Construction method for excavation and backbuilding of adjacent foundation pits

Abstract

The invention relates to a construction method for excavation and backbuilding of adjacent foundation pits, and belongs to the technical field of building engineering construction. The construction method comprises seven construction steps. The method is technically characterized in that when one of the two adjacent foundation pits is excavated, the other foundation pit is also excavated in a staggered mode, and compared with the mode that the original foundation pit is excavated after back building, the construction time is greatly shortened. Before the supports are dismantled, the horizontal supporting force close to the foundation pits is increased by arranging the inclined throwing supports, back building and excavation of the foundation pits on the two sides can be conducted at the same time, the construction risk is reduced, and the construction progress of the foundation pits is accelerated.

Description

Technical Field

[0001] The invention relates to a construction method for excavating and backbuilding adjacent foundation pits, belonging to the technical field of building engineering construction. Background Art

[0002] With the continuous development of construction technology and the increasing tension of urban land space, the number and depth of foundation pits in today's construction projects have generally increased. The problems that follow are also obvious, that is, the increase in the safety risk of foundation pits and the construction period. Deep foundation pits often involve pressurized water and complex geological conditions. During the construction of multiple supports, dangerous situations such as deformation of the enclosure, soil disturbance and quicksand, and sudden surge of pressurized water may occur. Although the group foundation pits divide the excavation area and reduce the deformation of the overall foundation pit soil, the foundation pits affect each other during the construction of the foundation pit group, the construction risk is high, and a reasonable excavation sequence is required to ensure that the deformation of each foundation pit is within a controllable and safe range during the excavation process. Even if the excavation sequence is optimized, the construction time is increased compared to single pit excavation. Summary of the invention

[0003] The technical purpose of the present invention is to optimize the construction progress of the group foundation pit and reduce the safety risks during the construction process, so as to solve the problems existing in the prior art such as long construction time and high construction risks.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A construction method for excavating adjacent foundation pits and backfilling includes the following construction steps:

[0006] S1. After the construction of the engineering piles, retaining structures, the middle wall between the two foundation pits, and the first support connecting the retaining structure and the top of the middle wall of the two adjacent foundation pits is completed, the second excavation of the first foundation pit and the second support construction of the first foundation pit are carried out.

[0007] S2. After the second support of the first foundation pit is completed, the third excavation of the first foundation pit and the construction of the bottom plate of the first foundation pit are started, and the second excavation of the second foundation pit and the construction of the second support are carried out at the same time.

[0008] S3. After the bottom plate of the first foundation pit is completed, a first support member is set between the bottom plate and the middle partition wall.

[0009] S4. After the construction of the first support is completed, the second support of the first foundation pit is dismantled and the B1 plate structure is rebuilt. At the same time, the third layer of earthwork of the second foundation pit and the bottom plate of the second foundation pit are excavated.

[0010] S5. After the B1 plate structure of the first foundation pit is rebuilt, the second support member between the B1 plate structure and the middle partition wall is constructed.

[0011] S6. After the construction of the second support is completed, the first support of the first foundation pit is removed, the B0 plate structure is rebuilt, and the second support of the second foundation pit is removed and the B1 plate structure is rebuilt.

[0012] S7. After the above steps are completed, the first support of the second foundation pit, the two support members and the middle partition wall above the second foundation pit bottom plate are dismantled in sequence to complete the B0 plate structure reconstruction of the second foundation pit.

[0013] Furthermore, the first support member in step S3 and the second support member in step S5 are both oblique support members.

[0014] Furthermore, the first support member and the second support member are 609 steel pipes.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. When one of the two adjacent foundation pits is excavated, the other foundation pit is also excavated immediately afterwards. Compared with excavating after the original foundation pit is backfilled, the construction time is greatly shortened.

[0017] 2. Before the support is removed, the horizontal support force of the adjacent foundation pit is increased by setting up inclined support, so that the backfill and excavation of the foundation pits on both sides can be constructed simultaneously, which not only reduces the construction risk but also speeds up the construction progress of the foundation pit. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of construction step S1 in a preferred embodiment of the present invention.

[0019] Figure 2 It is a schematic diagram of construction step S2 in a preferred embodiment of the present invention.

[0020] Figure 3 It is a schematic diagram of construction step S3 in a preferred embodiment of the present invention.

[0021] Figure 4 It is a schematic diagram of construction step S4 in a preferred embodiment of the present invention.

[0022] Figure 5 It is a schematic diagram of construction step S5 in a preferred embodiment of the present invention.

[0023] Figure 6 It is a schematic diagram of construction step S6 in a preferred embodiment of the present invention.

[0024] Figure 7 It is a schematic diagram of construction step S7 in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. According to the following description, the purpose, technical solutions and advantages of the present invention will become clearer. It should be noted that the described embodiments are preferred embodiments of the present invention, rather than all embodiments.

[0026] Combination Figures 1 to 7 As shown, a construction method for excavating adjacent foundation pits and backfilling includes the following construction steps:

[0027] S1. After the construction of the engineering piles 11, the retaining structure 12, the middle partition wall 13 between the two foundation pits and the first support 211 connected to the top of the retaining structure and the middle partition wall of the two adjacent foundation pits is completed, the second skin excavation of the first foundation pit 1 and the second support construction of the first foundation pit 1 are carried out;

[0028] S2. After the second support of the first foundation pit 1 is completed, the third excavation of the first foundation pit 1 and the bottom plate construction of the first foundation pit 1 are started, and the second excavation of the second foundation pit 2 and the construction of the second support 212 are carried out at the same time;

[0029] S3. After the bottom plate of the first foundation pit 1 is completed, a first support member 31 is provided between the bottom plate and the middle partition wall, and the first support member preferably adopts an oblique support;

[0030] S4. After the construction of the first support member 31 is completed, the removal of the second support 212 of the first foundation pit 1 and the B1 plate structure 411 are started, and the third skin earthwork excavation of the second foundation pit 2 and the bottom plate construction of the second foundation pit 2 are carried out;

[0031] S5. After the B1 plate structure 411 of the first foundation pit 1 is back-built, the construction of the second support member 32 between the B1 plate structure 411 and the partition wall is started, and the second support member is preferably an inclined support;

[0032] S6. After the construction of the second support member 32 is completed, the first support 211 of the first foundation pit 1 is removed, the B0 plate structure is rebuilt, and the second support of the second foundation pit 2 is removed and the B1 plate structure is rebuilt;

[0033] S7. After the above steps are completed, the first support of the second foundation pit 2, the two support members and the middle partition wall above the bottom plate of the second foundation pit 2 are removed in sequence to complete the reconstruction of the B0 plate structure of the second foundation pit 2.

[0034] The above is only a description of the preferred embodiment of the present invention, and is not intended to limit the scope of protection of the present invention. Obviously, any technician familiar with the field can easily think of replacements or changes to obtain other embodiments based on the above embodiments, which should all be included in the scope of protection of the present invention.

Claims

1. A construction method for excavating adjacent foundation pits and backfilling, characterized in that: The construction steps include: S1. After the construction of the engineering piles, retaining structures, the middle wall between the two foundation pits, and the first support connecting the retaining structure and the top of the middle wall of the two adjacent foundation pits is completed, the second excavation of the first foundation pit and the second support construction of the first foundation pit are carried out. S2. After the second support of the first foundation pit is completed, the third excavation of the first foundation pit and the construction of the bottom plate of the first foundation pit are started, and the second excavation of the second foundation pit and the construction of the second support are carried out at the same time. S3. After the bottom plate of the first foundation pit is completed, a first support member is set between the bottom plate and the middle partition wall. S4. After the construction of the first support is completed, the second support of the first foundation pit is dismantled and the B1 plate structure is rebuilt. At the same time, the third layer of earthwork of the second foundation pit and the bottom plate of the second foundation pit are excavated. S5. After the B1 plate structure of the first foundation pit is rebuilt, the second support member between the B1 plate structure and the middle partition wall is constructed. S6. After the construction of the second support is completed, the first support of the first foundation pit is removed, the B0 plate structure is rebuilt, and the second support of the second foundation pit is removed and the B1 plate structure is rebuilt. S7. After the above steps are completed, the first support of the second foundation pit, the two support members and the middle partition wall above the second foundation pit bottom plate are dismantled in sequence to complete the B0 plate structure reconstruction of the second foundation pit.

2. The construction method for excavating adjacent foundation pits and backfilling according to claim 1, characterized in that: The first support member 31 in step S3 and the second support member 32 in step S5 are both oblique support members.

3. The construction method for excavating adjacent foundation pits and backfilling according to claim 2, characterized in that: The first support member 31 and the second support member 32 are both 609 steel pipes.

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