CN215053282U - Pre-grouting water stop structure of water-rich silt stratum suitable for connection construction of underground building - Google Patents

Abstract

The utility model discloses a pre-grouting stagnant water structure in rich water silt stratum suitable for connection construction of underground structure adopts the form of all slip casting shutoff through the structure inboard, including interface bottom plate drilling slip casting stagnant water and interface side wall drilling slip casting stagnant water, seals the percolating water passageway that probably exists to prevent foundation ditch bottom plate, side wall rivers exosmosis in advance. The method specifically comprises the following steps: (1) excavating the foundation pit to a position 1m away from the underground water level after precipitation; (2) grouting the bottom plate of the in-pit interface; (3) grouting a steel floral tube of a side wall of the inner joint of the pit; (4) and (5) blocking soil between piles. The utility model discloses a structure of slip casting in advance is driped a hole to the side wall and the bottom plate of underground structure connection interface has the prevention earlier, sets up defences layer upon layer, both controls to subside and control the percolating water, falls to the construction risk minimum, reduces the characteristics of maintenance cost.

Description

Pre-grouting water stop structure of water-rich silt stratum suitable for connection construction of underground building

Technical Field

The utility model relates to a to new and old station cross transfer node or underground structure connection construction prevent gushing water technical field, specifically be a water-rich silt stratum's slip casting stagnant water structure in advance.

Background

With the development of society, especially the progress of science and technology, the rapid social productivity is greatly promoted, especially the development of transportation industry, and the radius of life and the life style of people are greatly changed. Among many transportation means, subways play an increasingly important role in human life. The subway can quickly, safely and comfortably transport passengers with large flow, and has good social and economic benefits, so that the urban subway construction is developed rapidly in recent years. However, because the subway construction is carried out underground, the underground structure is greatly influenced by the hydrogeological environment, huge construction safety risks exist in the construction process of the subway civil engineering, the underground construction safety risks are easily influenced by water seepage of the underground enclosure structure, and particularly when the enclosure structure is an underground continuous wall, the hidden danger of water seepage at the joint is larger.

At present, in the subway construction process, foundation pit engineering risk control is mainly focused on water treatment, particularly deep foundation pits, once water leakage occurs in the foundation pits, water gushing and sand gushing channels can be formed, a large amount of water and soil loss outside the pits can be accompanied, and if the water and soil loss is not blocked in time, serious consequences can be generated. Particularly, when a deep foundation pit is excavated in a water-rich silt stratum, water gushing and sand gushing accidents are more easily caused, great influence is caused on surrounding buildings, pipelines and roads, if water gushing and sand gushing occur in the foundation pit, effective control cannot be achieved in a short time, once a water gushing and sand gushing channel is formed, ground collapse is caused, and the pipeline and the residential community are affected. In the planning of the subway line network, in order to facilitate the four-way and eight-way subway, the line design is generally designed to be crossed with one or more lines, so that various transfer modes such as parallel transfer, cross transfer and the like are formed among the lines. Therefore, in the new line construction project, connection construction with the existing line is inevitable. Construction risks of a line under construction, such as displacement, floating, water gushing and sand gushing at an interface part caused by foundation pit excavation, influence traffic operation of an existing line, the risks are generally I-type risks, and the important significance is achieved in researching how to solve the problems.

Therefore, the pre-grouting water stopping structure of the water-rich silt stratum is provided, can be suitable for water stopping support of cross transfer nodes of new and old stations of the water-rich silt stratum or connection construction of underground building structures, and is a problem which needs to be solved urgently.

Disclosure of Invention

In order to solve the above-mentioned prior art exist not enoughly, the utility model provides a pre-grouting stagnant water structure on rich water silt stratum solves the water problem of gushing in new and old station cross transfer node or the underground structure connection construction.

The purpose of the utility model is realized like this:

a pre-grouting water stop structure of a water-rich silt stratum adopts a form of all-around grouting plugging on the inner side of a connecting structure, comprises a connector bottom plate drilling grouting water stop structure and a connector side wall drilling grouting water stop structure, seals a possibly existing leakage water channel, and inhibits uneven settlement of the structure;

the interface bottom plate drilling grouting water stop structure is used for plugging an exposed steel sheet welded between piles; the fender post is provided with an expansion bolt which is firmly welded with the thin steel plate or adopts a structure of hanging net and spraying concrete.

The interface side wall drilling grouting water stop structure is characterized in that vertical back grouting reinforcement processing is carried out on the position between piles of the existing enclosure structure, and grouting interface positions are located on two sides of the structure; the joint side wall drilling grouting water stopping is to arrange a steel perforated pipe between the enclosure piles for grouting reinforcement.

Performing vertical retreating type grouting to a grouting gallery in a pile position gap; the drilling depth is the same as the reinforcing depth of the original water-stop curtain of the triaxial mixing pile, and the grouting depth of the double-liquid slurry is from the bottom plate of the foundation pit to the bottom of the pile.

The steel perforated pipe is dug once every 3m to the base by adopting double-liquid slurry along with excavation, and the overlapped grouting part is ensured to be not less than 1 m.

The steel perforated pipe is made of hot-rolled seamless steel pipes with the pipe diameter phi of 42mm, drilling and grouting holes are formed in the steel perforated pipe, the hole diameter phi is 6-8 mm, the hole spacing is 10-30 cm, the steel perforated pipe is arranged in a quincunx shape, the front end of the steel perforated pipe is processed into a cone, and the tail part of the steel perforated pipe is 60cm in length;

the drilling depth of the steel perforated pipe is generally 4-6 m, and the external insertion angle is 16-19 degrees.

Has the positive and beneficial effects that: the utility model discloses a stagnant water structure is earlier through the prevention, and the technology of seting up defences layer upon layer, both control subsides and control the percolating water, falls the construction risk to minimumly, reduces the characteristics of maintenance cost, and the economy and the social that obtain are unable to measure.

Drawings

FIG. 1 is a flow chart of the construction method of the utility model:

FIG. 2 is a schematic diagram of a planar structure of slurry injection in a pit according to an embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of slurry injection in a pit according to an embodiment of the present invention;

FIG. 4 is a schematic view of the grouting reinforcement of the steel perforated pipe between piles in the embodiment of the present invention;

FIG. 5 is an enlarged view of a portion of the structure of FIG. 4;

in the figure, the following steps are carried out: the device comprises a connector 1, in-pit grouting holes 2, a triaxial mixing pile 3, a grouting gallery 4, a bored pile 5 and a steel perforated pipe 6.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings and embodiments:

in the embodiment of the utility model, a pre-grouting water stop structure for water-rich silt stratum adopts the form of all-around grouting plugging in the inner side of the connecting structure, including the interface bottom plate drilling grouting water stop structure and the interface side wall drilling grouting water stop structure, to close the possible leakage water channel and inhibit the structure from non-uniform settlement;

as shown in fig. 2, the grouting and water stopping of the interface bottom plate are implemented by performing vertical back grouting reinforcement treatment on the existing position between the piles of the building envelope, and the grouting position is located at the interface 1 on the two sides of the structure.

As shown in fig. 3, when the excavation is carried out to a distance of 1m from the underground water level, the original enclosure structures (the bored pile 5 and the triaxial mixing pile 3) are all broken in place, and vertical retreating grouting is carried out in the pile position gap to the grouting gallery 4. The drilling depth is the same as the reinforcing depth of the original water-stop curtain of the triaxial mixing pile, and the grouting depth of the double-liquid slurry is from the bottom plate of the foundation pit to the bottom of the pile.

As shown in fig. 3, the grouting and water stopping of the side wall of the connector are implemented by grouting and reinforcing steel perforated pipes among the enclosure piles, the steel perforated pipes are dug once every 3m to the foundation by adopting double-fluid slurry along with excavation, and the overlapped grouting part is ensured to be not less than 1 m.

As shown in fig. 4 and 5, the steel perforated pipe 6 with a diameter phi of 42mm is made of a hot-rolled seamless steel pipe, grouting holes are drilled in the pipe, the diameter phi of the holes is 6-8 mm, the hole spacing is 10-30 cm, the pipe is arranged in a quincunx shape, the front end of the pipe is processed into a cone, and the tail part of the pipe is 60cm in length; the hole depth of the steel perforated pipe is generally 4-6 m, and the external insertion angle is 16-19 degrees.

When bottom plate grouting is carried out, grouting can be started only after the grout is fully and uniformly stirred by a stirrer, the grout is slowly stirred without stopping in the grouting process, and the grout is filtered by a screen before being pumped; grouting construction should be carried out by jumping holes, and the grout outlet condition of the grouting holes is observed; and (3) stopping grouting immediately when the grout bleeding phenomenon occurs in the middle of grouting, investigating the cause of the grout bleeding, and taking measures in time.

As shown in fig. 1, the utility model also provides a construction method at rich water silt stratum preliminary slip casting stagnant water, construction method divide into interface bottom plate slip casting construction method and interface side wall slip casting construction method, respectively as follows:

the grouting construction method for the interface bottom plate comprises the following steps:

(1) construction preparation: excavating to a position 1m away from the underground water level, cleaning a field area, leveling the field, entering a drilling machine and matched equipment for debugging, electrically connecting water and electricity to a construction site and installing a valve;

(2) pile position measurement: the cast-in-place bored pile and the triaxial mixing pile in the original enclosure structure are broken in place, a total station is used for measuring the grouting hole position of the pile position gap, a drilling machine is used for guiding holes, and retesting is carried out, so that the central displacement deviation of the pile hole is ensured to be less than 50 mm;

(3) positioning a drilling machine: after the drilling machine is in place, leveling and centering the pile machine, adjusting the perpendicularity of the pile machine and ensuring that the error of the perpendicularity of the drilled hole is less than 1.0% H; before drilling, a water pump, an air compressor and a grouting machine are required to be debugged, so that the equipment can normally operate;

(4) drilling: after the drilling machine is normally operated, switching on an air compressor, controlling the pressure of compressed air to be 0.8-1.0 Mpa, and rotationally drilling the drilling machine under the action of the impact force of the compressed air;

(5) preparing materials and pulping: the water-cement ratio of the slurry is =1:0.5 (mass ratio), and the double-liquid slurry for 1m plantation is prepared by 4 bags of cement (200 kg of Portland #425 cement) according to the actual mixture ratio on site; water glass (35 ° B) and cement slurry =1:1 (volume ratio) were subjected to postgrouting at a grouting rate: 15-20L/min, grouting pressure: 0.8-1.5 Mpa;

the mixing ratio of the slurry is liquid A (mass ratio) water to cement (42.5 ordinary portland cement) =1:0.5, and liquid B adopts water glass (35 DEG Be); wherein, the ratio of the A solution to the B solution is =1:1 (volume ratio); in actual construction, the proportion of the cement and the water glass double-slurry can be adjusted according to specific requirements;

(6) grouting and lifting: and after the drilling machine drills to the designed depth, inserting the spray pipe, connecting the grouting pump, grouting from bottom to top, and simultaneously cleaning and discharging the slurry. When spraying, the preset spraying pressure is reached, and then the grouting pipe is gradually lifted after spraying to prevent the spray pipe from being twisted off. In order to ensure the reinforcing quality, when the nozzle sinks to the designed depth, the nozzle rotates at the original position for about 10 seconds, and the nozzle is lifted by rotary spraying after the orifice bleeds normally;

(7) shifting a drilling machine, and recharging slurry: stopping grouting when the grouting is lifted to the designed elevation, lifting the drill bit outlet, cleaning the grouting pump and conveying

The pipeline, then the drilling machine is shifted, and the slurry is refilled;

(8) checking and accepting the visa: after the work is finished, the site supervision engineer is requested to confirm and check the qualification.

The grouting construction method for the interface side wall comprises the following steps:

(1) construction preparation: excavating to a position 1m away from the underground water level, cleaning a field area, leveling the field, entering and debugging a spiral drilling machine and matched equipment, electrically connecting water and electricity to a construction site, installing valves and preparing steel perforated pipes;

(2) drilling: drilling by a drilling machine or directly driving by an air pick, wherein the hole depth is generally 4-6 m, and the external insertion angle is 16-19 degrees;

(3) slurry preparation: liquid A (mass ratio) = water: cement (42.5 ordinary portland cement) = 1.5: 1; liquid B (volume ratio) = water glass (40 DEG Be): water =2: 1; and finally, adopting grouting proportion on site: liquid A and liquid B =1:1 (volume ratio); and (3) preparing the double-liquid slurry for 1m by using 4 bags of cement (200 kg of ordinary Portland 425 cement) according to the actual on-site proportioning. In actual construction, the proportion of the cement and the water glass double-slurry can be adjusted according to specific requirements;

(4) grouting: and welding a valve after the steel perforated pipe is drilled into a soil layer, controlling the grouting pressure to be 1.5MPa, and closing the valve to stop grouting when the grouting pressure of a pressure gauge exceeds 2MPa or the grout runs on the surface of the substrate. Grouting records are formed in time during construction, excavation is carried out after grouting is considered to reach the finishing standard through statistics of the grouting records, the diffusion condition of grout is observed in the excavation process, the cause of problems is analyzed, and preparation is made for next circulation grouting;

(5) plugging soil between piles: and (5) after grouting, downward excavating, and plugging the exposed inter-pile soil welding thin steel plate. The fender post is provided with expansion bolts which are firmly welded with the steel plate or blocked by adopting a mode of hanging net and spraying concrete, so that water and sand gushing among the posts caused by insufficient grouting can be prevented.

The utility model adopts the prevention that the rings of each process are buckled with each other to set up defences layer by layer, can effectively protect the structure, fully exerts the advantages of the grouting technology, and can control both the leakage water and the settlement; the construction risk is reduced, the structure maintenance cost is reduced, and inestimable economic and social benefits are obtained.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing embodiments, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (5)

1. The utility model provides a pre-grouting stagnant water structure in rich water silt stratum that is applicable to the connection construction of underground structure, its characterized in that: the inner side of the connecting structure is blocked by adopting full grouting, and the connecting structure comprises a connector bottom plate drilling grouting water stop structure and a connector side wall drilling grouting water stop structure, so that a possibly existing water leakage channel is closed, and the uneven settlement of the structure is inhibited;

the interface bottom plate drilling grouting water stop structure is used for plugging an exposed steel sheet welded between piles; the fender post is provided with an expansion bolt which is firmly welded with the thin steel plate or adopts a structure of hanging net and spraying concrete;

the interface side wall drilling grouting water stop structure is characterized in that vertical back grouting reinforcement processing is carried out on the position between piles of the existing enclosure structure, and grouting interface positions are located on two sides of the structure; the joint side wall drilling grouting water stopping is to arrange a steel perforated pipe between the enclosure piles for grouting reinforcement.

2. The structure of claim 1, wherein the structure comprises: performing vertical retreating type grouting to a grouting gallery in a pile position gap; the drilling depth is the same as the reinforcing depth of the original water-stop curtain of the triaxial mixing pile, and the grouting depth of the double-liquid slurry is from the bottom plate of the foundation pit to the bottom of the pile.

3. The structure of claim 1, wherein the structure comprises: the steel perforated pipe is dug once every 3m to the base by adopting double-liquid slurry along with excavation, and the overlapped grouting part is ensured to be not less than 1 m.

4. The structure of claim 1 or 3, wherein: the steel perforated pipe is made of hot-rolled seamless steel pipes with the pipe diameter phi of 42mm, drilling and grouting holes are formed in the pipe, the hole diameter phi is 6-8 mm, the hole distance is 10-30 cm, the pipe is arranged in a quincunx shape, the front end of the pipe is processed into a cone shape, and the tail length of the pipe is 60 cm.

5. The structure of claim 1 or 3, wherein: the drilling depth of the steel perforated pipe is generally 4-6 m, and the external insertion angle is 16-19 degrees.

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