CN113585370A

CN113585370A - Plugging method for core-pulling hole

Info

Publication number: CN113585370A
Application number: CN202110879254.5A
Authority: CN
Inventors: 刘伟; 彭卫平; 温忠义; 张庆华; 刘志方; 陈倩岚
Original assignee: Guangzhou Urban Planning Survey and Design Institute
Current assignee: Guangzhou Urban Planning Survey and Design Institute
Priority date: 2021-07-30
Filing date: 2021-07-30
Publication date: 2021-11-02

Abstract

The invention discloses a core-pulling hole plugging method, which comprises the following steps: s1, forming a plugging groove along the periphery of the opening of the core-pulling hole; s2, inserting a plugging sleeve into the core-pulling hole, enabling the upper part of the plugging sleeve to protrude out of the plugging groove, and installing a gate valve on the upper part of the plugging sleeve; s3, injecting a water glass solution and a cement slurry solution along a gap between the plugging sleeve and the coring hole, and injecting a plugging agent into the plugging groove to plug the surfaces of the silica gel and the calcium silicate gel after the water glass solution and the cement slurry solution are glued into the silica gel and the calcium silicate gel; s4, inserting a grouting pipe into the plugging sleeve, injecting a water glass solution, a cement slurry solution and an expanding agent along the grouting pipe, and closing the gate valve after the grouting pipe is full; s5, opening the gate valve after the preset time and observing the core-pulling hole; if the core-pulling hole does not overflow or gush water, the plugging sleeve and the part of the grouting pipe protruding out of the plugging groove are cut off, and the plugging groove is filled with the plugging agent.

Description

Plugging method for core-pulling hole

Technical Field

The invention relates to the technical field of drilling holes, in particular to a plugging method of a cored hole.

Background

At present, a foundation pile foundation integrity detection method for a foundation pit is mature, such as a high-low strain detection method, a core-pulling detection method and the like, wherein a core-pulling hole needs to be blocked after a pile foundation or geology is detected by the core-pulling detection method, and the core-pulling hole is filled with cement slurry in a conventional operation. However, in a high-pressure-bearing water-rich sand layer or an area with shallow underground water level buried depth, core-pulling holes or geological drilling holes of pile foundations cannot be plugged or are poor in plugging quality and the like, so that after the foundation pit is excavated to the bottom of the pit, underground pressure-bearing water emerges from the core-pulling holes or the drilling holes, and the safety of the foundation pit is further influenced. Therefore, before the foundation pit is excavated, the plugging quality of the cored hole is ensured to be important.

In the prior art, when the core hole appears gushing water when the foundation ditch is excavated to the bottom of the pit, generally adopt biliquid thick liquid or grout to carry out the shutoff once more or adopt stake and cotton quilt to squeeze into to gush the water hole earlier, the trompil is gone into the shutoff of annotating biliquid thick liquid again, perhaps through a large amount of pump drainage groundwater methods in order to avoid the core hole to appear gushing water problem. However, because the gushing water has pressure bearing property, the double-liquid slurry is easy to wash away, the plugging efficiency is low, the construction period is long, the construction cost is increased, and the use is limited. If a large amount of underground water is pumped and drained, continuous pumping and drainage are needed to ensure that the underground water level is lower than the bottom elevation of the foundation pit, which creates conditions for basement bottom plate construction, but causes the peripheral underground water level to drop, affects the unevenness of peripheral building structures, roads or pipelines, causes settlement, and even affects the safety of the foundation pit.

Disclosure of Invention

In order to solve the technical problem that the construction safety of a foundation pit is easily influenced by the plugging quality problem of the cored hole, the invention provides a method for plugging the cored hole, which comprises the following steps:

s1, forming a plugging groove along the periphery of the opening of the core-pulling hole;

s2, inserting a plugging sleeve into the core-pulling hole, enabling the upper part of the plugging sleeve to protrude out of the plugging groove, and installing a gate valve on the upper part of the plugging sleeve;

s3, injecting a water glass solution and a cement slurry solution along a gap between the plugging sleeve and the coring hole, and injecting a plugging agent into the plugging groove to plug the surfaces of the silica gel and the calcium silicate gel after the water glass solution and the cement slurry solution are glued into the silica gel and the calcium silicate gel;

s4, inserting a grouting pipe into the plugging sleeve, injecting a water glass solution, a cement slurry solution and an expanding agent along the grouting pipe, and closing the gate valve after the grouting pipe is full;

s5, opening the gate valve after the preset time and observing the core-pulling hole; if the core pulling hole does not overflow or gush water, the plugging sleeve and the part of the grouting pipe protruding out of the plugging groove are cut off, and the plugging groove is filled with the plugging agent; and if the core-pulling hole has overflow or water gushing phenomenon, filling the plugging groove with a water glass solution and a cement paste solution.

Further, in the step S4, the water glass solution, the cement slurry solution and the expanding agent are injected along the grouting pipe at a grouting pressure not less than 0.6Mpa and a grout return time not less than 30S.

Further, in step S4, the volume ratio of the water glass to the pure water in the water glass solution is 1: 2-4, wherein the modulus of the water glass is 2.4-3.0;

the weight ratio of water in the cement slurry solution to cement is 0.5-0.6;

the volume ratio of the water glass solution to the cement slurry solution is 1: 1.

furthermore, the slip casting pipe is a double-core pipe, a plurality of grout outlet holes are formed in the lower end of the slip casting pipe, and the plurality of grout outlet holes are arranged in a quincunx shape.

Furthermore, the diameter size of the slurry outlet holes is 3-4 mm, and the distance between any two adjacent slurry outlet holes is 300 mm.

Further, the depth of the closed sleeve inserted into the coring hole in the step S2 is 1.5-1.7 m.

Further, the size of the gap between the plugging sleeve and the core-pulling hole in the step S2 is 5-6 mm.

Further, the thickness of the plugging agent in step S3 is 100-120 mm.

Further, the leakage stoppage agent is composed of portland cement clinker, natural alunite, gypsum, slag and fly ash, wherein the initial setting time is less than or equal to 5min, and the final setting time is less than or equal to 10 min.

Further, the predetermined time in step S5 is greater than 48 h.

Compared with the prior art, the core-pulling hole plugging method has the beneficial effects that:

according to the invention, the top of the core-pulling hole can be plugged by inserting the closed sleeve with the gate valve into the top opening of the core-pulling hole, so that the construction safety of the foundation pit is effectively ensured. The grouting pipe is used for grouting in the opening state of the gate valve, so that the grouting liquid is not influenced by the upward pressure of the pressure-bearing water, the closed sleeve can be fixed quickly, the valve can be closed quickly after the grouting pipe is full of grouting, the plugging quality of the grouting liquid to the core-pulling hole is ensured, and the purpose of quick plugging is realized. After grouting is finished, judging the plugging effect by observing the overflow or water burst condition of the cored hole so as to ensure the construction safety of the foundation pit at the back.

Drawings

Fig. 1 is a schematic structural diagram of the core-pulling hole plugging method of the present invention at step S2;

fig. 2 is a schematic structural diagram of the core-pulling hole plugging method of the present invention at step S4;

fig. 3 is a schematic structural diagram of the core-pulling hole plugging method of the present invention at step S5;

in the figure, 1, a core-pulling hole; 2. plugging the groove; 3. plugging the sleeve; 4. a gate valve; 5. a leakage stopping agent; 6. a grouting pipe; 7. a first slip casting; 8. and a second slip casting.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a method for plugging a core-pulling hole according to the present invention. The core-pulling hole plugging method specifically comprises the following steps:

s1, a plugging groove 2 is arranged along the periphery of the opening of the core-pulling hole 1.

The blocking groove may be a square groove, a circular groove, an irregular groove, or the like, which is not limited in the present invention. Further, the plugging groove of the present invention may preferably be a square groove, and the length and width dimensions of the plugging groove are 300mm and the depth dimension is 200mm, respectively. Typically, the core hole has a diameter dimension of 91mm, and the opening of the core hole is provided in the central region of the bottom of the plugging groove.

S2, the plugging sleeve 3 is inserted into the cored hole 1, the upper part of the plugging sleeve 3 is protruded outside the plugging groove 2, and the gate valve 4 is attached to the upper part of the plugging sleeve 3.

The plugging sleeve can be a PVC pipe body or a stainless steel pipe body. The plugging sleeve is inserted into the coring hole to a depth of 1.5-1.7 m, for example 1.5 m. The diameter of the plugging sleeve is designed according to the diameter of the core-pulling hole, so that a gap is formed between the outer side wall of the plugging sleeve and the inner side wall of the core-pulling hole, and the diameter of the gap is 5-6 mm, for example 5mm, namely the diameter of the plugging sleeve can be 81 mm.

Further, a gate valve can be arranged on the plugging sleeve 200mm away from the upper end face of the plugging sleeve for controlling the flow of the grouting liquid on the plugging sleeve.

S3, injecting a water glass solution and a cement slurry solution along the gap between the plugging sleeve 3 and the core-pulling hole 1, and injecting a plugging agent 5 into the plugging groove to plug the surfaces of the silica gel and the calcium silicate gel after the water glass solution and the cement slurry solution are glued into the silica gel and the calcium silicate gel.

The water glass solution and the cement slurry are used for preliminarily plugging the gap and fixing the position of the plugging sleeve in the core-pulling hole, and the debugging and solidifying time is less than 30 s. And then, the gap is further reinforced by adopting a plugging agent, so that enough anchoring force is formed between the plugging sleeve and the core-pulling hole, and the structural position of the plugging sleeve in the core-pulling hole is limited. The water glass solution and the cement slurry in step S3 are solidified to form the first grout 7.

The leakage stopping agent consists of silicate cement clinker, natural alunite, gypsum, slag and fly ash, wherein the initial setting time is less than or equal to 5min, and the final setting time is less than or equal to 10 min. Meanwhile, the thickness of the plugging agent can be 100-120 mm, such as 100 mm.

Further, the weight ratio of ammonia powder to water in the leak stoppage agent can be 1: 0.25. when the plugging device is operated, firstly, the plugging device is added into water, kneaded into small-size material pellets for plugging construction, then the small-size material pellets are plugged into the plugging grooves, and extruded by the wood rods to be firmly extruded to the periphery and the bottom of the plugging grooves by light smashing, so that the leakage can be stopped, and gaps between the sleeve and the core pulling hole can be plugged.

S4, inserting the grouting pipe 6 into the plugging casing pipe 3, injecting water glass solution, cement slurry solution and an expanding agent along the grouting pipe 6, and closing the gate valve 4 after the grouting pipe 6 is filled. It can be understood that the gate valve 4 is closed to prevent the water glass solution, the cement slurry solution and the expanding agent from flowing upwards along the plugging casing 3, so that the water glass solution, the cement slurry solution and the expanding agent are fully solidified in the plugging casing 3, that is, the gate valve 4 is used for bearing the pressure of the water glass solution, the cement slurry solution and the expanding agent, and the grouting solidification purpose is achieved in a plugging mode. The water glass solution, the cement slurry solution and the expanding agent in step S4 are solidified to form the second grout 8.

The grouting pipe is a double-core pipe, the lower end of the grouting pipe is provided with a plurality of grout outlet holes, and the plurality of grout outlet holes are arranged in a quincunx shape. The diameter size of the pulp outlet holes is 3-4 mm, and the distance between any two adjacent pulp outlet holes is 300 mm.

Furthermore, the grouting pressure of injecting the water glass solution, the cement slurry solution and the expanding agent along the grouting pipe is not less than 0.6Mpa, and the grout return time is not less than 30s, so that the soil and the miscellaneous slag at the bottom of the core-pulling hole are cleaned and discharged outside the hole, and the grouting filling of the hole is ensured.

Meanwhile, the volume ratio of the water glass to the pure water in the water glass solution is 1: 2-4, wherein the modulus of the water glass is 2.4-3.0; the weight ratio of water in the cement slurry solution to cement is 0.5-0.6; the volume ratio of the water glass solution to the cement slurry solution is 1: 1. in principle, the setting time of the water glass solution and the cement slurry solution is controlled within 30s, and is adjusted according to a field test and the size of the confined water gushing, and the setting time is adjusted to be shorter when the water gushing amount is larger.

S5, opening the gate valve 4 after a preset time and observing the core-pulling hole 1; if the core pulling hole 1 does not overflow or gush water, the plugging sleeve 3 and the grouting pipe 6 are cut off to protrude out of the plugging groove 2, and the plugging groove 2 is filled with plugging agent; if the core-pulling hole 1 overflows or gushes water, the plugging groove 2 is filled with water glass solution and cement slurry solution.

Wherein the preset time is more than 48h to ensure that the grouting pipe is plugged after the water glass solution and the cement slurry solution are fully solidified. And opening the gate valve after a preset time to check the grouting quality in the core pulling hole, and ensuring that the core pulling hole has no overflow or water burst phenomenon, cutting off the part of the plugging sleeve and the grouting pipe protruding out of the plugging groove, and filling the plugging groove with a plugging agent to plug the settling section in the core pulling hole, thereby completing the plugging work of the pile foundation core pulling hole, ensuring the good plugging quality and ensuring the construction safety of a subsequent foundation pit.

To sum up, the embodiment of the invention provides a method for plugging a core-pulling hole, which can plug the top of the core-pulling hole by inserting a closed sleeve with a gate valve into an opening at the top of the core-pulling hole, thereby effectively ensuring the construction safety of a foundation pit. The grouting pipe is used for grouting in the opening state of the gate valve, so that the grouting liquid is not influenced by the upward pressure of the pressure-bearing water, the plugging quality of the grouting liquid on the core-pulling hole is ensured, and the purpose of rapid plugging is realized. After grouting is finished, judging the plugging effect by observing the overflow or water burst condition of the cored hole so as to ensure the construction safety of the foundation pit at the back.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A core-pulling hole plugging method is characterized by comprising the following steps:

2. The method for plugging a coring hole according to claim 1, wherein the step S4 is performed by injecting the water glass solution, the cement slurry solution and the swelling agent along the grout pipe at a grouting pressure of not less than 0.6Mpa and a grout return time of not less than 30S.

3. The method for plugging a cored hole according to claim 1 or 2, wherein the volume ratio of water glass to pure water in the water glass solution in step S4 is 1: 2-4, wherein the modulus of the water glass is 2.4-3.0;

the weight ratio of water in the cement slurry solution to cement is 0.5-0.6;

4. the method for plugging a coring hole according to claim 1, wherein the grout tube is a double-core tube, and the lower end of the grout tube is provided with a plurality of grout outlet holes which are arranged in a quincunx shape.

5. The method for plugging a coring hole according to claim 4, wherein the diameter size of the grout outlet is 3-4 mm, and the distance between any two adjacent grout outlets is 300 mm.

6. The method for plugging a coring hole of claim 1, wherein the closure bushing is inserted into the coring hole to a depth of 1.5-1.7 m in step S2.

7. The method for plugging a coring hole according to claim 1, wherein the size of the gap between the plugging sleeve and the coring hole in step S2 is 5-6 mm.

8. The method for plugging a cored hole according to claim 1, wherein the thickness of the plugging agent in step S3 is 100-120 mm.

9. The method for plugging a cored hole according to claim 1 or 8, wherein the plugging agent is composed of portland cement clinker, natural alunite, gypsum, slag and fly ash, wherein the initial setting time is 5min or less, and the final setting time is 10min or less.

10. The method for plugging a coring hole according to claim 1, wherein the predetermined time in step S5 is greater than 48 hours.