WO2021023246A1

WO2021023246A1 - Open foundation pit block construction system and method

Info

Publication number: WO2021023246A1
Application number: PCT/CN2020/107264
Authority: WO
Inventors: 郑礼彬; 凌杰; 姚鑫豪; 顾亮
Original assignee: 上海建工二建集团有限公司
Priority date: 2019-08-07
Filing date: 2020-08-06
Publication date: 2021-02-11
Also published as: CN110409454A

Abstract

The present invention relates to the technical field of foundation pit engineering, and relates to an open foundation pit block construction system and method. The problem in which a partition wall enclosure structure cannot be constructed after an existing foundation pit is excavated, and thereby construction cannot be expedited locally, is targeted. In the present invention, for a foundation pit that has been excavated but cannot be constructed by dividing an enclosure system to achieve partial priority construction for the foundation pit, the foundation pit is divided into a pre-construction region, a support replacement region and a post-construction region; the support replacement region is located between the pre-construction region and the post-construction region; each support in the foundation pit comprises a horizontal support that penetrates the pre-construction region, the support replacement region and the post-construction region, and a longitudinal support intersecting with the horizontal support; a support replacement structure for supporting the support replacement region is provided, so that a support of a corresponding layer of the pre-construction region may first be removed, and an underground structure of the corresponding layer of the pre-construction region may then be constructed, and thereby the priority construction of the partial region of the foundation pit may be implemented without needing the overall construction of the foundation pit to be complete, which thus meets the requirements for special construction periods.

Description

Open foundation pit block construction system and method

Technical field

The invention relates to the technical field of foundation pit engineering, in particular to an open foundation pit block construction system and method.

Background technique

With the development of economy and the improvement of people's living environment requirements, my country's construction and municipal projects have developed rapidly in recent years. In cities, land is scarce, and every inch of land is expensive, so while buildings are developing to the sky, the use of underground space has also become an important direction. The construction of basements, underground shopping malls, and underground garages in high-rise and multi-story buildings will all face foundation engineering and deep foundation pit engineering.

The foundation pit design is based on the principle of "safety, reasonableness, economy, and ease of construction". As the depth of the foundation pit becomes deeper, the complexity of the supporting system and the number of supports increase, and the construction period and construction difficulty also follow.

The deep foundation pit is constructed by the normal construction method. According to the conventional construction, the construction process at the structural stage is generally formed and maintained by the bottom plate construction. After the concrete strength reaches 80% of the design requirement, the previous support can be removed. The first floor structure shall be constructed according to this construction principle until the basement roof is completed. The core idea is that the basement deep foundation pit must be constructed as a whole.

If the deep foundation pit needs to be constructed in blocks, the block enclosure and separation system (such as retaining piles and underground continuous walls for separation) must be completed before excavation, and then the construction of the pit shall be carried out. The principle is that the basement structure of one pit is completed Then excavate adjacent foundation pits.

When the excavation of the foundation pit has been completed and the separation enclosure system has not been set up in advance, the foundation pit must be constructed simultaneously as a whole, and some areas cannot be constructed first.

Summary of the invention

The purpose of the present invention is to provide an open foundation pit block construction system and method, which are safe and reliable. For foundation pits that have been excavated and constructed without a partitioned enclosure system, they can achieve the purpose of pre-construction in some areas of the foundation pit. After the excavation of the foundation pit and the separation enclosure system is not constructed, the existing construction of the part of the foundation pit cannot be performed.

In order to solve the above technical problems, the present invention provides the following technical solutions:

An open block construction system for foundation pits is used for excavated foundation pits. The foundation pit is at least divided into a first construction area, a support replacement area and a post construction area. The foundation pit is provided with several layers of supports from bottom to top, Each support includes a horizontal support that penetrates the first construction area, the support change area, and the later construction area, and a longitudinal support that intersects the transverse support. The support change area is located between the first construction area and the later construction area. A support change structure for supporting the support located in the support change area is provided in the foundation pit.

Preferably, in the above-mentioned open foundation pit block construction system, the support replacement structure includes a first temporary support replacement column, a support replacement board wall, a replacement support rod member, and a second temporary replacement support column. The slab wall is arranged on both sides of the lateral support, one end of the re-supporting slab wall is close to the first construction area, and the other end is close to the post-construction area. The first temporary re-supporting columns are arranged on both sides of the re-supporting slab wall. The upper and lower sides of the transverse support sandwiched between the supporting board walls are respectively provided with an upper edge banding beam and a lower edge banding beam. The two ends of the upper edge banding beam and the lower edge banding beam correspond to The supporting board wall is fixedly connected, the second temporary supporting column is arranged on the bottom plate of the first construction area, and the supporting bar is arranged between the second temporary supporting column and the corresponding first temporary supporting column Pieces.

Preferably, in the above-mentioned open foundation pit block construction system, the bracing structure further includes a third temporary bracing column for supporting the second temporary bracing column, and the third temporary bracing column A strut changing member is arranged between the corresponding second temporary strut changing column.

Preferably, in the above-mentioned open-type foundation pit block construction system, the second temporary bracing column is provided with two bracing rod members for each heightening part, and the bracing rod member located above is connected to the first temporary brace rod member. The same heightening part on the changing support column, the lower changing support rod piece is connected to the last construction part on the first temporary changing support column, and the connection point between the two changing support rod parts and the second temporary changing support column is higher than The elevation before the heightening of the supporting board wall is smaller than that after the heightening of the supporting board wall.

Preferably, in the above-mentioned open foundation pit block construction system, the first temporary support column is fixedly connected with the adjacent longitudinal support.

The invention also discloses a construction method of the open foundation pit block construction system as described above, which includes the following steps:

Step 1: Divide the excavated foundation pit into a first construction area, a support replacement area, and a later construction area. The support replacement area is located between the first construction area and the later construction area. There are several layers of support at the top, and each support includes the horizontal support that penetrates the first construction area, the support replacement area and the later construction area, and the longitudinal support that intersects the horizontal support;

Step two, construct the bottom plate of the support change area and the bottom plate of the first construction area. After the concrete strength of the bottom plate meets the design requirements, construct the support change structure used to support the bottom support of the support change area. The support change structure includes Replacing the slab wall, the first temporary replacing pillar, the upper edge banding beam, the lower edge banding beam, the second temporary replacing pillar with corbels, and the corresponding first and second temporary replacing pillars The bracing rod member between the columns, the bracing wall, the first temporary bracing column, the upper edge banding beam, and the lower edge banding beam are located in the bracing region, and the bracing wall is set on the bottom support On both sides of the lateral support, one end of the support wall is close to the first construction area, and the other end is close to the post-construction area. The first temporary support column is set at both ends of the support wall, and is sandwiched between The upper and lower sides of the transverse support between the support board walls are respectively provided with the upper edge banding beam and the lower edge banding beam, and the two ends of the upper edge banding beam and the lower edge banding beam are respectively corresponding to the support Fixed connection of board and wall;

Step 3: When the concrete strength of the support replacement structure to be used to support the bottom support of the support replacement area reaches the design strength, remove the lowest support of the first construction area;

Step 4: The wall of the support replacement area and the first temporary replacement support columns at both ends are raised to the upper support elevation. The construction is used to support the support replacement structure above the support replacement area and the bottom of the first construction area The floor slab, the support change structure used to support a support above the support change area includes a heightened part on the second temporary support column, the heightened part provided on the second temporary support column and the corresponding first temporary support Change the support rod between the support pillars;

Step 5. The concrete to be used to support the support replacement structure above the support replacement area and the lowermost floor of the first construction area reaches the design strength, and the first construction area is removed and then the upper layer of support is removed;

Step 6, repeat

steps

4 and 5 until the uppermost support of the first construction area is removed, and the roof structure of the first construction area is completed;

Step seven, follow the structure of the construction area after completion;

Step 8. Remove the support structure from top to bottom;

Step Nine, complete the structure of the support replacement area.

Preferably, in the above-mentioned construction method of the open foundation pit block construction system, the second temporary support column is provided with a corbel for arranging the corresponding support rod member.

Preferably, in the construction method of the open foundation pit block construction system, the support replacement structure further includes a third temporary support post for supporting the second temporary support post, and the third temporary support post A strut changing member is arranged between the supporting column and the corresponding second temporary supporting column.

Preferably, in the above-mentioned construction method of the open foundation pit block construction system, the third temporary support column is provided with a corbel for arranging the corresponding support member.

Preferably, in the construction method of the open-type foundation pit block construction system described above, the second temporary support column is provided with two support change rods at each heightened part, and the upper support change rod is connected The same heightened part of the first temporary support column, the lower part of the support replacement rod is connected to the last construction part of the first temporary support column, and the connection of the two support rod parts to the second temporary support column The location is higher than the elevation before the heightening of the supporting board wall and smaller than the elevation after the heightening of the supporting board wall.

From the technical solutions disclosed above, compared with the prior art, the beneficial effects of the present invention are as follows:

The open-type foundation pit block construction system provided by the present invention, for the foundation pits that have been excavated but cannot be divided into the enclosure system through construction to achieve partial priority construction of the foundation pit, by dividing the foundation pit into the first construction area and replacing the support Area and post-construction area, the support replacement area is located between the first construction area and the post-construction area, and each support in the foundation pit includes lateral supports that penetrate the first construction area, the support replacement area and the post-construction area And the longitudinal support that intersects with the horizontal support, by setting up the support change structure for supporting the support change area, the support of the corresponding layer in the first construction area can be removed first, and then the underground structure construction of the corresponding layer in the first construction area can be carried out. Without having to complete the overall construction of the foundation pit, the priority construction of the partial area of the foundation pit can be realized to meet the requirements of special construction period.

The construction method of the open foundation pit block construction system provided by the present invention divides the excavated foundation pit into a first construction area, a support replacement area and a later construction area, and the support replacement area is located between the first construction area and Between the post-construction areas, by sequentially setting up the support replacement structure for supporting the support replacement area, the support of the corresponding layer of the first construction area can be removed first, and then the underground structure of the corresponding layer of the first construction area can be carried out Therefore, it is possible to achieve priority construction in partial areas of the foundation pit without completing the overall construction of the foundation pit to meet the requirements of the special construction period.

Description of the drawings

1 to 25 are schematic diagrams of the construction process of the construction method of the open foundation pit block construction system according to the embodiment of the present invention (also are the structural schematic diagrams of the open foundation pit block construction system at each step).

Fig. 2 is a cross-sectional view of 1-1 in Fig. 1.

Fig. 5 is a cross-sectional view of 2-2 of Fig. 4.

Fig. 8 is a 3-3 sectional view of Fig. 7.

In the picture: 1-bottom plate, 2-transverse support, 3-longitudinal support, 4-first temporary replacement support column, 5-replacement board wall, 6-replacement support member, 7-second temporary replacement support, 8 -Upper edge banding beam, 9-bottom edge banding beam, 10-third temporary replacement support column, 11-main structural column, 12-floor.

detailed description

The present invention will be further described in detail below in conjunction with the drawings and specific embodiments. Hereinafter, the technical content and features of the present invention will be described in detail by the listed embodiments in combination with the accompanying drawings. It should be additionally noted that the drawings are in a very simplified form and all use imprecise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. For the convenience of description, the "up" and "down" described below are consistent with the directions of the upper and lower directions of the drawings, but this cannot be a limitation of the technical solution of the present invention.

Please refer to Figure 1 in conjunction with Figures 2 to 25. This embodiment discloses an open foundation pit block construction system for an already excavated foundation pit. The foundation pit is at least divided into a first construction area and a replacement support There are several layers of supports in the foundation pit from bottom to top. Each support includes a horizontal support 2 that penetrates the first construction area, a support replacement area, and a post construction area, and a longitudinal support 3 that intersects the horizontal support 2. The support change area is located between the first construction area and the post construction area, and a support change structure for supporting the support located in the support change area is provided in the foundation pit.

The open-type foundation pit block construction system provided by the present invention, for the foundation pits that have been excavated but cannot be divided into the enclosure system through construction to achieve partial priority construction of the foundation pit, by dividing the foundation pit into the first construction area and replacing the support Area and post-construction area, the support replacement area is located between the first construction area and the post-construction area, and each support in the foundation pit includes lateral supports that penetrate the first construction area, the support replacement area and the post-construction area 2 and the longitudinal support 3 that intersects with the lateral support 2. By setting the support replacement structure for supporting the support replacement area, the support of the corresponding layer in the first construction area can be removed first, and then the underground structure of the corresponding layer in the first construction area can be removed Therefore, it is possible to achieve priority construction in partial areas of the foundation pit without completing the overall construction of the foundation pit to meet the requirements of the special construction period.

Preferably, in the above-mentioned open foundation pit block construction system, the support replacement structure includes a first temporary support replacement column 4, a support replacement board wall 5, a support replacement member 6 and a second temporary replacement support column 7. The supporting board wall 5 is arranged on both sides of the lateral support 2, one end of the supporting board wall 5 is close to the first construction area, the other end is close to the post construction area, and the first temporary supporting column 4 is arranged at At both ends of the supporting board wall 5, the upper and lower sides of the lateral support 2 sandwiched between the supporting board wall 5 are respectively provided with an upper edge banding beam 8 and a lower edge banding beam 9, the upper sealing The two ends of the edge beam 8 and the lower edge banding beam 9 are respectively fixedly connected to the corresponding support plate wall 5, the second temporary support column 7 is arranged on the bottom plate 1 of the first construction area, and the second temporary A strut changing member 6 is provided between the supporting pole 7 and the corresponding first temporary supporting pole 4. By arranging the support wall 5 on both sides of the lateral support 2, the upper and lower sides of the lateral support 2 sandwiched between the support wall 5 are provided with an upper edge banding beam 8 and a lower edge banding beam 9, respectively, The two ends of the upper edge banding beam 8 and the lower edge banding beam 9 are respectively fixedly connected to the corresponding support plate wall 5, which can realize the support of the lateral support 2. The provision of the first temporary support column 4 can strengthen the strength of the support plate wall 5; by arranging a second temporary support column 7 on the bottom plate 1 of the first construction area, the second temporary support column 7 The bracing rod member 6 is arranged between the corresponding first temporary bracing column 4, which can further improve the supporting effect of the bracing plate wall 5 on the lateral support 2 and realize the safe and reliable construction of the foundation pit.

Preferably, in the above-mentioned open foundation pit block construction system, the support replacement structure further includes a third temporary support post 10 for supporting the second temporary support post 7, and the third temporary support post A strut changing member 6 is arranged between the strut 10 and the corresponding second temporary strut changing 7. When the second temporary support post 7 is increased and the stability becomes weaker, a third temporary support post 10 can be added, and the third temporary support post 10 and the corresponding second temporary support post 10 can be added. The supporting rod member 6 is arranged between 7 to improve the stability of the second temporary supporting column 7, thereby ensuring the stability of the supporting structure and ensuring construction safety.

Preferably, in the above-mentioned open-type foundation pit block construction system, the second temporary bracing column 7 is provided with two bracing rod members 6 each time the height is increased, and the bracing rod member 6 located above is connected The same heightened part on the first temporary support column 4, the lower support rod member 6 is connected to the last construction part of the first temporary support column 4, and the two support rod members 6 are connected to the second temporary The joint of the brace 7 is higher than the elevation of the support wall 5 before heightening and less than the elevation of the brace wall 5 after heightening, so that it is between the first temporary replacement support column 4 and the second temporary replacement support column 7 A broken-line support structure is formed to provide strong support to the first temporary support column 4, and further to achieve stable support for the support located in the support change area.

Preferably, in the above-mentioned open foundation pit block construction system, the third temporary bracing column 10 is provided with a corbel (not shown) for arranging the corresponding bracing rod member 6. By arranging the corbel, it is not only convenient to install the strut changing member 6, but also the stability of the strut changing member 6 can be improved.

Preferably, in the above-mentioned open foundation pit block construction system, the first temporary support column 4 is fixedly connected to the adjacent longitudinal support 3, so that the longitudinal support 3 of the foundation pit can be used for the first temporary support The supporting function of the column 4 improves the stability of the first temporary support replacement column 4, thereby further improving the stability of the support replacement structure.

Please continue to refer to FIGS. 1-25. The present invention also discloses a construction method of the open foundation pit block construction system as described above, which includes the following steps:

Step 1: Divide the excavated foundation pit into a first construction area, a support replacement area, and a later construction area. The support replacement area is located between the first construction area and the later construction area. There are several layers of supports at the top, and each support includes a horizontal support 2 that penetrates the first construction area, a support replacement area, and a later construction area, and a longitudinal support 3 that intersects the horizontal support 2;

Step two, please refer to Figure 1 to Figure 2. Construction of the bottom plate 1 of the support replacement area and the bottom plate 1 of the first construction area. After the concrete strength of the bottom plate 1 reaches the design requirements, construct the bottom support for the support replacement area Support replacement structure, the support replacement structure includes the support replacement wall 5, the first temporary replacement support column 4, the upper edge sealing beam 8, the lower edge sealing beam 9, and the second temporary replacement support column 7 with a corbel And the supporting rod member 6 arranged between the corresponding first temporary supporting column 4 and the second temporary supporting column 7, the supporting plate wall 5, the first temporary supporting column 4, the upper edge banding beam 8, The lower edge banding beam 9 is located in the support replacement area, the support replacement wall 5 is arranged on both sides of the lowermost supported transverse support 2, one end of the support replacement wall 5 is close to the first construction area, and the other end is close to the rear In the construction area, the first temporary bracing column 4 is arranged at both ends of the bracing wall 5, and the upper and lower sides of the lateral support 2 sandwiched between the bracing wall 5 are respectively provided Upper edge banding beam 8 and lower edge banding beam 9, both ends of said upper edge banding beam 8 and lower edge banding beam 9 are respectively fixedly connected to the corresponding supporting board wall 5;

Step 3. Refer to Figure 3. When the concrete strength of the support replacement structure to be used to support the bottom support of the support replacement area reaches the design strength, remove the lowest support of the first construction area;

Step 4, please refer to Figure 4 to Figure 5. The support wall 5 and the first temporary support column 4 at both ends in the support change area are raised to the upper support elevation, and the construction is used to support the change of a support above the support change area. The support structure and the lowermost floor 12 of the first construction area, the support replacement structure used to support a support above the support replacement area includes a heightened part on the second temporary support replacement column 7, which is arranged in the second temporary support replacement The heightened part of the column 7 and the corresponding first temporary change support rod member 6 between the support column 4;

Step 5, please refer to Figure 6. The concrete to be used to support the support replacement structure above the support replacement area and the lowermost floor 12 of the first construction area reaches the design strength, and the first construction area is removed and then the upper layer of support is removed;

Step 6, refer to Figure 7 to Figure 10, repeat steps 4 and 5 until the top support of the first construction area is removed, and the roof structure of the first construction area is completed;

Step 7, refer to Figure 11 to Figure 16, and follow the structure of the construction area after completion;

Step 8. Please refer to Figure 17 to Figure 19 to remove the support structure from top to bottom;

Step 9: Please refer to Figure 20 to Figure 25 to complete the structure of the support replacement area.

Preferably, in the construction method of the open foundation pit block construction system described above, the support replacement structure further includes a third temporary support post 10 for supporting the second temporary support post 7, and the second temporary support post 7 The third temporary support change post 10 and the corresponding second temporary support change post 7 are provided with a support change member 6. When the second temporary support post 7 is increased and the stability becomes weaker, a third temporary support post 10 can be added, and the third temporary support post 10 and the corresponding second temporary support post 10 can be added. The supporting rod member 6 is arranged between 7 to improve the stability of the second temporary supporting column 7, thereby ensuring the stability of the supporting structure and ensuring construction safety.

Preferably, in the construction method of the open foundation pit block-by-block construction system, the third temporary support column 10 is provided with a corbel for arranging the corresponding support rod member 6. The second temporary support pole 7 is provided with a corbel for arranging the corresponding support pole member 6. By arranging the corbel, it is not only convenient to install the strut changing member 6, but also the stability of the strut changing member 6 can be improved.

Preferably, in the construction method of the open foundation pit block construction system described above, the second temporary support column 7 is provided with two support rod members 6 each time the height is increased, and the upper support rod Piece 6 is connected to the same heightened part of the first temporary support column 4, and the lower part of the support replacement member 6 is connected to the last construction part of the first temporary change of support column 4. The two replacement support members 6 and the second 2. The junction of the temporary support column 7 is higher than the elevation of the support replacement wall 5 before heightening and less than the elevation of the support replacement wall 5 after the heightening, so that the first temporary support column 4 is replaced with the second temporary support column A broken-line support structure is formed between 7 to provide strong support for the first temporary support column 4, and further to achieve stable support for the support located in the support change area.

The foregoing description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention in any way. Any changes or modifications made by persons of ordinary skill in the field of the present invention based on the foregoing disclosure shall fall within the protection scope of the claims.

Claims

An open foundation pit block construction system, characterized in that it is used for an excavated foundation pit. The foundation pit is at least divided into a first construction area, a support replacement area and a post-construction area. The foundation pit is provided with Several layers of support, each support includes a horizontal support that penetrates the first construction area, the support change area, and the post construction area, and a longitudinal support that intersects the transverse support, the support change area is located between the first construction area and the post construction area In between, the foundation pit is provided with a support changing structure for supporting the support located in the support changing area.
The open-type foundation pit block construction system according to claim 1, wherein the support replacement structure includes a first temporary support replacement column, a support replacement board wall, a support replacement member, and a second temporary replacement support column, The supporting board wall is arranged on both sides of the lateral support, one end of the supporting board wall is close to the first construction area, and the other end is close to the post construction area, and the first temporary supporting column is arranged on the supporting wall At both ends of the slab wall, the upper and lower sides of the transverse support sandwiched between the supporting slab wall are respectively provided with an upper edge banding beam and a lower edge banding beam, two of the upper edge banding beam and the lower edge banding beam The two ends are respectively fixedly connected to the corresponding supporting wall, the second temporary supporting column is arranged on the bottom plate of the first construction area, and the second temporary supporting column is between the corresponding first temporary supporting column Set up replacement strut pieces.
The open-type foundation pit block construction system according to claim 2, wherein the supporting structure further comprises a third temporary supporting column for supporting the second temporary supporting column, and the third temporary supporting column A bracing rod member is arranged between the temporary bracing column and the corresponding second temporary bracing column.
The open-type foundation pit block construction system according to claim 3, characterized in that, on the part of the second temporary support column that is increased each time, two support rod members are provided, and the upper support rod member Connect the same heightened part on the first temporary re-supporting column, the lower re-supporting rod piece connects the last construction part on the first temporary re-supporting column, the two re-supporting rod parts and the second temporary re-supporting column The joint is higher than the elevation of the wall before and less than the elevation of the wall after the wall is increased.
The open-type foundation pit block construction system according to claim 2, wherein the first temporary support column is fixedly connected with the adjacent longitudinal support.
A construction method of an open foundation pit block construction system according to any one of claims 1-5, characterized in that it comprises the following steps:

Step 1: Divide the excavated foundation pit into a first construction area, a support replacement area, and a later construction area. The support replacement area is located between the first construction area and the later construction area. There are several layers of support at the top, and each support includes the horizontal support that penetrates the first construction area, the support replacement area and the later construction area, and the longitudinal support that intersects the horizontal support;

Step two, construct the bottom plate of the support change area and the bottom plate of the first construction area. After the concrete strength of the bottom plate meets the design requirements, construct the support change structure used to support the bottom support of the support change area. The support change structure includes Replacing the slab wall, the first temporary replacing pillar, the upper edge banding beam, the lower edge banding beam, the second temporary replacing pillar with corbels, and the corresponding first and second temporary replacing pillars The bracing rod member between the columns, the bracing wall, the first temporary bracing column, the upper edge banding beam, and the lower edge banding beam are located in the bracing region, and the bracing wall is set on the bottom support On both sides of the lateral support, one end of the support wall is close to the first construction area, and the other end is close to the post-construction area. The first temporary support column is set at both ends of the support wall, and is sandwiched between The upper and lower sides of the transverse support between the support board walls are respectively provided with the upper edge banding beam and the lower edge banding beam, and the two ends of the upper edge banding beam and the lower edge banding beam are respectively corresponding to the support Fixed connection of board and wall;

Step 3: When the concrete strength of the support replacement structure to be used to support the bottom support of the support replacement area reaches the design strength, remove the lowest support of the first construction area;

Step 4: The wall of the support replacement area and the first temporary replacement support columns at both ends are raised to the upper support elevation. The construction is used to support the support replacement structure above the support replacement area and the bottom of the first construction area The floor slab, the support change structure used to support a support above the support change area includes a heightened part on the second temporary support column, the heightened part provided on the second temporary support column and the corresponding first temporary support Change the support rod between the support pillars;

Step 5. The concrete to be used to support the support replacement structure above the support replacement area and the lowermost floor of the first construction area reaches the design strength, and the first construction area is removed and then the upper layer of support is removed;

Step 6, repeat steps 4 and 5 until the uppermost support of the first construction area is removed, and the roof structure of the first construction area is completed;

Step seven, follow the structure of the construction area after completion;

Step 8. Remove the support structure from top to bottom;

Step Nine, complete the structure of the support replacement area.
7. The construction method of the open foundation pit block construction system according to claim 6, wherein the second temporary support column is provided with a corbel for arranging the corresponding support member.
The construction method of the open-type foundation pit block construction system according to claim 6, wherein the supporting structure further comprises a third temporary supporting column for supporting the second temporary supporting column, so A strut changing member is arranged between the third temporary changing support column and the corresponding second temporary changing support column.
The construction method of the open foundation pit block construction system according to claim 8, wherein the third temporary support column is provided with a corbel for arranging the corresponding support member.
The construction method of the open-type foundation pit block construction system according to claim 6, characterized in that, each heightening part of the second temporary support column is provided with two support rod members, and the upper replacement The struts are connected to the same heightened part on the first temporary replacing column, the lower replacing rod is connected to the last construction part of the first temporary replacing pillar, and the two replacing rods are connected to the second temporary replacing The joints of the supporting columns are higher than the elevation before the heightening of the supporting board wall and smaller than the elevation after the heightening of the supporting board wall.