CN111852484A

CN111852484A - Double-liquid grouting construction method

Info

Publication number: CN111852484A
Application number: CN202010607395.7A
Authority: CN
Inventors: 冯祖国; 李彦峰; 赵维志; 乔清源
Original assignee: Cccc Chongqing Investment Development Co Ltd
Current assignee: Henan Kaifu Industrial Co ltd
Priority date: 2020-06-29
Filing date: 2020-06-29
Publication date: 2020-10-30
Anticipated expiration: 2040-06-29
Also published as: CN111852484B

Abstract

The invention discloses a double-liquid grouting construction method which is characterized by comprising the following steps of: 1) installing a first grouting pipe and at least one second grouting pipe at a position to be grouted; 2) injecting grout into the first grouting pipe, stopping grouting when the grout overflows from the pipe orifice of the first grouting pipe, and injecting grout into the second grouting pipe after the grout is in a gel state; 3) and when the grouting flow in the second grouting pipe reaches 15-20L/min, continuing grouting for 5-10 min, and stopping grouting. The method can quickly reinforce the area with low soil body strength, the mechanical strength of the reinforced soil body is uniform, the excavated soil body can keep self-stability, and the construction safety requirement is met.

Description

Double-liquid grouting construction method

Technical Field

The invention relates to a grouting method, in particular to a double-liquid grouting construction method.

Background

As cities expand faster and traffic gets more and more busy, some cities begin to build rail traffic to relieve the traffic pressure of congestion.

In the construction of track traffic, often can use the shield structure machine to excavate, improve work efficiency. And in some specific areas, for example, steel strands which are embedded during anchor cable construction exist in strata in the area, or areas with low mechanical strength of soil body cannot be directly excavated, the areas with low mechanical strength of the soil body are usually reinforced by adopting a grouting mode, the traditional grouting mode is to directly pour cement paste into the soil for reinforcement, the soil body reinforced by the method has different strengths, and some local strengths are large and some local strengths are small. The gel time of the single-slurry is generally 8 hours, and the gel time of the partial double-slurry is 30 minutes, so that the construction period is difficult to accelerate for a scheme with an urgent construction task.

Therefore, the technical personnel in the field are dedicated to developing a double-liquid grouting construction method, the method can quickly reinforce the area with low soil body strength, the mechanical strength of the reinforced soil body is uniform, the excavated soil body can keep self-stability, and the construction safety requirement is met.

Disclosure of Invention

In view of the above defects in the prior art, the technical problem to be solved by the present invention is to provide a two-fluid grouting construction method, which can not only quickly reinforce a region with low soil strength, but also has uniform mechanical strength of the reinforced soil, and the excavated soil can maintain self-stability, thereby meeting the construction safety requirements.

In order to achieve the purpose, the invention provides a double-liquid grouting construction method which is characterized by comprising the following steps of:

1) installing a first grouting pipe and at least one second grouting pipe at a position to be grouted;

2) injecting grout into the first grouting pipe, stopping grouting when the grout overflows from the pipe orifice of the first grouting pipe, and injecting grout into the second grouting pipe after the grout is in a gel state;

3) and when the grouting flow in the second grouting pipe reaches 15-20L/min, continuing grouting for 5-10 min, and stopping grouting. Grouting above the grouting holes, so that soil can be conveniently pressed in the subsequent grouting process, the soil body is further reinforced, and the mechanical strength of the soil body is uniform.

Further, the slurry is mixed slurry of cement slurry and water glass. The addition of water glass in the slurry is not only beneficial to improving the strength, but also convenient to control the setting time of the slurry.

Furthermore, a grout stop plug is arranged at a position 6-8 m below the ground along the direction of the second grouting pipe, and a grout outlet of the first grouting pipe (1) is arranged above the grout stop plug. And a grout stopping plug is arranged in the grouting hole, so that grout injected firstly can be blocked, and a closed chamber is formed.

Furthermore, the grout outlets of the second grouting pipes are arranged below the grout stop plugs, and the length difference of two adjacent second grouting pipes is 3-5 m. The plurality of second grouting pipes are not only beneficial to simultaneous grouting, but also beneficial to observing the grouting condition during single grouting.

Furthermore, the second grouting pipes are sequentially arranged according to the length sequence. The second grouting pipes are arranged in the length sequence, so that grouting and observation are facilitated, no grouting blind area is left, and the uniformity of grouting reinforcement is ensured.

Further, the weight ratio of water to cement in the cement paste is 0.4-1: 1-1: 1.2, the weight mixing amount of the water glass is 10-18% of the weight of the slurry. The content of the water glass and the cement is adjusted at any time according to the construction area and the construction progress so as to achieve the best grouting reinforcement effect.

Furthermore, a fixing device is further arranged outside the first grouting pipe and the second grouting pipe, and reinforcing parts are arranged between the fixing device and the first grouting pipe and between the fixing device and the second grouting pipe respectively. Fixing device and reinforcement are favorable to stabilizing each slip casting pipe, prevent that the slip casting in-process from appearing great rocking, influence the slip casting effect.

Further, the diameters of the first grouting pipe and the second grouting pipe are both 25 mm.

Further, in step 2) and step 3):

when the length of the grouting pipe is less than 7m, the grouting pressure is 0.6 Mpa-1 Mpa;

when the length of the grouting pipe is 7-9 m, the grouting pressure is 1.0-1.5 Mpa;

when the length of the grouting pipe is 9-13 m, the grouting pressure is 1.5-2.0 Mpa;

when the length of the grouting pipe is 13-17 m, the grouting pressure is 2.0-2.5 Mpa;

when the length of the grouting pipe is more than 17m, the grouting pressure is 2.5 Mpa. In the grouting process, the grouting pressure is adjusted according to the length and the diameter of the grouting pipe, so that the grouting effect is also achieved in the grouting process.

Further, in step 2) and step 3):

when the flow rate of the slurry is more than 30L/min, the gelling time of the slurry is 1-2 min;

when the flow rate of the slurry is 20L-30L/min, the gelling time of the slurry is 3 min-4 min;

When the flow rate of the slurry is less than 20L/min, the gelling time of the slurry is 5-6 min. Controlling the gel time is advantageous for controlling the slurry diffusion radius.

The invention has the beneficial effects that: the grouting liquid adopts a mixed solution of cement and water glass, and grouting parameters are dynamically adjusted according to hydrogeological conditions, so that the gel time is conveniently controlled; solidifying the soil body by adopting modes of infiltration, compaction, splitting, forming and grouting and the like without leaving a grouting blind area; the area with low soil body strength is quickly reinforced, the mechanical strength of the reinforced soil body is uniform, the excavated soil body can keep self-stability, and the construction safety requirement is met.

Drawings

FIG. 1 is a schematic flow chart of an embodiment of the present invention.

Fig. 2 is a schematic top view of a grouting device according to an embodiment of the present invention.

FIG. 3 is a schematic side view of a grouting device according to an embodiment of the invention.

FIG. 4 is a schematic view of a slip casting arrangement according to an embodiment of the present invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and examples, wherein the terms "upper", "lower", "left", "right", "inner", "outer", and the like, as used herein, refer to an orientation or positional relationship indicated in the drawings, which is for convenience and simplicity of description, and does not indicate or imply that the referenced devices or components must be in a particular orientation, constructed and operated in a particular manner, and thus should not be construed as limiting the present invention. The terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that the terms "mounted," "connected," and "in communication with" are to be construed broadly unless otherwise specifically stated or limited. The raw materials, such as cement, water glass and the like, involved in the invention are all obtained from the market, and the machines involved in the invention, such as a mixer and a double-liquid grouting machine, are all common machines in the building engineering. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in fig. 1 to 4:

example 1

The water glass stock solution adopts 40 DEG Be, is mixed with water and diluted to 20 DEG Be, and the mark of cement is P.O42.5. The weight ratio of water to cement is 0.4:1, cement and water are mixed in the stirring barrel and then transferred to the slurry storage barrel for temporary storage, during grouting, the opening degree of a valve in the conveying pipe is adjusted, so that the weight mixing amount of water glass is 10% of the weight of the slurry, and a slurry stop plug 3 is arranged 6m below the ground along the direction of the second grouting pipe 2. The length of first slip casting pipe 1 is 5.5m, and there are 3 second

slip casting pipes

2, and 3 second

slip casting pipes

2 and 1 first slip casting pipe 1 form the square, and the length of 3 second slip casting pipes is 8m, 11m, 14m respectively.

Mixing by a mixer, injecting grout into the first grouting pipe 1, adjusting the mixing ratio of the grout and the water glass to ensure that the flow rate of the grout is 18L/min, stopping injecting when grout overflows from a grouting hole of the first grouting pipe 1, waiting for grout to gel for 5min, and injecting the grout into the second grouting pipe 2 after the grout gels.

And simultaneously injecting grout into the 3 second grouting pipes 2, wherein the grouting pressures are respectively 1Mpa, 1Mpa and 1.5Mp, and when the grouting flow is 20L/min, the grouting is stopped after continuing to inject for 5 min.

Example 2

The water glass stock solution adopts 40 DEG Be, is mixed with water and diluted to 25 DEG Be, and the mark of cement is P.O42.5. The weight ratio of water to cement is 0.6:1, cement and water are mixed in the stirring barrel and then transferred to the slurry storage barrel for temporary storage, during grouting, the opening degree of a valve in the conveying pipe is adjusted, so that the weight mixing amount of water glass is 13% of the weight of the slurry, and a slurry stop plug 3 is arranged 7m below the ground along the direction of the second grouting pipe 2. The length of first slip casting pipe 1 is 6m, and second slip casting pipe 2 has 2, and 2 second

slip casting pipes

2 and 1 first slip casting pipe 1 form regular triangle, and the length of 2 second slip casting pipes is 13m, 17m respectively.

And mixing by a mixer, injecting the grout into the first grouting pipe 1, wherein the grouting pressure is 1Mpa, the grout flow is 25L/min, the injection is stopped when the grout overflows from a grouting hole of the first grouting pipe 1, the grout is kept for gelling for 7min, and then the grout is injected into the second grouting pipe 2 after gelling.

And injecting grout into the 2 second grouting pipes 2 simultaneously, wherein the grouting pressures are respectively 2Mpa and 2.2Mp, and when the grouting flow is 18L/min, the grouting is stopped after continuing to inject for 6 min.

Example 3

The water glass stock solution adopts 40 DEG Be, is mixed with water and diluted to 30 DEG Be, and the mark of cement is P.O42.5. The weight ratio of water to cement is 0.8:1, cement and water are mixed in the stirring barrel and then transferred to the slurry storage barrel for temporary storage, during grouting, the opening degree of a valve in the conveying pipe is adjusted, so that the weight mixing amount of water glass is 17% of the weight of the slurry, and a slurry stop plug 3 is arranged 7.5m below the ground along the direction of the second grouting pipe 2. The length of first slip casting pipe 1 is 7m, and there are 3 second

slip casting pipes

2, and 3 second

slip casting pipes

2 and 1 first slip casting pipe 1 form the square, and the length of 3 second slip casting pipes is 9m, 13m, 17m respectively.

And mixing by a mixer, injecting grout into the first grouting pipe 1, adjusting the mixing ratio of the grout and the water glass to ensure that the flow rate of the grout is 30L/min, stopping injecting when grout overflows from a grouting hole of the first grouting pipe 1, waiting for grout to gel, wherein the grout gelling time is 4min, and controlling the gelling time to be 45 seconds for a part of areas needing quick gelling. After the gel, the slurry is injected into the second slurry injection pipe 2.

And simultaneously injecting grout into the 3 second grouting pipes 2, wherein the grouting pressures are respectively 2.2Mpa, 2.2Mpa and 2.5Mp, and when the grouting flow is 17L/min, the grouting is stopped after continuing to inject for 8 min.

Example 4

The water glass stock solution adopts 40 DEG Be, is mixed with water and diluted to 35 DEG Be, and the mark of cement is P.O42.5. The weight ratio of water to cement is 1:1.2, cement and water are mixed in the stirring barrel and then transferred to the slurry storage barrel for temporary storage, during grouting, the opening degree of a valve in the conveying pipe is adjusted, so that the weight mixing amount of water glass is 18% of the weight of the slurry, and a slurry stop plug 3 is arranged 8m below the ground along the direction of the second grouting pipe 2. The length of first slip casting pipe 1 is 7.5m, and there are 3 second

slip casting pipes

2, and 3 second

slip casting pipes

2 and 1 first slip casting pipe 1 form the square, and the length of 3 second slip casting pipes is 9m, 14m, 18m respectively.

And mixing by a mixer, injecting the grout into the first grouting pipe 1, wherein the grouting pressure is 1Mpa, the grout flow is 32L/min, the injection is stopped when the grout overflows from a grouting hole of the first grouting pipe 1, the grout is kept for gelling for 1min, and then the grout is injected into the second grouting pipe 2 after gelling.

And (3) injecting grout into the 3 second grouting pipes 2 simultaneously, wherein the grouting pressure is 2.5Mp, and when the grouting flow is 15L/min, the grouting is stopped after continuing to inject for 10 min.

In embodiments 1 to 4, before grouting, a first grouting pipe 1 and at least a second grouting pipe 2 are installed at a position to be grouted, the diameters of the first grouting pipe 1 and the second grouting pipe 2 are both 25mm, a fixing device 4 is further installed outside the first grouting pipe 1 and the second grouting pipe 2, the fixing device 4 is usually a round steel plate, holes are formed in the round steel plate, grouting pipes are installed in the holes, a reinforcing part 5 is respectively arranged between the fixing device 4 and the first grouting pipe 1 and the second grouting pipe 2, the reinforcing part 5 is connected with the grouting pipes and the fixing device in a welding mode, the reinforcing part 5 is used for further fixing the grouting pipes, the situation that the grouting pipes shake too much in the grouting process to influence the grouting effect is avoided, a double-liquid grouting machine is adopted in the grouting process, and the double-liquid grouting machine is provided with a pressure gauge a1 and a three-way pressure reducing valve for controlling grouting pressure. A bypass valve is arranged in front of the mixer and used for controlling the grouting flow, a connector A2 is further arranged between the grouting pipe A3 and the outlet pipe of the mixer so as to facilitate connection between the grouting pipe A3 and the outlet pipe of the mixer in order to facilitate connection between the grouting pipe A3 and the outlet pipe of the mixer.

And (3) carrying out quality detection after the strength of the grouting consolidation body reaches 75% or 7 days after grouting is finished, wherein the number of the inspection points is 1% of the number of the construction holes and is not less than 3. The method is characterized in that the core pulling method of the geological drilling machine in the technical specification of cement-water glass double-liquid grouting for building engineering is used for checking, the integrity of pore forming is detected, the pore forming rate is greater than 95% in examples 1 to 4, compared with the prior art, the grouting blind area is less than 5%, and the grouting blind area is greatly reduced.

And (3) performing a grouting test on the cored hole, finding that the sine value of the tangent of a P-Q-T curve is greater than that of the tangent of the curve during normal construction, after 5-10 min of grouting, the P, Q value reaches the design final pressure value, the compactness of the soil body after grouting is good, and performing a sealed water injection pressure test on the cored hole, wherein in examples 1-4, the water injection pressure exceeds 1.0Mpa, and the strength of the soil body after grouting is uniform, which indicates that the grouting blind area is less.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims

1. A double-liquid grouting construction method is characterized by comprising the following steps:

1) installing a first grouting pipe (1) and at least one second grouting pipe (2) at a position to be grouted;

2) injecting grout into the first grouting pipe (1), stopping grouting when the grout overflows from the pipe orifice of the first grouting pipe (1), and injecting grout into the second grouting pipe (2) after the grout is in a gel state;

3) and when the grouting flow rate in the second grouting pipe (2) reaches 15-20L/min, continuing grouting for 5-10 min, and stopping grouting.

2. The double-liquid grouting construction method according to claim 1, characterized in that: the slurry is mixed slurry of cement slurry and water glass.

3. The double-liquid grouting construction method according to claim 1, characterized in that: a grout stop plug (3) is arranged at a position 6-8 m below the ground along the direction of the second grouting pipe (2), and a grout outlet of the first grouting pipe (1) is arranged above the grout stop plug (3).

4. The double-liquid grouting construction method according to claim 3, characterized in that: the grout outlets of the second grouting pipes (2) are arranged below the grout stopping plugs (3), and the length difference of two adjacent second grouting pipes (2) is 3-5 m.

5. The double-liquid grouting construction method according to claim 1, characterized in that: the second grouting pipes (2) are sequentially arranged according to the length sequence.

6. The double-liquid grouting construction method according to claim 2, characterized in that: the weight ratio of water to cement in the cement paste is 0.4-1: 1-1: 1.2, the weight mixing amount of the water glass is 10-18% of the weight of the slurry.

7. The double-liquid grouting construction method according to claim 1, characterized in that: the first grouting pipe (1) and the second grouting pipe (2) are also provided with fixing devices (4), and reinforcing parts (5) are arranged between the fixing devices (4) and the first grouting pipe (1) and the second grouting pipe (2) respectively.

8. The double-liquid grouting construction method according to claim 1, characterized in that: the diameters of the first grouting pipe (1) and the second grouting pipe (2) are both 25 mm.

9. The two-fluid grouting construction method according to claim 1, wherein in step 2) and step 3):

when the length of the grouting pipe is more than 17m, the grouting pressure is 2.5 Mpa.

10. The two-fluid grouting construction method according to claim 2, wherein in step 2) and step 3):

when the flow rate of the slurry is less than 20L/min, the gelling time of the slurry is 5-6 min.