Construction method of pebble geological residence foundation sump caisson

Abstract

The invention relates to a caisson construction method for a pebble geological residence foundation sump, which comprises the following steps of: arranging wall protection steel pipes at the periphery in a foundation pit, hammering the wall protection steel pipes to be downwards inserted into a pebble bed, and stacking sandbags on the outer sides of the wall protection steel pipes to form a sandbag protection slope to prevent the foundation pit slope from collapsing and prevent fine sand from rushing into the foundation pit. Concrete is poured on the inner side of the retaining wall steel pipe through an underwater concrete self-sinking method, the caisson foundation is formed, the caisson foundation can prevent water in the lower pebble bed from flowing upwards during water pumping, and the flatness of the caisson bottom foundation is guaranteed. According to the construction method, only the water level needs to be lowered to 500 mm below the foundation raft, it can be effectively prevented that when surface water flows into the sump through the pebble bed, a foundation pit slope collapses, a foundation base needs to be cleaned many times, the foundation trench size is increased again, compared with a traditional construction method, the cost is low, the construction period is short, and the construction quality is easy to guarantee. The method is high in practicability, the labor cost and the material cost of a using unit can be reduced, and control over the construction cost, the construction period and the quality of the sump is facilitated.

Description

Technical Field

[0001] The invention relates to a water collection pit construction method, in particular to a water collection pit caisson construction method for a pebble geological residential foundation. Background Art

[0002] During construction, in order to avoid the impact of groundwater, it is generally necessary to first construct a sump to dewater the groundwater.

[0003] When constructing a water collection pit in a landslide-prone geological environment such as pebbles, the surface water is higher than the water level of the foundation pit, causing a large amount of surface water to flow into the foundation pit and wash the fine sand in the pebble layer into the foundation trench, causing the foundation pit slope to collapse and the base to be cleaned many times. At present, for water collection pits located below the water level, the basic approach is to construct a precipitation well to lower the water level to 500mm below the base of the water collection pit and then construct the water collection pit. This method takes a long time to complete and is too expensive. Summary of the invention

[0004] The purpose of the present invention is to provide a method for constructing a caisson for a sump foundation in a pebble geology residential building, so as to solve the problems of long construction period and high cost in the existing sump construction method.

[0005] The present invention is implemented in this way: a method for constructing a caisson for a water collection pit in a pebble geological residential foundation comprises the following steps.

[0006] a. When digging a sump, set up drainage pumps around the sump as backup when encountering open water to prevent the water level from being too high and causing a large-scale collapse of the foundation pit slope.

[0007] b. Set up protective wall steel pipes around the foundation pit, insert the protective wall steel pipes downward into the pebble layer, and pile sandbags on the outside of the protective wall steel pipes to form sandbag slope protection.

[0008] c. Use underwater concrete self-sinking method to pour concrete on the inner side of the wall steel pipe to form the caisson foundation.

[0009] d. Lift the caisson to the top of the sump. The caisson is prefabricated. The caisson structure includes a bottom plate and side plates. A valve is provided at the bottom of the side plates.

[0010] e. Open the valve at the bottom of the caisson and slowly lower the caisson so that it slowly sinks into the foundation pit. The water in the foundation pit flows into the caisson through the valve at the bottom of the caisson.

[0011] f. After the caisson reaches the caisson foundation, close the valve at the bottom of the caisson, put heavy objects at the bottom of the caisson as weight to prevent the caisson from floating up, set supporting steel pipes above the heavy objects inside the caisson to support the side panels of the caisson, and then fill the caisson with water.

[0012] g. Remove the sandbag slope protection outside the wall protection steel pipe and pull out the wall protection steel pipe.

[0013] h. Immediately pour concrete on the outside of the caisson and use the underwater concrete self-sinking method for construction.

[0014] i. While pouring concrete on the outside of the caisson, place a submersible pump on the outside of the caisson to pump water out to reduce the buoyancy of the water on the caisson.

[0015] j. After the concrete pouring on the outside of the caisson is completed and finally set, the water inside the caisson is pumped out, the supporting steel pipes inside the caisson are taken out, and the heavy objects inside the caisson are removed.

[0016] k. Build a brick membrane inside the caisson and then pour a concrete cushion.

[0017] l. Construct waterproof and waterproof protective layer inside the caisson.

[0018] m. Carry out reinforcement and concrete construction of sump inside caisson.

[0019] As a further improvement of the construction method of the caisson for the foundation water collection pit of a pebble geological residence of the present invention, before construction, dewatering wells are arranged around the foundation pit to lower the water level to 500 mm below the foundation raft.

[0020] As a further improvement to the construction method of the caisson for the foundation sump of a pebble geology residence of the present invention, a plurality of downwardly inclined oblique tie bars are arranged on the outer surface of the side plates of the caisson.

[0021] As a further improvement of the construction method of the caisson for the foundation sump of a pebble geological residence of the present invention, in step f, several layers of supporting steel pipes are arranged, each layer comprising several supporting steel pipes, and the supporting steel pipes are arranged crosswise.

[0022] As a further improvement of the construction method of the caisson for the sump pit of a residential foundation in pebble geology of the present invention, in step d, the caisson is hoisted to a height not exceeding 1 meter, and is slowly moved to the sinking position, and the caisson is aligned to the position by pulling ropes and supporting wooden poles.

[0023] The present invention only needs to lower the water level to 500mm below the foundation raft, and the wall steel pipe can effectively prevent the surface water from flowing into the sump through the pebble layer, causing the foundation pit slope to collapse. The base needs to be cleaned many times, and the size of the foundation trench is increased again. Compared with the traditional construction method, the cost is low and the construction period is short, and the construction quality is easy to ensure. The present invention is highly practical, can reduce the labor cost and material cost of the user unit, and is conducive to the control of the construction cost, construction period and quality of the sump. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a top view of the caisson of the present invention after being placed.

[0025] Figure 2 It is an elevation view of the caisson of the present invention after placement.

[0026] Figure 3 It is a structural diagram after pouring concrete on the outer side of the caisson of the present invention.

[0027] Figure 4 It is a structural diagram of the water collection pit construction of the present invention.

[0028] In the figure: 1. Sump; 2. Caisson; 3. Wall protection steel pipe; 4. Sandbag slope protection; 5. Caisson foundation; 6. Heavy objects; 7. Valve; 8. Support steel pipe; 9. Concrete cushion; 10. Brick membrane. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0031] like Figures 1 to 4 As shown, The present invention discloses a construction method of a water collection pit 1 and a caisson 2 for a pebble geological residential foundation, which specifically comprises the following steps.

[0032] a. When excavating the sump 1, set up 1-2 drainage pumps around the sump 1 as backup when encountering open water to prevent the water level from being too high and causing a large-scale collapse of the foundation pit slope. The base plane size of the sump 1 should be 1000mm larger than the design value.

[0033] b. Set up protective wall steel pipes 3 around the foundation pit, hammer the protective wall steel pipes 3 downward into the pebble layer, and pile sandbags on the outside of the protective wall steel pipes 3 to form sandbag slope protection 4 to prevent the foundation pit slope from collapsing and fine sand from pouring into the foundation pit.

[0034] c. Using underwater concrete self-sinking method to pour concrete inside the wall steel pipe 3 to form a caisson foundation 5. The caisson foundation 5 can prevent the water in the lower pebble layer from flowing upward when pumping water to ensure the flatness of the bottom foundation of the caisson 2.

[0035] d. Organize personnel to hoist caisson 2, lay out the longitudinal and transverse axis position lines and elevation control points on caisson 2 in advance, and calculate the sinking elevation of the elevation control point. The hoisting height of caisson 2 should not exceed 1 meter, and slowly move it to the sinking position. Under the command of the commander, the assistants align caisson 2 by pulling ropes and wooden poles.

[0036] The caisson 2 is prefabricated and comprises a bottom plate and side plates, and a valve 7 is provided at the bottom of the side plates.

[0037] e. Open valve 7 at the bottom of caisson 2, slowly lower the wire rope through the tower crane, and slowly sink caisson 2 into the foundation pit of sump 1. The water in the foundation pit of sump 1 flows into caisson 2 through valve 7 at the bottom of caisson 2. The water pressure inside and outside caisson 2 is balanced by adjusting valve 7 to ensure that caisson 2 sinks smoothly to the bottom of the foundation pit of sump 1.

[0038] f. After the caisson 2 reaches the caisson foundation 5, the valve 7 at the bottom of the caisson 2 is closed, and a weight 6 is placed at the bottom of the caisson 2. The weight 6 may be a sandbag or pebbles, which serves as a ballast to prevent the caisson 2 from floating up. A supporting steel pipe 8 is provided above the weight 6 inside the caisson 2 to support the side panels of the caisson 2, and then the caisson 2 is filled with water.

[0039] g. Take out the sandbag slope protection 4 outside the wall protection steel pipe 3 and remove the wall protection steel pipe 3.

[0040] h. Immediately pour the concrete on the outer side of caisson 2, using the underwater concrete self-sinking method. During the pouring process, special attention should be paid to not vibrate the concrete, and the concrete should be poured from one side, and then pushed forward in layers to the other side using the slurry-driving method.

[0041] i. While pouring concrete on the outside of caisson 2, a submersible pump is placed on the outside of caisson 2 to pump water outward to reduce the buoyancy of water on caisson 2. This process ensures that valve 7 is tightly closed from beginning to end, closing the channel to prevent concrete or mortar slurry from flowing into the bottom of caisson 2 or even blocking valve 7.

[0042] j. After the concrete pouring on the outer side of caisson 2 is completed and finally set, the water inside caisson 2 is pumped out, the supporting steel pipe 8 inside caisson 2 is taken out, and the weight 6 inside caisson 2 is removed to unload the internal load of caisson 2. After unloading, if the next construction process is not carried out in time, the valve 7 should be opened to maintain the balance of water pressure inside and outside caisson 2.

[0043] k. Build a brick membrane 10 in the caisson 2 and then pour a concrete cushion 9.

[0044] l. Construct waterproof and waterproof protective layers inside caisson 2.

[0045] m. Carry out steel bar and concrete construction of sump 1 in caisson 2.

[0046] As a further improvement of the construction method of the sump 1 and caisson 2 of the pebble geological residential foundation of the present invention, before construction, dewatering wells are arranged around the foundation pit to lower the water level to 500 mm below the foundation raft.

[0047] As a further improvement of the construction method of the caisson 2 for the foundation of a pebble geological residence of the present invention, a plurality of downwardly inclined inclined tie bars are arranged on the outer surface of the side plate of the caisson 2.

[0048] As a further improvement of the construction method of the sump 1 caisson 2 for a pebble geological residential foundation of the present invention, in step f, several layers of supporting steel pipes 8 are provided, each layer comprising several supporting steel pipes 8, and the supporting steel pipes 8 are arranged in a cross manner.

[0049] The present invention only needs to lower the water level to 500mm below the foundation raft, and the wall steel pipe 3 can effectively prevent the surface water from flowing into the sump 1 through the pebble layer, causing the foundation pit slope to collapse. The base needs to be cleaned many times, and the size of the foundation trench is increased again. Compared with the traditional construction method, the cost is low and the construction period is short, and the construction quality is easy to ensure. The present invention is highly practical, can reduce the labor cost and material cost of the user unit, and is conducive to the control of the construction cost, construction period and quality of the sump 1.

[0050] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, or some or all of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for constructing a caisson sump for a pebble geological residential foundation, characterized in that: The following steps are involved: a. When excavating a water collection pit, set up drainage pumps around the water collection pit as backup when encountering open water to prevent the water level from being too high and causing a large-scale collapse of the foundation pit slope; b. Set up steel pipes for wall protection around the foundation pit, insert the steel pipes downward into the pebble layer, and pile sandbags on the outside of the steel pipes to form sandbag slope protection; c. Use underwater concrete self-sinking method to pour concrete inside the wall steel pipe to form the caisson foundation; d. Lift the caisson to the top of the sump. The caisson is prefabricated. The caisson structure includes a bottom plate and side plates. A valve is provided at the bottom of the side plates. e. Open the valve at the bottom of the caisson and slowly lower the caisson so that it slowly sinks into the foundation pit. The water in the foundation pit flows into the caisson through the valve at the bottom of the caisson; f. After the caisson reaches the caisson foundation, close the valve at the bottom of the caisson, put heavy objects at the bottom of the caisson as a weight to prevent the caisson from floating up, set supporting steel pipes above the heavy objects inside the caisson to support the side plates of the caisson, and then fill the caisson with water; g. Remove the sandbags on the outside of the steel pipes for wall protection and remove the steel pipes for wall protection; h. Immediately pour the concrete on the outside of the caisson, using the underwater concrete self-sinking method for construction; i. While pouring concrete on the outside of the caisson, place a submersible pump on the outside of the caisson to pump water out to reduce the buoyancy of the water on the caisson; j. After the concrete pouring on the outside of the caisson is completed and finally set, the water inside the caisson is pumped out, the supporting steel pipes inside the caisson are taken out, and the heavy objects inside the caisson are removed; k. Lay brick membrane inside the caisson and then pour concrete cushion; l. Construct waterproof and waterproof protective layer inside the caisson; m. Carry out reinforcement and concrete construction of sump inside caisson.

2. The method for constructing a caisson sump for a pebble geological residential foundation according to claim 1, characterized in that: Before construction, drainage wells are set up around the foundation pit to lower the water level to 500mm below the foundation raft slab.

3. The method for constructing a caisson sump for a pebble geological residential foundation according to claim 1, characterized in that: A plurality of downwardly inclined inclined tie bars are arranged on the outer surface of the caisson side plate.

4. The method for constructing a caisson sump for a pebble geological residential foundation according to claim 1, characterized in that: In step f, several layers of supporting steel pipes are provided, each layer includes several supporting steel pipes, and the supporting steel pipes are arranged crosswise.

5. The method for constructing a caisson sump for a pebble geological residential foundation according to claim 1, characterized in that: In step d, the lifting height of the caisson should not exceed 1 meter, and it should be slowly moved to the sinking position, and the caisson should be aligned in position by pulling ropes and supporting wooden poles.

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