CN116927204A - Suitable for deep foundation pit underground diaphragm wall reverse construction method and lining wall inter-layer slope treatment method - Google Patents

Abstract

The invention discloses a method for processing a slope between lining walls in a reverse construction method of a deep foundation pit underground diaphragm wall, which relates to the technical field of hydraulic engineering and comprises the following steps of S10, roughening the underground diaphragm wall, and binding a capping beam and steel bars of the lining walls in the deep foundation pit; s20, excavating until the elevation of the lining concrete of the layer is lower than that of the lining concrete, and installing a longitudinal main rib; s30, backfilling with medium coarse sand to a preset height below the elevation of the substrate in the layer; s40, filling fine stone concrete to form an interlayer slope, and pouring concrete on the laminated top beam and the lining wall; s50, removing the mould and chiseling the fine stone concrete part after the preset condition is reached to enable the middle coarse sand to fall off; s60, repeating the steps S10-S50 to perform lining wall construction in the lower layer. The construction method is simple and convenient to operate, quality can be guaranteed, construction progress is processed, and construction cost is saved.

Description

Suitable for deep foundation pit underground diaphragm wall reverse construction method and lining wall inter-layer slope treatment method

Technical field

The invention relates to the technical field of water conservancy engineering, and in particular to a method for treating slopes between layers of lining walls using reverse construction of continuous walls in deep foundation pits.

Background technique

With the rapid development of my country's national economy and the increasing shortage of national land resources, many high-rise buildings, subways, water diversion projects, etc. have deep foundation pit construction. Especially in the southern region, where groundwater is abundant, the retaining structure of deep foundation pits is mostly underground. In the form of a continuous wall combined with a lining wall, the quality of the interlayer bonding of the lining wall is directly related to the safety of internal excavation and concrete construction of the foundation pit. In order to ensure the bonding effect between layers, prevent water seepage between layers, and ensure the safety of foundation pit excavation, the bottom of the lining wall, that is, the joint surface of the upper and lower lining walls, generally adopts the form of a slope. The cross-section shape of each layer of lining wall is parallelogram. The existing technology is to fabricate steel bars and install water-proofing between layers according to the design drawings. Large steel formwork is used for the side walls, and wooden formwork is used for the bottom formwork. The vertical steel bars are drilled through the formwork to ensure that they pass through to the lower excavation layer. In the existing technology, due to the narrow space of the lining wall, it is difficult to install the formwork, and the formwork needs to be drilled, which requires higher process requirements and it is difficult to ensure quality.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for processing the inter-layer slope of the lining wall using the reverse construction method of the underground diaphragm wall in deep foundation pits, which can effectively solve the difficulty of installing wooden formwork in the narrow space of the lining wall, the construction complexity, and the need for chiseling. Holes have higher process requirements.

The technical solution adopted by the present invention to solve the technical problem is: the method for treating the slope between layers of the lining wall by reverse construction of the diaphragm wall in the deep foundation pit, including the following steps:

S10. Carry out roughening treatment on the underground diaphragm wall, and tie the steel bars of the top beam and the lining wall of this layer;

S20. Excavate to below the elevation of the concrete lining of this layer, and install longitudinal main bars;

S30. Use medium-coarse sand to backfill to the preset height below the elevation of the inner lining of this layer;

S40. Fill with fine stone concrete to form an inter-layer slope, and pour concrete for the laminated roof beam and lining wall;

S50. After reaching the preset conditions, remove the formwork and chisel away the fine stone concrete part to make the medium-coarse sand fall off;

S60. Repeat steps S10-S50 to construct the lower lining wall.

Further, step S10 also includes a preprocessing step,

Based on the completed underground diaphragm wall, carry out deep foundation pit dewatering well, retaining wall, water supply and drainage construction;

Break the underground diaphragm wall pile heads from top to bottom and dig out the preset height of the underground diaphragm wall.

Further, the preset height is 500mm.

Further, in step S20, the longitudinal main ribs are protected by plastic film or PVC pipes.

Further, in step S20, the excavation is carried out to at least 1000 mm below the elevation of the lining concrete of the current layer.

Further, the preset height in step S30 is 100 mm.

Further, in step S40, concrete is poured on the laminated roof beam and the lining wall, including

When pouring concrete, two pump trucks are used for symmetrical pouring. The pouring should be in layers, and the pouring height of each layer should not be greater than 500mm.

Further, in step S50, the conditions for removing the concrete form after reaching the preset conditions are: removing the formwork after the strength of the concrete reaches 80% of the design strength.

Further, in step S50, the fine stone concrete part is chiseled off to make the medium-coarse sand fall off, including

Use a pneumatic pick to chisel away the fine stone concrete, and the medium-coarse sand at the bottom will naturally fall off.

This method is suitable for the reverse construction method of underground diaphragm walls in deep foundation pits. When excavating deep foundation pits, excavate to below the elevation of the lining concrete layer, and then install the longitudinal main bars. After the main bars are installed, use medium-thick Sand is backfilled to a preset height below the design elevation of the inner substrate, and then fine stone concrete is used to form an inter-layer slope. After the concrete reaches the design strength, the fine stone concrete is chiseled off, and the medium-coarse sand at the bottom will naturally fall off, and the rough surface effect of the contact surface between layers can also be guaranteed. The construction method is easy to operate, and can ensure quality, process the construction progress, and save construction costs. .

Description of the drawings

The present invention will be further described below in conjunction with the accompanying drawings and examples. In the accompanying drawings:

Figure 1 is a flow chart of the method according to the embodiment of the present invention;

Figure 2 is a structural schematic diagram corresponding to the construction procedure of the embodiment of the present invention;

Figure 3 is a schematic structural diagram corresponding to the construction procedure of the embodiment of the present invention;

Figure 4 is a schematic structural diagram corresponding to the construction procedure of the embodiment of the present invention.

Detailed ways

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

This method is suitable for the reverse construction method of underground diaphragm walls in deep foundation pits and the inter-layer slope treatment method of lining walls. The overall process flow is: underground diaphragm wall construction → dewatering well and retaining wall construction → underground diaphragm wall pile head breaking → top beam pressing and first The steel bars of the lining wall are tied → the slope between the upper and lower floors of the lining wall is processed → the concrete is poured → the formwork is removed → the roughening between the layers is processed → enter the next cycle.

Refer to Figure 1-4, which shows the specific construction details of each step and the structural schematic diagram of the corresponding process. This method is suitable for the reverse construction method of underground diaphragm walls in deep foundation pits and the inter-layer slope treatment method of lining walls, including the following steps:

S10. Carry out roughening treatment on the underground diaphragm wall, and tie the steel bars of the top beam and the lining wall of this layer. Of course, there is also a preprocessing step before this step,

Based on the completed underground diaphragm wall, carry out deep foundation pit dewatering well, retaining wall, water supply and drainage construction;

Break the pile heads of the underground diaphragm wall from top to bottom, and dig out the preset height of the underground diaphragm wall, where the preset height is 500mm.

S20. Excavate to below the elevation of the concrete lining of this layer, and install longitudinal main bars. Specifically, the excavation is carried out to at least 1000mm, preferably 1050mm, below the elevation of the lining concrete of this layer, and the longitudinal main bars are preferably protected by plastic films or PVC pipes.

S30. Use medium-coarse sand to backfill to 100mm below the elevation of the inner lining of this layer.

S40. Use fine stone concrete to fill the inter-layer slopes, and concrete the laminated roof beams and lining walls; use two pump trucks to pour the concrete symmetrically. The pouring should be in layers, and the pouring height of each layer should not be greater than 500mm.

S50. After the concrete strength reaches 80% of the design strength, remove the formwork and use a pneumatic pick to remove the fine stone concrete part. The medium-coarse sand will naturally fall off.

S60. Repeat steps S10-S50 to construct the lower lining wall. That is, the earth and rockwork of the lower foundation pit is excavated to the design elevation, and the lower lining wall construction is carried out according to the above steps.

This method is suitable for the reverse construction method of underground diaphragm walls in deep foundation pits. When excavating deep foundation pits, excavate to below the elevation of the lining concrete layer, and then install the longitudinal main bars. After the main bars are installed, use medium-thick Sand is backfilled to a preset height below the design elevation of the inner substrate, and then fine stone concrete is used to form an inter-layer slope. After the concrete reaches the design strength, the fine stone concrete is chiseled off, and the medium-coarse sand at the bottom will naturally fall off, and the rough surface effect of the contact surface between layers can also be guaranteed. The construction method is easy to operate, and can ensure quality, process the construction progress, and save construction costs. .

Finally, it should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that these entities or any such actual relationship or sequence between operations. Furthermore, the terms "comprises," "comprises," or any other variations thereof are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also those not expressly listed other elements, or elements inherent to the process, method, article or equipment. Without further limitation, an element defined by the statement "comprises a..." does not exclude the presence of additional identical elements in a process, method, article, or apparatus that includes the stated element.

Obviously, the above-mentioned embodiments are only examples for clear explanation and are not intended to limit the implementation. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. An exhaustive list of all implementations is neither necessary nor possible. The obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims (9)

1. It is suitable for the reverse construction method of underground diaphragm walls in deep foundation pits and is a method for treating inter-layer slopes of lining walls. It is characterized by including the following steps: S10. Carry out roughening treatment on the underground diaphragm wall, and tie the steel bars of the top beam and the lining wall of this layer; S20. Excavate to below the elevation of the concrete lining of this layer, and install longitudinal main bars; S30. Use medium-coarse sand to backfill to the preset height below the elevation of the inner lining of this layer; S40. Fill with fine stone concrete to form an inter-layer slope, and pour concrete for the laminated roof beam and lining wall; S50. After reaching the preset conditions, remove the formwork and chisel away the fine stone concrete part to make the medium-coarse sand fall off; S60. Repeat steps S10-S50 to construct the lower lining wall. 2. The method for treating inter-layer slopes of lining walls using the reverse construction method for underground diaphragm walls in deep foundation pits according to claim 1, characterized in that step S10 also includes a preprocessing step, Based on the completed underground diaphragm wall, carry out deep foundation pit dewatering well, retaining wall, water supply and drainage construction; Break the underground diaphragm wall pile heads from top to bottom and dig out the preset height of the underground diaphragm wall. 3. The method for treating inter-layer slopes of lining walls by reverse construction of underground diaphragm walls in deep foundation pits according to claim 2, characterized in that the preset height is 500mm. 4. The interlayer slope treatment method suitable for reverse construction of underground continuous walls in deep foundation pits and lining walls according to claim 1, characterized in that in step S20, the longitudinal main bars are protected by plastic films or PVC pipes. 5. The method for treating the inter-layer slope of the lining wall using the reverse construction method of the underground diaphragm wall in deep foundation pits according to claim 1, characterized in that in step S20, the excavation is carried out to at least 1000 mm below the elevation of the lining concrete of the current layer. 6. The method for treating the inter-layer slope of the lining wall by the reverse construction method of the underground diaphragm wall in deep foundation pits according to claim 1, characterized in that the preset height in step S30 is 100mm. 7. The method for processing the inter-layer slope of the lining wall using the reverse construction method of the underground diaphragm wall in the deep foundation pit according to claim 1, characterized in that in step S40, concrete pouring is performed on the laminated top beam and the lining wall, including When pouring concrete, two pump trucks are used for symmetrical pouring. The pouring should be in layers, and the pouring height of each layer should not be greater than 500mm. 8. The method for treating inter-layer slopes of lining walls using the reverse construction method of underground diaphragm walls in deep foundation pits according to claim 1, characterized in that, in step S50, the conditions for removing the formwork concrete after reaching the preset conditions are: concrete Remove the formwork after the strength reaches 80% of the design strength. 9. The interlayer slope treatment method suitable for reverse construction of underground continuous walls in deep foundation pits and lining walls according to claim 1, characterized in that in step S50, the fine stone concrete part is chiseled off to cause the medium-coarse sand to fall off, including Use a pneumatic pick to chisel away the fine stone concrete, and the medium-coarse sand at the bottom will naturally fall off.