CN105178344B - The construction method of the built-in anti-float anchor rod plugging structure of sole plate precipitation of deep well - Google Patents

Abstract

The invention relates to a built-in anti-floating anchor plugging structure in a deep well dewatering well on a foundation floor, a steel casing is arranged at the head of the dewatering well, an expanded cement soil end is formed at the bottom of the dewatering well through reaming, and a capsule type anti-floating anchor is arranged in the well. The expansion end plate is set in the rod bag, and the ring-shaped positioning steel bar is arranged on the bag type anti-floating anchor rod. Anchor after sealing the steel plate; the top surface of the sealing steel plate is welded to connect the steel bars, and the bottom surface is provided with a waterproof rubber gasket, the sealing steel plate and the steel casing are connected by bolts, and the top surface of the sealing steel plate is followed by a waterproof concrete layer and a post-cast concrete closure . The invention adopts the method of built-in anti-floating anchor rod, which can reduce the damage to the dewatering wellhead due to the floating of groundwater in the later stage while ensuring the plugging quality of the wellhead, and has good economic and technical benefits.

Description

Construction method of built-in anti-floating bolt plugging structure in deep well dewatering well on foundation floor

technical field

The invention relates to a built-in anti-floating bolt plugging structure and construction method of a deep well dewatering well on a foundation floor. The utility model belongs to the field of foundation treatment and is suitable for the plugging and treatment project of the dewatering well of the building foundation.

Background technique

With the limitation of above-ground development space in cities, the utilization rate of underground space is increasing year by year and deepening. Therefore, deep foundation pits will be excavated during a large number of building constructions. In the construction of deep foundation pits, it is often encountered that dewatering wells are set in the basement of the permanent structure floor. situation. In most cases, in order to meet the requirements of the construction site, the dewatering well needs to be sealed after the construction of the bottom plate is completed. Therefore, it is inevitable for the dewatering well to pass through the cushion layer. It must become an important issue in construction.

At present, the traditional construction method is to backfill gravel concrete to the foundation cushion level immediately after the groundwater in the dewatering well is drained, and at the same time use expansive concrete with a light strength grade higher than the foundation concrete to pour to the top surface of the foundation. The disadvantage of the construction method is that it will Construction joints occur at the head of the dewatering well, which brings hidden dangers of water leakage and cannot be repaired; or use steel pipes to extend the dewatering well, pass through the foundation floor, and weld the water-stop flange on the outside of the steel pipe. The disadvantage of the construction method is that the plugging and welding time is long, and it is difficult to plug the precipitation well with a large water output.

Furthermore, in order to improve the engineering quality of the dewatering well plugging construction, there are many new types of dewatering well plugging technologies, such as a dewatering well plugging system (ZL: 201120242057.4), which uses steel pipes to extend the dewatering well and pass through For the foundation floor, the outer side of the steel pipe is welded with the water-stop flange, and at the same time, welding threaded fasteners are added to the steel pipe. When sealing, the threaded blocking plate is directly used for sealing. Although the sealing speed is relatively fast, the connection strength between the steel pipe and the dewatering well Insufficient, cracks are easy to occur when the building is unevenly settled, and the steel thread is easy to corrode, and the durability is poor; another example is a deep foundation pit dewatering well sealing structure (ZL: 201320158546.0), which extends the steel pipe into the dewatering well , using fixtures and flange sealing, and setting waterproof layer and waterproof membrane at the same time, although it has high sealing performance with the foundation bottom plate, it will cause overall blockage when the groundwater level is high and the buoyancy is too large Quality risks such as structural lifting. In addition, in the plugging construction of dewatering wells, some auxiliary plugging devices are commonly used for plugging construction, but there are defects such as complex structure, high cost, and narrow application range.

To sum up, although the existing plugging structures for dewatering wells can achieve relatively ideal plugging effects, there are still room for improvement in terms of the durability of the plugging structure, construction efficiency, anti-floating performance, and economic benefits.

In view of this, there is an urgent need to invent a deep well dewatering well plugging structure with reliable plugging quality, high anti-floating ability in the later stage, and excellent economic benefits. The construction quality of the plugging structure and the anti-floating performance of the later building foundation are greatly improved by using the anti-floating bolt plugging structure built in the deep well dewatering well in the foundation floor, and has certain economic and technical benefits.

Contents of the invention

The purpose of the present invention is to provide a deep well dewatering well built-in anti-floating bolt plugging structure and construction method with high construction efficiency, good plugging quality and strong anti-floating performance.

For realizing above-mentioned technical purpose, the present invention adopts following technical scheme:

A built-in anti-floating bolt plugging structure in the deep well dewatering well on the foundation floor, which is characterized in that a steel casing is arranged at the head of the dewatering well, the bottom of the dewatering well is expanded to form an expanded cement soil end through reaming, and a capsule type anti-floating anchor is arranged in the well. The expansion end plate is set in the rod bag, and the ring-shaped positioning steel bar is arranged on the bag type anti-floating anchor rod. Anchor after sealing the steel plate; the top surface of the sealing steel plate is welded to connect the steel bars, and the bottom surface is provided with a waterproof rubber gasket, the sealing steel plate and the steel casing are connected by bolts, and the top surface of the sealing steel plate is followed by a waterproof concrete layer and a post-cast concrete closure .

The upper opening of the steel sleeve is provided with an annular connecting steel plate, and bolt holes are reserved on the connecting steel plate; the outer wall of the steel sleeve is provided with two layers of annular waterproof steel plates, and the waterproof steel plates are respectively embedded in the foundation cushion and the foundation bottom plate.

The plugging steel plate is a round steel plate with a diameter equal to the outer diameter of the steel casing connecting steel plate, the top surface is even and vertically welded to the connecting steel bars, the anchor rod hole is reserved in the center, and the bolt hole is reserved at the edge, and the bolt hole position is consistent with the steel casing Corresponds to the bolt holes on the connecting steel plate.

The bladder type anti-floating anchor rod is a hollow steel pipe, the rod body is equidistantly provided with annular positioning steel bars, the diameter of the positioning steel bars is equal to the inner diameter of the dewatering well, and the rod body in the bag is uniformly provided with grouting holes.

The extended end plate is composed of two symmetrically arranged hinged steel plates, each hinged steel plate can be folded symmetrically up and down, the two ends of the steel plate are hingedly connected with an upper connecting ring and a lower connecting ring, the upper connecting ring is welded and fixed to the rod body, the lower The connecting ring is movable and a steel wire rope is set, and the steel wire rope is built in the rod body of the bladder type anti-floating anchor rod.

The anchor bag is made of impermeable and wear-resistant material, the two ends of the anchor bag are connected with the anchor rod by steel rings, the steel ring is fixed by a limit plate, and the limit plate is welded with the anchor rod.

The present invention also provides a construction method for the built-in anti-floating bolt plugging structure of the deep well dewatering well, the main construction steps of which are as follows:

1) Pre-construction preparation: according to the design drawings, process the construction site, draw the construction outline, make steel casings and related steel components, and put construction materials, machinery and personnel in place;

2) Temporarily fix the position of the casing: bury the steel casing at the head of the dewatering well, align it in the center, and use steel bars as the support frame to temporarily fix the steel casing;

3) Pouring cushion concrete: according to the construction requirements, pour the concrete foundation cushion. The thickness of the foundation cushion should completely cover the lower ring-shaped waterproof steel plate on the outer wall of the steel casing. mouth covering protection;

4) Concrete pouring of the outer bottom plate of the casing: pour the concrete foundation bottom plate according to the design requirements, and the lower opening of the foundation bottom plate is equal to or slightly lower than the steel casing connecting steel plate;

5) Taking out the water pump and reaming at the bottom of the dewatering well: After the floor concrete is cured, take out the water pump, and use mechanical reaming equipment to expand the holes by rotary spraying to form the anti-floating end of the grout expansion body;

6) Place the bladder-type anti-floating anchor: Slowly introduce the bladder-type anti-floating anchor into the dewatering well until the end of the anchor reaches the design elevation, the anchor bladder is completely inserted into the expanded cement soil, and the top of the anchor is temporarily reinforced fixed;

7) Grouting of the anchor bag and opening the expansion end plate: According to the design pressure and grouting volume, press and pour cement mortar to expand the anchor bag to the designed shape and size, and wait until the grouting expansion body anti-floating end reaches a certain strength Finally, pull the wire rope to open the extended end plate;

8) Backfill fine stone concrete in the dewatering well: fill the dewatering well with mortar and fine stone concrete after grouting;

9) Install the blocking steel plate: remove the temporary fixing device of the anti-floating anchor rod, and use bolts and nuts to respectively anchor the sealing steel plate and the steel casing connecting steel plate, the anti-floating anchor rod and the blocking steel plate;

10) Pouring concrete on the top of the cover plate: After the above-mentioned sealing construction is completed, a layer of waterproof concrete is first poured on the sealing steel plate. Water conservation.

The present invention has following characteristics and beneficial effect:

(1) The outer wall of the steel casing of the dewatering wellhead is provided with two layers of annular water-stop steel plates, which are embedded in the foundation cushion and the foundation floor in turn to increase the stability of the steel casing while effectively extending the seepage path of groundwater and improving the waterproofing of the sealing structure Effect.

(2) A sealing steel plate with a waterproof rubber gasket is installed on the top of the steel casing of the dewatering wellhead. Connecting steel bars are set on the sealing steel plate, and waterproof concrete and concrete closures are poured in sequence to cut off the seepage path of groundwater. At the same time, the operation is simple and the construction Low cost and good waterproof effect.

(3) The bottom of the dewatering well is reamed by means of tools, and a bladder anti-floating anchor is installed. The anchor is used as a grouting pipe for high-pressure grouting to form a grouting expansion anti-floating end, and the anchor in the bladder is set There are extended end plates, which can effectively improve the anti-floating performance of the foundation after the dewatering well is blocked, and ensure the quality of the plugged structure after construction.

Description of drawings

Fig. 1 is a schematic diagram of the built-in anti-floating bolt plugging structure of the deep well dewatering well in the foundation floor of the present invention;

Fig. 2 is a schematic diagram of the connection between the steel casing and the plugging steel plate in the present invention;

Fig. 3 is a schematic diagram of the connection between the capsule bag, the expanded end plate and the rod body of the capsule type anti-floating anchor rod of the present invention.

In the figure: 1-foundation floor, 2-foundation cushion, 3-post-cast concrete closure, 4-bolt, 5-waterproof concrete layer, 6-connecting steel bar, 7-blocking steel plate, 8-waterproof rubber gasket, 9 -Waterproof steel plate, 10-Steel casing, 11-Original dewatering well, 12-Anti-floating anchor rod, 13-Annular positioning steel bar, 14-Extended end plate, 15-Post-grouting cement-soil bearing anti-floating body, 16-Grouting Expanded anti-floating end, 17-bolt pocket, 18-expanded cement soil, 19-nut, 20-waterproof gasket, 21-steel ring, 22-limiting steel plate, 23-upper connecting ring, 24- Lower connecting ring, 25-steel wire rope.

detailed description

In this embodiment, the technical requirements for the construction of the base plate and the cushion, the technical requirements for welding construction, the ratio of the high-pressure grouting of the bladder, etc. will not be described in detail, and the construction of the anti-floating anchor plugging structure built in the deep well dewatering well involved in the present invention will be focused on implementation.

Fig. 1 is a schematic diagram of the built-in anti-floating bolt plugging structure of the deep well dewatering well in the foundation floor of the present invention; Fig. 2 is a schematic diagram of the connection between the medium steel casing and the plugging steel plate of the present invention; Schematic diagram of the connection between the pouch and the rod. Referring to Figure 1, the built-in anti-floating anchor plugging structure of the deep well dewatering well is mainly composed of steel casing 10, plugging steel plate 7, anti-floating anchor 12, and bag 17. The precipitation well 11 is taken as an example for illustration:

The steel casing 10 is made of a seamless steel pipe or a spiral welded steel pipe with a diameter of 500mm, a length of 600mm, and a thickness of 5mm. The annular waterproof steel plate 9 with a thickness of 4mm and a width of 100mm, a bolt hole with a diameter of 8mm is reserved at the place where the connecting steel plate surface is 20mm away from the edge. At the center of the upper mouth of the original dewatering well 11, a steel casing 10 is vertically buried with a depth of about 250 mm, and steel bars are used as a support frame to temporarily fix the steel casing 10.

After the steel casing 10 is temporarily fixed, according to the construction requirements, use C15 concrete to pour a foundation cushion 2 with a thickness of 100mm. On the foundation cushion 2, use C30 concrete to pour a foundation floor 1 with a thickness of 350mm~400mm. A square hole of 800 mm × 800 mm × 300 mm is left in the hanging form, and the elevation of the top of the steel casing 10 is not less than 100 mm from the elevation of the base plate 1, so as to ensure the convenient construction of the bolts for sealing the steel plate 7.

After the foundation floor 1 concrete curing is completed, the water pump is taken out, and the holes are expanded by rotary spraying with a mechanical reaming machine to form an expanded cement soil 18 with a diameter of about 1200mm, and then the bladder-type anti-floating anchor rod 12 with an inner diameter of 25mm and a wall thickness of 6mm is slowly introduced into the dewatering well Until the lower end of the anti-floating anchor 12 reaches the design elevation, the bladder 17 is fully inserted into the expanded cement soil 18, and the top of the anti-floating anchor 12 is temporarily fixed with a steel frame. Wherein the bladder 17 is made of polyester long fiber composite material, and is connected with the anti-floating anchor rod 12 through a steel ring 21, and the steel ring 21 is fixed by a limiting steel plate 22 welded on the surface of the anchor rod.

According to the design pressure and the amount of grouting, pressurize the cement mortar to expand the bladder 17 into a grouting expanded anti-floating end 16 with a diameter of about 800mm. After the cement mortar in the bladder 17 reaches a certain strength, pull the steel wire rope 25 to open it. The extended end plate 14, wherein the single hinged steel plate of the extended end plate 14 is hinged by two small steel plates with a specification of 600mm×400mm.

After the grouting is completed, use cement mortar to backfill the original dewatering well 11 to form the post-grouting cement-soil bearing anti-floating body 15. When backfilling to 300mm below the level of the foundation cushion 2, replace C30 concrete pouring, pouring to about 50mm below the top of the steel casing 10 After the completion, the temporary fixing device of the anti-floating anchor 12 is removed, and the bolt 4 and the waterproof rubber washer 8 are used to anchor the sealing steel plate and the steel casing connecting steel plate, and the anti-floating anchor 12 is anchored to the sealing steel plate 7 by using the nut 19 , Install the waterproof gasket 20 before the nut 19 is anchored. A bolt hole with a diameter of 25mm is reserved in the center of the plugging steel plate 7, bolt holes with a diameter of 8mm corresponding to the steel casing 10 are reserved around, and the top surface is uniform and vertically welded with a threaded steel bar 6 with a length of 80mm.

After the above-mentioned sealing construction is completed, a waterproof concrete layer 5 with a thickness of 100mm is first poured on the sealing steel plate, and then the expanded concrete is used for secondary pouring to form a post-cast concrete closure 3, and finally the top is covered with wet sacks or straw bags , for no less than 14 days of wet curing.

The main construction steps of the anti-floating bolt plugging structure built in the deep well dewatering well are as follows:

1) Preparation before construction: According to the design drawings, process the construction site, draw the construction outline, make steel casing 10 and related steel components, and place construction materials, machinery and personnel in place;

2) Temporarily fix the position of the steel casing: bury the steel casing 10 at the head of the dewatering well, align it in the center, and use steel bars as a support frame to temporarily fix the steel casing 10;

3) Pouring cushion concrete: pour concrete foundation cushion 2 according to the construction requirements. The thickness of the foundation cushion 2 should completely cover the outer wall of the steel casing 10 and the lower circular waterproof steel plate 9. Covering and protecting the upper opening of the steel casing 10;

4) Concrete pouring for the outer bottom plate of casing: pour concrete foundation bottom plate 1 according to the design requirements, the lower opening of foundation bottom plate 1 is equal to or slightly lower than the connecting steel plate of steel casing pipe 10, and the allowable deviation is ±10mm;

5) Taking out the water pump and reaming at the bottom of the dewatering well: After the concrete curing of the foundation floor 1 is completed, take out the water pump, and use mechanical reaming equipment to expand the holes by rotary spraying to form the anti-floating end 16 of the grouting expansion body;

6) Place the bladder-type anti-floating anchor: Slowly introduce the bladder-type anti-floating anchor 12 into the original dewatering well 11 until the end of the anti-floating anchor 12 reaches the design elevation, and the anchor bag 17 is completely inserted into the expanded cement soil 18 , the top of the anti-floating anchor rod 12 is temporarily fixed with a reinforcement frame;

7) Grouting of the anchor bag and opening of the extended end plate: according to the design pressure and grouting volume, the cement mortar is press-filled to expand the anchor bag 17 to the designed shape and size. After a certain strength, pull the wire rope 25 to open the extended end plate 14;

8) Backfill fine stone concrete in the dewatering well: after the grouting is completed, fill the original dewatering well 11 with cement mortar and fine stone concrete;

9) Install the blocking steel plate: remove the temporary fixing device of the anti-floating anchor rod 12, and use bolts 4 and nuts 19 to respectively anchor the sealing steel plate 7 and the steel casing 10 connecting steel plate, the anti-floating anchor rod 12 and the blocking steel plate 7;

10) Pouring concrete on the upper part of the cover plate: After the above-mentioned sealing construction is completed, a layer of waterproof concrete is first poured on the sealing steel plate 7, and the waterproof concrete layer 5 completely covers the vertical connecting steel bars 6, and then pours expansive concrete to fill it tightly. Water storage and maintenance after initial setting.

Claims (1)

1. A construction method for the built-in anti-floating bolt plugging structure of the deep well dewatering well in the foundation floor, characterized in that, the dewatering well head is provided with a steel casing, the bottom of the dewatering well forms an expanded cement soil end by reaming, and a capsule type is set in the well. Anti-floating anchor, the anchor bag is equipped with an extended end plate, and the bladder anti-floating anchor is equipped with a ring-shaped positioning steel bar. After the anchor bag is inserted into the expanded cement soil, the grouting expanded anti-floating end is formed by high-pressure grouting , the upper end of the anchor rod is anchored after passing through the sealing steel plate; the top surface of the sealing steel plate is welded to connect the steel bars, and the bottom surface is provided with a waterproof rubber gasket, and the sealing steel plate is connected with the ring-shaped connecting steel plate on the upper opening of the steel casing by bolts, and the top of the sealing steel plate The surface is a waterproof concrete layer and a post-cast concrete closure in turn, and the outer wall of the steel casing is provided with two layers of annular waterproof steel plates; The construction steps of described construction method are as follows: 1) Pre-construction preparation: according to the design drawings, process the construction site, draw the construction outline, make steel casings and related steel components, and put construction materials, machinery and personnel in place; 2) Temporarily fix the position of the steel casing: bury the steel casing at the head of the dewatering well, align it in the center, and use steel bars as the support frame to temporarily fix the steel casing; 3) Pouring cushion concrete: according to the construction requirements, pour the concrete foundation cushion. The thickness of the foundation cushion should completely cover the lower ring-shaped waterproof steel plate on the outer wall of the steel casing. mouth covering protection; 4) Concrete pouring of the outer bottom plate of the steel casing: pour the concrete foundation bottom plate according to the design requirements, and the lower opening of the foundation bottom plate is equal to or slightly lower than the connecting steel plate of the steel casing; 5) Taking out the water pump and reaming at the bottom of the dewatering well: After the floor concrete is cured, take out the water pump, and use a mechanical reaming machine to expand the hole by rotary spraying to form a grouting expansion body anti-floating end; 6) Install the bladder-type anti-floating anchor: Slowly introduce the bladder-type anti-floating anchor into the dewatering well until the end of the anchor reaches the design elevation, the anchor bag is completely inserted into the expanded cement soil, and the top of the anchor is temporarily fixed with a steel frame ; 7) Grouting of the anchor bag and opening the expansion end plate: According to the design pressure and grouting volume, press and pour cement mortar to expand the anchor bag to the designed shape and size, and wait until the grouting expansion body anti-floating end reaches a certain strength Finally, pull the wire rope to open the extended end plate; 8) Backfill fine stone concrete in the dewatering well: fill the dewatering well with mortar and fine stone concrete after grouting; 9) Install the blocking steel plate: remove the temporary fixing device of the anti-floating anchor rod, and use bolts and nuts to respectively anchor the sealing steel plate and the steel casing connecting steel plate, the anti-floating anchor rod and the blocking steel plate; 10) Pouring concrete on the upper part of the sealing steel plate: After the above sealing construction is completed, a layer of waterproof concrete is first poured on the sealing steel plate, the waterproof concrete layer completely covers the vertical connecting steel bars, and then the expansive concrete is poured. Post water conservation.