阅读说明：本技术 一种粉煤灰堆积场地城市道路路基注浆加固施工工法 (Grouting reinforcement construction method for urban road subgrade in coal ash stacking site ) 是由 马维佳 张继峰 李宗杰 刘洪洋 张志远 于 2021-08-25 设计创作，主要内容包括：本发明公开了一种粉煤灰堆积场地城市道路路基注浆加固施工工法,属于粉煤灰堆积场地的路基加固处理技术领域,包括确立施工目标位置,清理场地,测量放线确定打桩注浆的注浆孔孔位,并制作注浆管,采用螺旋钻机成孔,钻孔穿越粉煤灰土层至原状土层以下深度范围为0.4-0.6m,注浆孔直径长度范围为80-100mm,注浆孔间距1m,成孔后清孔,将清理后的注浆孔放入注浆管,在孔内的注浆管周围均匀填砂,在孔口上部1m范围内的封孔管使用调和之后的水泥砂浆封孔,注浆封孔24h后,使用纯水泥浆进行压力注浆,监控注浆压力值,注浆施工顺序为先周边再中间,进行隔孔施工,达到提高地基承载力、抗变形能力、改良工程不稳定特性的目的,减少了处理时长,降低处理费用。(The invention discloses a construction method for grouting and reinforcing a roadbed of an urban road in a fly ash stacking site, which belongs to the technical field of roadbed reinforcement treatment of the fly ash stacking site, and comprises the steps of establishing a construction target position, cleaning the site, measuring and setting-out to determine the position of a grouting hole of pile-driving grouting, manufacturing a grouting pipe, forming a hole by adopting a spiral drilling machine, enabling the drilled hole to penetrate through the fly ash soil layer to the depth range below an original soil layer to be 0.4-0.6m, enabling the diameter and the length of the grouting hole to be 80-100mm, enabling the distance between the grouting holes to be 1m, cleaning the hole after hole forming, placing the cleaned grouting hole into the grouting pipe, uniformly filling sand around the grouting pipe in the hole, sealing the hole in the hole within the range of 1m above the hole by using blended cement mortar, performing pressure grouting after grouting for sealing the hole for 24 hours, monitoring the grouting pressure value, and performing grouting in the sequence of first periphery and then in the middle, the construction of the isolation hole is carried out, so that the purposes of improving the bearing capacity and the deformation resistance of the foundation and improving the unstable characteristics of the engineering are achieved, the processing time is shortened, and the processing cost is reduced.)

1. A construction method for grouting and reinforcing a roadbed of an urban road in a fly ash stacking site is characterized by comprising the following operation processes:

step 1, firstly, establishing a construction target position, cleaning a field, measuring and setting off to determine the position of a grouting hole (3) for pile driving grouting, and manufacturing a grouting pipe (4);

step 2, after the grouting holes (3) are established, forming holes by using a spiral drilling machine, wherein the depth range of the drilled holes from the fly ash soil layer (1) to the position below the original soil layer (2) is 0.4-0.6m, the diameter and length ranges of the grouting holes (3) are 80-100mm, the distance between the grouting holes (3) is 1m, and cleaning the holes after forming the holes;

step 3, placing the cleaned grouting hole (3) into a grouting pipe (4), uniformly filling sand around the grouting pipe (4) in the hole, and sealing the hole by using the blended cement mortar in a hole sealing pipe (5) within the range of 1m above the hole opening;

step 4, after grouting and hole sealing are carried out for 24 hours, pressure grouting is carried out by using pure cement slurry, the grouting pressure value is monitored, and hole isolation construction is carried out in the grouting construction sequence of firstly carrying out periphery and then carrying out middle;

step 5, in the grouting reinforcement process, when the pressure suddenly rises or slurry overflows from the hole wall and the ground, stopping grouting immediately and finishing;

and 6, carrying out the next construction 28 days after the grouting is finished.

2. The grouting reinforcement construction method for the roadbed of the urban road with the fly ash stacking site as claimed in claim 1, wherein the grouting pipe (4) in the step 1 is a steel pipe with the diameter and the wall thickness of 25mm, the grouting pipe (4) comprises a hole sealing pipe (5), a permeation pipe (6) is fixedly connected below the hole sealing pipe (5), and a soil breaking head (7) is fixedly connected to the lower end of the permeation pipe (6).

3. The grouting reinforcement construction method for the roadbed of the urban road with the fly ash stacking site as claimed in claim 2, wherein the length of the hole sealing pipe (5) is 1m, the penetration holes (61) are formed in the periphery of the penetration pipe (6), and the penetration holes (61) are arranged in a quincunx shape by opening 3 holes in the periphery of the penetration pipe (6) at intervals of 500 mm.

4. The grouting reinforcement construction method for the roadbed of the urban road with the fly ash stacking site as claimed in claim 3, wherein the value obtained by subtracting the longitudinal depth of the fly ash soil layer (1) from the sum of the lengths of the permeation tube (6) and the hole sealing tube (5) is greater than 0.5 m.

5. The construction method for grouting and reinforcing the roadbed of the urban road with the fly ash stacking site as claimed in claim 1, wherein the volume blending ratio of the cement mortar blended in the step 3 is as follows: cement: sand: water =1:2: 0.7.

6. the grouting reinforcement construction method for the roadbed of the urban road with the fly ash stacking site as claimed in claim 1, wherein the cement in the pure cement slurry in the step 4 is P.O42.5 ordinary portland cement, the water cement ratio blending range is 0.4-0.5, the grouting pressure is 0.5MPa, the grouting stopping pressure is less than or equal to 1MPa, and the grouting injection rate is greater than or equal to 0.2.

Technical Field

The invention relates to the technical field of roadbed reinforcement treatment of a fly ash stacking site, in particular to a grouting reinforcement construction method for an urban road roadbed of the fly ash stacking site.

Background

The fly ash is fine ash collected from flue gas generated after coal combustion, is main solid waste discharged by a coal-fired power plant, can be used as a filling material of an embankment, is already applied to a large number of projects, and has the characteristics of light dead weight, high strength, small compressibility, good water permeability and the like compared with common fine soil;

for the coal ash stacking field, specific engineering factors cannot be considered when the coal ash is deposited at that time, the coal ash stacking field often has the characteristics of high water content, high compressibility, low compactness and weak bearing capacity, the engineering property is unstable and is not suitable for being directly used as a roadbed of an urban highway, however, due to the objective limitation of road route selection, some roads must pass through the coal ash field, and how to treat the field is always a difficult problem which is troubling the engineering field, and because the conditions of different fields are greatly different, such as the self property of the coal ash, the difference of filling distribution of the soil layer of the field and the like, a treatment method is difficult to directly refer to for use, and a targeted foundation treatment scheme is provided for the specific condition of the coal ash stacking field;

at present, the method for replacing and filling the coal ash piling site has the problems of long time consumption, large earth volume, large occupied area, high cost and environmental pollution in the existing methods for replacing and filling the coal ash piling site, and the method can only be applied to small-area sites and is not feasible for large-area sites filled with deep coal ash, the construction noise of the method for forcibly filling the coal ash is high, the urban environment interference is large, the deep layer is difficult to achieve the compaction effect, and the reinforcing depth is limited.

Disclosure of Invention

The invention aims to solve the problems that the project in the existing treatment project using the fly ash stacking site consumes long time, occupies a large area, has high cost, generates noise to cause urban noise pollution, is difficult to achieve the compaction effect in the deep layer and has limited reinforcement depth.

In order to achieve the purpose, the invention adopts the following technical scheme:

a construction method for grouting and reinforcing a roadbed of an urban road in a fly ash stacking site comprises the following operation processes:

step 1, firstly, establishing a construction target position, cleaning a field, measuring and setting off to determine the position of a grouting hole for piling and grouting, and manufacturing a grouting pipe;

step 2, after the position of a grouting hole is determined, a spiral drilling machine is adopted to form the hole, the depth range of the drilled hole penetrating through the fly ash soil layer to the position below an original soil layer is 0.4-0.6m, the diameter and length range of the grouting hole is 80-100mm, the distance between the grouting holes is 1m, and the hole is cleaned after the hole is formed;

step 3, placing the cleaned grouting hole into a grouting pipe, uniformly filling sand around the grouting pipe in the hole, and sealing the hole in the hole sealing pipe within the range of 1m above the hole opening by using the blended cement mortar;

step 4, after grouting and hole sealing are carried out for 24 hours, pressure grouting is carried out by using pure cement slurry, the grouting pressure value is monitored, and hole isolation construction is carried out in the grouting construction sequence of firstly carrying out periphery and then carrying out middle;

step 5, in the grouting reinforcement process, when the pressure suddenly rises or slurry overflows from the hole wall and the ground, stopping grouting immediately and finishing;

and 6, carrying out the next construction 28 days after the grouting is finished.

For better infiltration fly ash soil layer, preferably, the slip casting pipe in step 1 adopts the steel pipe that diameter wall thickness is 25mm, the slip casting pipe is including the hole sealing pipe, fixedly connected with infiltration pipe below the hole sealing pipe, infiltration pipe lower extreme fixedly connected with breaks ground head.

In order to accelerate the permeation speed, preferably, the length of the hole sealing pipe is 1m, permeation holes are formed in the periphery of the permeation pipe, and 3 holes are formed in the periphery of the permeation pipe at intervals of 500mm and are arranged in a quincunx shape.

In order to fully utilize the fly ash soil layer, the value of the sum of the lengths of the penetration pipe and the hole sealing pipe minus the longitudinal depth of the fly ash soil layer is preferably more than 0.5 m.

In order to make the sealing more tight, preferably, the volume blending ratio of the cement mortar blended in the step 3 is: cement: sand: water =1:2: 0.7.

For safe grouting, preferably, the cement in the pure cement slurry in the step 4 is p.o42.5 ordinary portland cement, the water cement ratio blending range is 0.4-0.5, the grouting pressure is 0.5MPa, the grouting termination pressure is less than or equal to 1MPa, and the grouting injection rate is greater than or equal to 0.2.

Compared with the prior art, the invention provides a construction method for grouting and reinforcing the roadbed of the urban road in the fly ash stacking site, which has the following beneficial effects:

1. the method injects cement slurry into the fly ash soil layer, and can combine with the active ingredients of the fly ash to form a stable whole, thereby achieving the purposes of improving the bearing capacity and the anti-deformation capability of the foundation and improving the unstable characteristics of the engineering, reducing the treatment time, the treatment cost, the urban noise factor and achieving the compaction effect at the deep level of the stacking site.

2. The method has the advantages of high construction speed, less interference and the like, greatly reduces the influence on the surrounding environment in the construction process, shortens the construction period, reduces the construction cost, reduces the labor input and improves the engineering benefit.

Drawings

FIG. 1 is a schematic view of a roadbed cross section structure of a construction method for grouting and reinforcing a roadbed of an urban road in a fly ash stacking site, provided by the invention;

FIG. 2 is a schematic view of a grouting pipe structure of a construction method for grouting and reinforcing a roadbed of an urban road in a fly ash stacking site, provided by the invention;

fig. 3 is a schematic diagram of a roadbed grouting section structure of the construction method for grouting and reinforcing the roadbed of the urban road in the fly ash stacking site.

In the figure: 1. a fly ash soil layer; 2. an undisturbed soil layer; 3. grouting holes; 4. a grouting pipe; 5. sealing the hole pipe; 6. a permeate tube; 61. a penetration hole; 7. and (6) a soil breaking head.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

Example 1:

referring to fig. 1-3, a construction method for grouting and reinforcing a roadbed of an urban road in a fly ash stacking site comprises the following operation processes:

step 1, firstly, establishing a construction target position, cleaning a field, measuring and setting off to determine the hole position of a grouting hole 3 for piling and grouting, and manufacturing a grouting pipe 4;

step 2, after the grouting holes 3 are determined, forming holes by using a spiral drilling machine, wherein the depth range of the drilled holes penetrating through the fly ash soil layer 1 to the position below an original soil layer 2 is 0.4-0.6m, the diameter and length range of the grouting holes 3 is 80-100mm, the distance between the grouting holes 3 is 1m, and the holes are cleaned after forming the holes;

step 3, placing the cleaned grouting hole 3 into a grouting pipe 4, uniformly filling sand around the grouting pipe 4 in the hole, and sealing the hole by using the blended cement mortar in a hole sealing pipe 5 in the range of 1m above the hole opening;

step 4, after grouting and hole sealing are carried out for 24 hours, pressure grouting is carried out by using pure cement slurry, the grouting pressure value is monitored, and hole isolation construction is carried out in the grouting construction sequence of firstly carrying out periphery and then carrying out middle;

step 5, in the grouting reinforcement process, when the pressure suddenly rises or slurry overflows from the hole wall and the ground, stopping grouting immediately and finishing;

and 6, carrying out the next construction 28 days after the grouting is finished.

The construction method injects cement slurry into the fly ash soil layer 1, and the cement slurry can be combined with the active ingredients of the fly ash to form a stable whole, so that the purposes of improving the bearing capacity and the deformation resistance of a foundation and improving the unstable characteristics of engineering are achieved, the treatment time is shortened, the treatment cost is reduced, the urban noise factor is reduced, and the compaction effect is also achieved at the deep level of a stacking site.

Example 2:

referring to fig. 1 to 3, a construction method for grouting and reinforcing a roadbed of an urban road in a fly ash stacking site is substantially the same as that of example 1, and further, in the specific implementation process, firstly, the construction target position is established, sundries in a construction site are cleaned, the distance is measured, the line is laid out, the hole position 3 of a grouting hole for piling and grouting is determined, and a grouting pipe 4 is manufactured, the grouting pipe 4 is a steel pipe with the diameter and the wall thickness of 25mm, the grouting pipe 4 comprises a hole sealing pipe 5, the length of the hole sealing pipe 5 is 1m, a penetration pipe 6 is fixedly connected below the hole sealing pipe 5, penetration holes 61 are arranged on the periphery of the penetration pipe 6, the penetration holes 61 are arranged at intervals of 500mm, the circumference of the penetration pipe 6 is provided with 3 holes which are arranged in a quincunx shape, the numerical value of the longitudinal depth of the fly ash soil layer 1 subtracted from the sum of the lengths of the penetration pipe 6 and the hole sealing pipe 5 is more than 0.5m, and the lower end of the penetration pipe 6 is fixedly connected with a ground breaking head 7;

after 3 hole sites of the grouting holes are determined, a spiral drilling machine is adopted to form the holes, the depth range of the drilled holes from 1 to 2 original soil layers is 0.4-0.6m, the diameter and length range of the grouting holes 3 is 80-100mm, the distance between the grouting holes 3 is 1m, the holes are cleaned after the holes are formed, the cleaned grouting holes 3 are placed into the grouting pipes 4, sand is uniformly filled around the grouting pipes 4 in the holes, cement mortar is blended, and the blended volume blending ratio is as follows: cement: sand: water =1:2:0.7, and the hole sealing pipe 5 in the range of 1m above the hole opening is sealed by using the blended cement mortar;

after grouting and hole sealing are carried out for 24 hours, pressure grouting is carried out by using pure cement slurry, the cement is P.O42.5 ordinary portland cement, the water cement ratio blending range is 0.4-0.5, the grouting pressure is 0.5MPa, the grouting termination pressure is less than or equal to 1MPa, the grouting injection rate is greater than or equal to 0.2, the grouting pressure value is monitored, the grouting construction sequence is that grouting is carried out from the periphery to the middle, hole isolation construction is carried out, and when the pressure suddenly rises or slurry overflows from the hole wall and the ground, the grouting is immediately stopped for finishing;

and carrying out the next construction 28 days after the grouting is finished.

The construction method injects cement slurry into the fly ash soil layer 1, and the cement slurry can be combined with the active ingredients of the fly ash to form a stable whole, so that the purposes of improving the bearing capacity and the deformation resistance of a foundation and improving the unstable characteristics of engineering are achieved, the treatment time is shortened, the treatment cost is reduced, the urban noise factor is reduced, and the compaction effect is also achieved at the deep level of a stacking site.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be able to cover the technical scope of the present invention and the equivalent alternatives or modifications according to the technical solution and the inventive concept of the present invention within the technical scope of the present invention.