CN112176781A

CN112176781A - Method for controlling subgrade settlement of high-speed rail operation

Info

Publication number: CN112176781A
Application number: CN201910605152.7A
Authority: CN
Inventors: 王立伟; 谢良生; 王博; 苗围中; 马艳青; 王云飞
Original assignee: Beijing Huatie Times Construction Development Co ltd
Current assignee: Beijing Huatie Times Construction Development Co ltd
Priority date: 2019-07-05
Filing date: 2019-07-05
Publication date: 2021-01-05

Abstract

The invention provides a method for controlling subgrade settlement of an operating high-speed rail, which comprises the following steps of firstly, arranging grouting holes on the subgrade of the high-speed rail; and secondly, drilling holes at the positions of the arranged grouting holes to form the grouting holes, and grouting into the grouting holes, wherein the change of track parameters is monitored in the grouting process, the method is constructed aiming at the existing railway to control the sinking of the roadbed operating high-speed rails, meanwhile, the method can be constructed in real time on site, the damage to the roadbed is small, and the construction cost is low.

Description

Method for controlling subgrade settlement of high-speed rail operation

Technical Field

The invention relates to the technical field of existing railway roadbed maintenance engineering, in particular to a method for controlling roadbed subsidence of an operating high-speed rail.

Background

In recent years, with the rapid development of high-speed railways, large-scale high-speed railways are built in China, and great convenience is brought to people for traveling. However, in the operation process of the high-speed railway, the roadbed of the high-speed railway has some disease problems. For example, the individual roadbed filling (particularly the high filling B, C type filling section) causes unsmooth track geometric dimension due to settlement deformation, and a part of serious sections (the settlement amount is more than 20mm, and the type A diseases are reached) exceed the adjusting range of a track connecting system, so that the train is influenced to operate at the specified speed.

The subgrade sinking disease treatment is more, for example, masonry, retaining wall, ballast bed lifting and the like are arranged. However, the scheme has the defects of large damage degree to the roadbed, high construction cost, large construction difficulty and the like.

Therefore, a method for controlling the subgrade settlement of the high-speed rail operation, which has the advantages of small damage degree to the road basic body, low engineering cost and simple and convenient construction, needs to be designed.

Disclosure of Invention

Aiming at part or all of the technical problems in the prior art, the invention provides a method for remedying the subgrade settlement of the high-speed rail. The method aims at the construction of the existing railway to rectify the subgrade sinking of the operating high-speed rail. Meanwhile, the method can be used for construction on site in real time, vehicles can run during construction, damage to the roadbed is small, and construction cost is low. In addition, the method extrudes water and gas in the soil body by grouting slurry in the modes of filling, permeating, compacting, splitting and the like, fills the original gaps or cracks in the soil body, bonds loose soil particles together and improves the compactness of the soil body. In the chemical reaction process of the slurry, certain chemical agents and elements in rock and soil are subjected to ion exchange to form new substances, the cohesive force of soil is increased, the aims of reinforcing (improving the mechanical strength and the deformation modulus of the rock and soil mass), blocking (filling pores, cracks and blocking flowing water), preventing seepage (reducing permeability and reducing seepage flow) and the like are fulfilled, the soil mass is cemented into a whole, and a combination with a new structure, high strength, good waterproof performance and good chemical performance is formed, so that the settlement resistance of the roadbed is greatly improved, and the roadbed is prevented from further sinking.

According to the invention, the method for remedying the subgrade settlement of the operating high-speed rail comprises the following steps:

step one, arranging grouting holes on a high-speed rail roadbed,

and secondly, drilling holes at the distributed grouting holes to form grouting holes, and grouting into the grouting holes, wherein track parameter changes are monitored in the grouting process.

In one embodiment, the grouting holes oppositely extend into the road basic body or the foundation from the slope lines of the roadbed on two sides in the transverse section, the distance between the adjacent grouting holes is 0.5-1.0m, and the grouting holes on the same transverse section are called a grouting hole group,

in the longitudinal direction, the adjacent grouting hole groups are arranged at intervals of 1.8-2.2m and distributed in a quincunx shape.

In one embodiment, in the transverse cross section, the tail end of each grouting hole extends downwards relative to the starting end, and the included angle formed by different grouting holes and the horizontal direction is gradually increased from top to bottom.

In one embodiment, in step two, after the drilling is completed, a grouting pipe is put into the hole, and a grout outlet is arranged on the grouting pipe to perform backward sectional grouting.

In one embodiment, the first discharge port is located 0.5-1m from the end of the injection hole, and the adjacent discharge ports are spaced 0.5-1.5m apart.

In one embodiment, the grouting pressure when grouting the grouting hole at the position is 0.5-1MPa if the position of the grout outlet is under the subgrade bed, and the grouting pressure when grouting the grouting hole at the position is 0.2-0.3MPa if the position of the grout outlet is in the subgrade bed.

In one embodiment, after the grout tube is lowered into the borehole, the space between the grout tube and the borehole is filled with casing cement.

In one embodiment, after construction enters a field, a total station is used for acquiring the geometric dimensions of each monitoring point and each line to serve as original data, the geometric dimensions of each monitoring point and each line are measured in real time in the construction process, and the rail surface elevation is adjusted when the elevation deformation of the monitoring result relative to the original data reaches a limit value.

In one embodiment, during monitoring, adjacent monitoring points are located at the ends of sleepers on different sides, with one sleeper spaced between adjacent monitoring points.

In one embodiment, in steps one and two, the train is operated at a speed of no greater than 60 Km/H.

Compared with the prior art, the method has the advantages that the grouting holes are distributed on the roadbed, and the grouting is carried out in the grouting holes formed after drilling, so that the construction can be carried out on site in real time. Meanwhile, the mode has small damage degree to the roadbed, low construction cost and easier construction. In addition, the method extrudes water and gas in the soil body by grouting slurry in the modes of filling, permeating, compacting, splitting and the like, fills the original gaps or cracks in the soil body, bonds loose soil particles together and improves the compactness of the soil body. In the chemical reaction process of the slurry, certain chemical agents and elements in rock and soil are subjected to ion exchange to form new substances, the cohesive force of soil is increased, the aims of reinforcing (improving the mechanical strength and the deformation modulus of the rock and soil mass), blocking (filling pores, cracks and blocking flowing water), preventing seepage (reducing permeability and reducing seepage flow) and the like are fulfilled, the soil mass is cemented into a whole, and a combination with a new structure, high strength, good waterproof performance and good chemical performance is formed, so that the settlement resistance of the roadbed is greatly improved, and the roadbed is prevented from further settling.

Drawings

Preferred embodiments of the present invention will be described in detail below with reference to the attached drawing figures, wherein:

FIG. 1 shows a schematic diagram of a grout hole placement in cross-section according to one embodiment of the present invention;

FIG. 2 shows a schematic diagram of the placement of grout holes longitudinally in accordance with one embodiment of the present invention;

FIG. 3 shows a schematic layout of detection points on a track according to an embodiment of the invention;

fig. 4 shows a schematic illustration of grouting according to an embodiment of the invention.

In the drawings, like parts are provided with like reference numerals. The figures are not drawn to scale.

Detailed Description

The invention will be further explained with reference to the drawings.

The application provides a method for remedying subgrade settlement of an operating high-speed rail.

Firstly, grouting holes are arranged on a high-speed rail roadbed. Then, a hole is drilled at the arranged grouting hole position to form a grouting hole, and grouting is performed into the grouting hole. Wherein track parameter changes are monitored during grouting.

Therefore, the method is used for construction of existing railways to control subgrade sinking of the operating high-speed rail. Meanwhile, the method can be used for construction on site in real time, vehicles can run during construction, damage to the roadbed is small, construction cost is low, and construction is very easy. In addition, the method extrudes water and gas in the soil body by grouting slurry in the modes of filling, permeating, compacting, splitting and the like, fills the original gaps or cracks in the soil body, bonds loose soil particles together and improves the compactness of the soil body. In the chemical reaction process of the slurry, certain chemical agents and elements in rock and soil are subjected to ion exchange to form new substances, the cohesive force of soil is increased, the aims of reinforcing (improving the mechanical strength and the deformation modulus of the rock and soil mass), blocking (filling pores, cracks and blocking flowing water), preventing seepage (reducing permeability and reducing seepage flow) and the like are fulfilled, the soil mass is cemented into a whole, and a combination with a new structure, high strength, good waterproof performance and good chemical performance is formed, so that the settlement resistance of the roadbed is greatly improved, and the roadbed is prevented from further settling.

Specifically, the grouting hole site lofting is performed first. According to the initial mileage for disease control provided by design, the total station is used for setting an initial line and a first row of grouting hole longitudinal and transverse line piles on the side slopes on two sides of the roadbed by using the data of the existing CP III piles on the line, finally, each hole site is determined on the side slopes of the roadbed according to the designed hole pitch and hole site graphs according to the first row of longitudinal and transverse lines, and the wood sheet piles marked with the hole numbers are used for positioning

For example, in one embodiment, as shown in fig. 1, in a transverse cross section, grouting holes (indicated by the drawing number 1) oppositely extend from the roadbed slope lines (indicated by the drawing number 2) on both sides into the roadbed body (indicated by the drawing number 3) or the foundation (indicated by the drawing number 4). The distance between the upper ports (starting ends) of the adjacent grouting holes on the same side is 0.5-1.0m, such as 0.7 m. The grouting holes on the same transverse section are called grouting hole groups. In the longitudinal direction, as shown in fig. 2, the adjacent grouting hole groups are arranged at intervals of 1.8-2.2m and distributed in a quincunx shape. The distributed grouting holes are compact and optimized in structure and can help to improve the sinking problem of the roadbed. It should be noted that the subgrade slope line may be an outer side wall line of the subgrade body, or an upper surface wall line of the foundation connected with the outer wall line.

Preferably, the end of each grouting hole extends downwards relative to the starting end, and the included angle formed by different grouting holes and the horizontal direction is gradually increased in the top-to-bottom direction. That is, each of the injection holes is an inclined hole extending downward. The arrangement mode enables the grouting holes to be more uniformly distributed in the roadbed on the cross section, and ensures that the grout is uniformly diffused. In a specific construction case in fig. 1, the angle between the extension direction of the grouting hole and the horizontal direction is shown.

And drilling according to the arranged grouting hole directions. For example, the angle positioner or the self-contained angle instrument of the drilling machine can be used for obliquely positioning the drill rod of the drilling machine and drilling, and the alloy drill bit with the diameter of 110mm can be used for drilling by adding the protective pipe. And (3) withdrawing the drill rod after the designed depth is reached, wherein the drilling machine is required to be firmly arranged, the drilling process cannot deviate, the hole direction needs to be on the cross section of the roadbed, the hole channel is straight, and after the drilling is finished, residual soil particles in the hole are cleaned by high-pressure air so as to ensure that the grouting channel is smooth. And (4) checking the hole after the hole drilling is finished, transferring the drilling machine to the next hole after the hole drilling is qualified, and covering the finished grouting hole.

As shown in fig. 4, a grout pipe (indicated by reference numeral 6 in fig. 4) is run into the drilled hole to pour grout into the formation through the grout pipe. The grouting pipe is a pressed component and is left in the grouting pipe after grouting and plays a role of a 'rib'. Therefore, the arrangement increases the strength of the soil body, and can effectively increase the compactness of the soil body, so that the soil body is bonded with the grouting liquid to solve the problem of the sinking of the roadbed of the high-speed rail.

After the grouting pipe is put in, casing material (indicated by reference numeral 7 in fig. 4) needs to be poured to fill the annulus between the grouting pipe and the drilled hole, so as to ensure the position of the grouting pipe and further ensure the effect of subsequent pouring construction. For example, the mass ratio of the shell material, water and soil in the shell material is 1.6: 1: 1.

preferably, a slurry discharge port (indicated by reference numeral 61 in fig. 4) is provided on the slurry injection pipe for performing the backward stage slurry injection. The sectional retreating type grouting is beneficial to really realizing repeated fine grouting in localized area, quantitative amount and constant pressure, and has very important practical significance for reinforcing the railway roadbed. For example, the first discharge port (discharge port at the end) is located at a distance of 0.5 to 1m from the end of the injection hole. And the distance between the adjacent slurry discharge ports is 0.5-1.5 m. It should be noted that the slurry outlets may be arranged in a group, for example, the first slurry outlet is arranged in a plurality of groups, and is distributed on the outer wall of the slurry injecting pipe in a quincunx shape. That is to say, a plurality of slurry discharging openings for simultaneously grouting are a group so as to meet the aim of uniformly distributing slurry to the stratum. When the slurry discharge ports are a group, the distance between adjacent slurry discharge ports is the distance between the group of slurry discharge ports and the group of slurry discharge ports. The concrete grouting mode can ensure the effective diffusion of the grout, thereby achieving the purposes of reinforcement and full plugging. Of course, the position of the discharge port of the grouting hole may be selected according to specific construction conditions and considering the versatility of the grouting pipe, etc.

In the grouting process, different grouting pressures can be adopted for grouting according to the position of the grout outlet. For example, when the discharge port is located under the roadbed, the grouting pressure at the time of grouting the grouting hole is 0.5 to 1MPa, and when the discharge port is located in the roadbed, the grouting pressure at the time of grouting the grouting hole is 0.2 to 0.3 MPa. That is, the roadbed below the foundation bed can adopt higher pressure grouting, and the diffusion radius of grout is larger. And lower-pressure grouting is adopted in the foundation bed, so that secondary diseases such as arching deformation of the upper structure and the like caused by grouting are prevented to the maximum extent. The arrangement mode can ensure effective diffusion of grouting liquid, thereby ensuring good transformation effect. When each slurry outlet is grouted, the grouted slurry is firstly diluted and then thickened. For example, if cement grout is injected, the water cement ratio of the cement grout is adjusted during the grouting process, for example, the water cement ratio of the cement grout is 1:1 in the first 5min of the injection process, and the water cement ratio of the cement grout fed thereafter is 0.8: 1. When grouting is carried out on each grout outlet, the pressure and the discharge capacity of grouting are increased from small to large. For example, if cement slurry is injected, the pressure of the cement slurry is 0.5MPa for the first 5min, and then the pressure of the cement slurry fed is increased to 0.8 MPa.

During the staged grouting, the grouting can be stopped in one of the following situations. Firstly, the pulp suction per minute is less than or equal to 1.0-1.5L/min; second, single stage grouting for over 15 min. During grouting, if slurry leakage occurs at the opening or around the grouting hole, grouting is stopped immediately, and a slurry leakage point is blocked. And after plugging, continuing grouting, and simultaneously reducing the pressure or thickening the slurry. Grouting can be finished when the above measures are still adopted for grouting, but a compensation measure is implemented on the adjacent grouting hole. Of course, during the on-site construction process, it can also be determined empirically whether grouting needs to be stopped, for example, if a predetermined pressure is exceeded or the pressure is stabilized and then suddenly drops.

During the grouting process, a sleeve valve tube (indicated by figure number 8 in fig. 4) can be used. As shown in fig. 4, the first discharge port grouting will be described as an example. The sleeve valve pipe is provided with an injection port (shown by a figure number 81 in figure 4) on the wall thereof to communicate with the first grout outlet, and bowl-shaped grout stoppers (shown by a figure number 82 in figure 4) on the wall of the sleeve valve pipe at the upper end and the lower end of the injection port to seal the annular space between the sleeve valve pipe and the grout pipe and prevent the grout from spreading to other grout outlets. Meanwhile, a one-way rubber plug (indicated by a reference numeral 83 in fig. 4) is arranged on the outer wall of the injection opening, and the one-way rubber plug can be pushed away by pressure during grouting. If the pressure outside the sleeve valve tube is larger than the pressure inside the sleeve valve tube, the one-way rubber plug is closed. In the process of injecting grout through the inner cavity of the sleeve valve tube (in the direction shown by an arrow in fig. 4), the grout can be separated from the one-way rubber plug after passing through the injection port and the first grout outlet and can be diffused into the stratum soil body. After the first grout outlet is grouted, the sleeve valve pipe can be lifted up to enable the filling port to be communicated with the corresponding grout outlet, and the sleeve valve pipe is used for grouting other grout outlets. By adopting the method to carry out grouting, the gradual position, grouting amount and range can be effectively controlled; grouting can be carried out at any section as required; in the grouting process, the control is easy, grout bleeding and grout string can be effectively prevented or avoided, and a grouting blind area is not easy to generate; in the operation process, the grouting and the drilling can be separated, so that the allocation of operating personnel and working procedures is facilitated, and the labor is reduced.

In the construction process, the track parameters need to be detected, and the obtained parameters are compared to obtain the track parameter change, so as to ensure the smooth construction. For example, a total station is used for monitoring, and after the construction enters the field, the geometric dimensions of each monitoring point (indicated by the reference number 5 in fig. 3) and the line are acquired as original data. And in the construction process, the geometric dimensions of each monitoring point and the line are measured in real time. For example, every two hours or so. And adjusting the elevation of the rail surface when the elevation deformation of the monitoring result relative to the original data reaches a limit value. For example, the limit value may be 5 mm. Preferably, as shown in fig. 3, adjacent monitoring points are disposed at the ends of the sleepers on different sides, with one sleeper spaced between adjacent monitoring points.

In the grouting process, different grout can be poured according to different areas and different requirements. For example, in consideration of economy, a cement slurry may be poured, for example, a cement single slurry having a water-cement ratio of 0.8:1 to 1:1, and a cement material of sulphoaluminate or ordinary portland cement. In areas with abundant rainwater, cement-water glass double liquid can be adopted for grouting. For example, a cement to water glass double cement ratio of 0.8: 1-1: 1, the mixing volume ratio of cement to water glass is 1: 0.1-1: 1, the concentration of the water glass is 30-43 Be, and the modulus is 2.4-3.4. Wherein the water for mixing the slurry is drinking water or the water quality is 5-PH 9. In the construction process, a pulping machine with the capacity of about 1000L and the rotating speed of more than 200 r/min can be selected for pulping. And stirring the slurry according to the matching parameters, wherein the stirring time is not less than 2 minutes and not more than 6 minutes. In addition, the slurry outlet of the pulping machine is provided with 100 curtains of filter screens for filtering so as to ensure the quality of the grouting liquid.

In the construction process, the running is not interrupted, and the operation can also be carried out by using a maintenance skylight for stopping the high-speed rail at night, but the running speed of the train during grouting is required to be not more than 60 Km/H.

The above is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily make changes or variations within the technical scope of the present invention disclosed, and such changes or variations should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method of remediating subgrade settlement in operating high-speed rail, comprising:

step one, arranging grouting holes on a high-speed rail roadbed,

2. The method of claim 1, wherein in the first step, the grouting holes extend oppositely into the roadbed body or the foundation from the roadbed slope lines on two sides in the transverse section, the distance between the adjacent grouting holes is 0.5-1.0m, and the grouting holes on the same transverse section are called a grouting hole group,

3. The method of claim 2, wherein in a transverse cross-section, the end of each grouting hole extends downward relative to the starting end, and the included angle of different grouting holes with the horizontal direction becomes gradually larger in the top-to-bottom direction.

4. The method according to any one of claims 1 to 3, wherein in step two, a grouting pipe is lowered therein after completion of drilling, and a discharge port is provided on the grouting pipe for retreat-staged grouting.

5. The method of claim 4, wherein the first discharge port is located 0.5-1m from the end of the injection hole and adjacent discharge ports are spaced 0.5-1.5m apart.

6. The method according to claim 5, wherein the grouting pressure at the time of grouting the grouting hole at the position is 0.5 to 1MPa if the discharge port is positioned under the roadbed, and the grouting pressure at the time of grouting the grouting hole at the position is 0.2 to 0.3MPa if the discharge port is positioned in the roadbed.

7. Method according to any of claims 4 to 6, characterized in that after the injection tube has been lowered into the borehole, the space between the injection tube and the borehole is filled with casing cement.

8. The method as claimed in any one of claims 1 to 7, wherein after the construction approach, the geometry of each monitoring point and track is obtained as raw data by a total station, the geometry of each monitoring point and track is measured in real time during the construction process, and the elevation of the track surface is adjusted when the elevation deformation of the monitoring result relative to the raw data reaches a limit value.

9. The method of claim 8, wherein adjacent monitoring points are located at the ends of the ties on different sides during monitoring, with a tie spaced between adjacent monitoring points.

10. A method according to any one of claims 1 to 9, wherein in steps one and two the operating speed of the train is no greater than 60 Km/H.