upper segment unit wall II 21 and hypomere unit wall 15 department of seam 15 department of upper segment unit wall I13 and hypomere unit wall I14, assembles through the stagger joint and makes this underground continuous wall bear the comparatively position of atress stagger in turn, and then increases this underground continuous wall's bulk strength.

The joint 15 of the upper section unit wall I13 and the lower section unit wall I14 and the joint 15 of the upper section unit wall II 21 and the lower section unit wall II 22 are both in a tenon-and-mortise structure, epoxy resin sealant is coated at the joint 15 of the tenon-and-mortise structure, and the shear resistance is improved by adopting the tenon-and-mortise structure.

And a first preformed hole 16 for installing a steel bundle of a tensioning prestress and a second preformed hole 17 for installing a common steel bar are respectively arranged in the upper section unit wall I13 and the lower section unit wall I14 and in the upper section unit wall II 21 and the lower section unit wall II 22, and high-strength grouting material is poured in the first preformed hole 16 and the second preformed hole 17.

The horizontal transverse partitions 5 are arranged in the unit walls I1 and II 2, stirrups II 51 are arranged in the horizontal transverse partitions 5, flow guide holes 52 are formed in the horizontal transverse partitions 5, and the unit walls I1 and II 2 can smoothly sink into the mortar through the arrangement of the flow guide holes 52.

The horizontal part of unit wall I1 and unit wall II 2 does not be equipped with two sets of intervals the reinforcing bar I41 that sets up, and vertical portion is equipped with the reinforcing bar II 42 that the multiunit was arranged and is set up, wherein is located the outside the tip of reinforcing bar I41 is equipped with the crotch portion 411 that encloses and cover tip reinforcing bar II 42, is located the inboard the tip of reinforcing bar I41 is equipped with the kink 412 that leans out, and this structure setting strengthens the tip intensity of this unit wall I1 and unit wall II 2.

As shown in fig. 13 to 19, the construction method of the prestressed fabricated underground diaphragm wall includes the following construction steps:

s1, prefabricating a unit wall I1 and a unit wall II 2 which are embedded with a reinforcement cage structure 4 according to a design drawing, wherein the unit wall I1 and the unit wall II 2 are of an upper section structure and a lower section structure which are spliced into a whole;

s2, constructing guide walls 6 along two sides of the underground wall axis to prevent collapse of surface soil and ensure grooving precision, excavating the mounting groove 7 at intervals, filling slurry into the mounting groove 7 all the time in the process of excavating the mounting groove 7 to keep the groove wall stable, and cleaning the bottom of the mounting groove 7 after grooving is finished;

s3, hoisting the lower section unit wall I14 into the upper part of the mounting groove 7 through the hoisting device 8, fixing the lower section unit wall I14 by adopting the temporary support 61, and removing the hoisting ring 81 of the hoisting device 8 after the fixing is finished;

s4, hoisting the upper section unit wall I13 to the upper part of the lower section unit wall I14 through the hoisting device 8, longitudinally assembling the upper section unit wall I13 and the lower section unit wall I14, lowering the integrally assembled unit walls I1 to a designed elevation through the hoisting device 8, fixing the integrally assembled unit walls I1 through the temporary support 61, and removing the hoisting rings 81 of the hoisting device 8 after the fixation is finished;

s5, grouting the installation groove 7, wherein the liquid level of the grout is 4-6 m higher than the bottom surface of the unit wall I1 (the best scheme is that the liquid level of the grout is 5m higher than the bottom surface of the unit wall I1), and removing the temporary support 61 after the bottom grout reaches the designed strength;

s6: carrying out interval construction on the unit wall I1, after the unit wall I1 is constructed, excavating the residual mounting grooves 7 according to the steps S2-S5 and constructing the unit wall II 2;

s7: after the unit wall I1 and the unit wall II 2 are constructed, brushing grooves at the joint 15 of the unit wall I1 and the joint 15 of the unit wall II 2, pouring underwater concrete for sealing, and performing wet joint 15 at the joint 15 of the unit wall I1 and the unit wall II 2;

s8: and (5) pouring the top beam 9 and carrying out foundation pit excavation construction.

The steps comprise two stages, wherein a first stage interval type (jumping slot type) excavation is carried out for containing the installation groove 7 of the unit wall I1 and construction is carried out on the unit wall I1, and a second stage interval type (jumping slot type) excavation is carried out for remaining the installation groove 7 used for containing the unit wall II 2 and construction is carried out on the unit wall II 2.

When a site and a hoisting clearance exist on the site, the steps S3 and S4 can be replaced by assembling the upper section unit wall I13 and the lower section unit wall I14 on the ground, integrally hoisting the assembled unit wall I1 through the hoisting device 8, and putting the unit wall I1 into the installation groove 7

The step S4 of vertically assembling the upper section unit wall i 13 and the lower section unit wall i 14 includes the following steps:

s-1: epoxy resin sealant is coated at the joint 15 of the upper section unit wall I13 and the lower section unit wall I14;

s-2, longitudinally penetrating steel bundles in the upper section unit wall I13 and the lower section unit wall I14, and tensioning prestress and sealing anchors through the steel bundles to fasten the upper section unit wall I13 and the lower section unit wall I14;

and S-3, penetrating and arranging common steel bars extending to the lower section unit wall I14 in the upper section unit wall I13.

In the invention, the steel bundle adopts finish-rolled deformed steel bars, and the anchor is sealed through a finish-rolled deformed steel bar anchor head 161.

And between the step S5 and the step S6, a step is added, namely high-strength grouting material is poured into the first preformed hole 16 for containing the steel bundle and the second preformed hole 17 for containing the common steel bar, and the prestress of the steel bundle is unloaded after the strength is reached.

In order to facilitate hoisting of the unit walls I1 and II 2, four opposite-penetrating hoisting holes 19 are formed in the upper section unit wall I13, the lower section unit wall I14, the upper section unit wall II 21 and the lower section unit wall II 22, and the hoisting holes 19 are used for installing a hoisting tool matched with the hoisting rings 81 of the hoisting device 8.

The above description is only a preferred embodiment of the present invention, and all equivalent changes or modifications of the structure, characteristics and principles described in the present invention are included in the scope of the present invention.

Claims

1. The utility model provides a prestressing force assembled underground continuous wall which characterized in that: comprises a unit wall I (1) and a unit wall II (2) which are alternately connected to surround and form a ring structure or a polygonal structure, the adjacent ends of the unit wall I (1) and the unit wall II (2) are matched with each other to form a closed cavity (3), concrete is poured in the closed cavity (3) to connect and fix the unit wall I (1) and the unit wall II (2), the unit wall I (1) and the unit wall II (2) adopt a box-shaped structure with a cavity (12) arranged inside, the steel reinforcement cage structure is characterized in that a steel reinforcement cage structure (4) is embedded in the box-type structure, and the steel reinforcement cage structure (4) comprises steel reinforcements I (41) transversely arranged at the transverse part of the box-type structure, steel reinforcements II (42) vertically arranged at the transverse part and the longitudinal part of the box-type structure, tie bars (43) used for hooping part of the steel reinforcements II (42) in the transverse part, and hoop bars I (44) used for hooping the steel reinforcements II (42) at the positions corresponding to the vertical part.

2. The prestressed fabricated underground diaphragm wall as claimed in claim 1, wherein: unit wall I (1) is including splicing upper segment unit wall I (13) as an organic whole and hypomere unit wall I (14), unit wall II (2) are including splicing upper segment unit wall II (21) as an organic whole and hypomere unit wall II (22), seam (15) department and upper segment unit wall II (21) and the seam (15) department of hypomere unit wall II (22) of seam (15) department of upper segment unit wall I (13) and hypomere unit wall I (14) stagger the setting.

3. A prestressed fabricated underground diaphragm wall as claimed in claim 2, wherein: the joint (15) of the upper section unit wall I (13) and the lower section unit wall I (14) and the joint (15) of the upper section unit wall II (21) and the lower section unit wall II (22) are both in a tenon-and-mortise structure, and epoxy resin sealant is smeared at the joint (15) of the tenon-and-mortise structure.

4. A prestressed fabricated underground diaphragm wall as claimed in claim 2, wherein: and a preformed hole I (16) for installing a steel bundle of a tensioning prestress and a preformed hole II (17) for installing a common steel bar are respectively arranged in the upper section unit wall I (13), the lower section unit wall I (14), the upper section unit wall II (21) and the lower section unit wall II (22), and high-strength grouting material is poured in the preformed hole I (16) and the preformed hole II (17).

5. The prestressed fabricated underground diaphragm wall as claimed in claim 1, wherein: horizontal transverse partitions (5) are arranged in the unit walls I (1) and the unit walls II (2), and stirrups II (51) are arranged in the horizontal transverse partitions (5).

6. The prestressed fabricated underground diaphragm wall as claimed in claim 1, wherein: lie in the outside the tip of reinforcing bar I (41) is equipped with crotch portion (411) of enclosing tip reinforcing bar II (42), lies in the inboard the tip of reinforcing bar I (41) is equipped with kink (412) that leans out.

7. A construction method of a prestress assembly type underground continuous wall is characterized by comprising the following steps: the method comprises the following construction steps:

s1, prefabricating a unit wall I (1) and a unit wall II (2) which are embedded with a reinforcement cage structure (4) according to a design drawing, wherein the unit wall I (1) and the unit wall II (2) are of an upper section structure and a lower section structure which are spliced into a whole;

s2, constructing guide walls (6) along two sides of the axis of the underground wall, excavating the mounting grooves (7) at intervals, and cleaning the bottoms of the mounting grooves (7) after the excavation is finished;

s3, hoisting the lower section unit wall I (14) into the upper part of the mounting groove (7) through the hoisting device (8), and fixing the lower section unit wall I (14) by adopting the temporary support (61);

s4, hoisting the upper section unit wall I (13) to the upper part of the lower section unit wall I (14) through a hoisting device (8), longitudinally assembling the upper section unit wall I (13) and the lower section unit wall I (14), and lowering the integrally assembled unit wall I (1) to a designed elevation through the hoisting device (8) and then fixing the integrally assembled unit wall I (1) through a temporary support (61);

s5, grouting the installation groove (7), wherein the liquid level of grout is 4-6 m higher than the bottom surface of the unit wall I (1), and removing the temporary support (61) after the grout at the bottom reaches the designed strength;

s6: carrying out interval construction on the unit wall I (1), after the unit wall I (1) is constructed, excavating the residual mounting grooves (7) according to the steps S2-S5 and constructing the unit wall II (2);

s7: after the unit wall I (1) and the unit wall II (2) are constructed, grooves are brushed at the joint (15) of the unit wall I (1) and the joint (15) of the unit wall II (2) and underwater concrete is poured for sealing, and wet joints (15) are performed at the joint (15) of the unit wall I (1) and the joint (15) of the unit wall II (2);

s8: and (4) pouring a top beam (9) and carrying out foundation pit excavation construction.

8. The construction method of a prestressed fabricated underground diaphragm wall as claimed in claim 7, wherein: the step S4 of longitudinally assembling the upper section unit wall I (13) and the lower section unit wall I (14) comprises the following steps:

s-1: epoxy resin sealant is coated at the joint (15) of the upper section unit wall I (13) and the lower section unit wall I (14);

s-2, longitudinally penetrating steel bundles in the upper section unit wall I (13) and the lower section unit wall I (14), tensioning prestress through the steel bundles and sealing anchors to fasten the upper section unit wall I (13) and the lower section unit wall I (14);

and S-3, penetrating and arranging common steel bars extending to the lower section unit wall I (14) in the upper section unit wall I (13).

9. The construction method of a prestressed fabricated underground diaphragm wall as claimed in claim 8, wherein: and between the step S5 and the step S6, grouting is carried out in a first preformed hole (16) for accommodating the steel bundle and a second preformed hole (17) for accommodating the common steel bar.

10. The construction method of a prestressed fabricated underground diaphragm wall as claimed in any one of claims 7 to 9, wherein: and S3 and S4 are replaced by assembling the upper section unit wall I (13) and the lower section unit wall I (14) on the ground, integrally hoisting the assembled unit wall I (1) through a hoisting device (8), and placing the unit wall I (1) into the installation groove (7).