CN115354542A

CN115354542A - Treatment method for road submerged roadbed, soil solidification material and preparation method

Info

Publication number: CN115354542A
Application number: CN202211078653.2A
Authority: CN
Inventors: 蔡玉柱; 王玮; 柴荣山; 韩延吉; 张永圣; 赵全满; 袁祥云; 霍光; 胡文军; 张灿友; 伊明刚; 张新缸; 刘建树; 冯兴广; 王根立; 李冲
Original assignee: Shandong Expressway Mingdong Highway Co ltd; Shandong Expressway Project Management Co ltd; Shandong Jianzhu University; Shandong Road and Bridge Construction Group Co Ltd
Current assignee: Shandong Expressway Mingdong Highway Co ltd; Shandong Expressway Project Management Co ltd; Shandong Jianzhu University; Shandong Road and Bridge Construction Group Co Ltd
Priority date: 2022-09-05
Filing date: 2022-09-05
Publication date: 2022-11-18
Anticipated expiration: 2042-09-05
Also published as: CN115354542B

Abstract

The invention discloses a method for treating a submerged roadbed of a highway, a soil curing material and a preparation method, and particularly relates to a method for treating a submerged roadbed of a highway, which comprises the steps of performing surface cleaning treatment on an original foundation before roadbed construction; paving solidified soil; laying geotextile for waterproof and drainage treatment; reinforcing the roadbed soil on the upper part of the roadbed, wherein the roadbed soil is divided into an upper layer and a lower layer according to different use requirements during treatment, and the mixing amount of a curing material in the upper layer of curing soil is greater than that of a curing material in the lower layer of curing soil; wherein the curing material comprises 5 to 8 parts of carbide slag, 1.5 to 3.5 parts of coal gangue, 0.5 to 2 parts of fly ash and 0.5 to 2 parts of desulfurization alkali slag. The invention fully utilizes industrial solid waste residues such as carbide slag, coal gangue and the like, adopts a clean preparation process, and develops the high-performance green environment-friendly material suitable for highway engineering construction. The method can be used for treating the immersed road foundation soil of the highway and the like, and can solidify various industrial solid wastes.

Description

Treatment method for road submerged roadbed, soil solidification material and preparation method

Technical Field

The invention belongs to the field of treatment of submerged road beds, and particularly relates to a method for treating a submerged road bed of a highway and a curing material.

Background

In actual construction projects, some geographical positions mainly include farmlands and nursery gardens, underground water levels are high, water systems are dispersed, natural water ditches are more, flood water volume is large in flood season, surface runoff is densely distributed, and multi-section roadbed is an annual water-immersed roadbed. The soaked roadbed can be wetted and the slope toe is hollowed under the actions of scouring, etching, softening and the like of water flow; under the influence of water level elevation of a submerged roadbed, roadbed soil is difficult to compact, fine granules in the filler are easy to run off, so that the roadbed is unstable, a side slope collapses, huge engineering problems are generated, and the safety and production operation of a highway are seriously threatened.

The roadbed is an important component of road infrastructure, is a main body for bearing traffic load, and is the key for ensuring the quality of road engineering. When the highway subgrade is constructed, the original ground is required to be subjected to surface cleaning treatment, then the original subgrade is compacted, the compaction degree is required to be more than or equal to 90%, but the compaction degree is difficult to achieve when the original subgrade soil has high water content, and the compaction degree is difficult to meet the standard requirement. The current common method is to fill 40cm thick stone slag after surface cleaning or treat foundation soil by adopting traditional materials of cement or lime. Meanwhile, in order to ensure that the deflection of the top of the roadbed meets the standard requirement, 4% -6% of cement is generally adopted to treat roadbed soil within about 40cm of the top of the roadbed; however, as the prices of lime, cement, broken stone and other building materials rise, the engineering cost pressure increases sharply, and meanwhile, a large amount of industrial wastes such as carbide slag, coal gangue, fly ash, silica fume, caustic sludge, blast furnace slag and the like are huge, so that a large amount of deposits are caused, not only land is occupied, but also the environment is seriously polluted.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a method for treating a submerged roadbed of a highway, which mixes carbide slag, coal gangue powder, fly ash, desulfurized alkali slag and the like for solidifying roadbed silty clay, and adopts different mixing amounts of solidifying materials at different submerged parts, so as to accurately solve the problems of diseases of the submerged roadbed, utilization of industrial solid wastes and the like, greatly reduce the construction cost and have obvious environmental, economic and social benefits.

In order to realize the purpose, the invention is realized by the following technical scheme:

in a first aspect, an embodiment of the present invention provides a method for treating a submerged road bed of a highway, including:

step 1, performing surface cleaning treatment on an original foundation before roadbed construction;

step 2, additionally paving solidified soil, wherein the solidified soil consists of silty clay and solidified materials, and 6-8 parts of the solidified materials are doped in 100 parts of the silty clay;

step 3, laying geotextile for waterproof and drainage treatment;

step 4, reinforcing the roadbed soil on the upper part of the roadbed, wherein the roadbed soil is divided into an upper layer and a lower layer according to different use requirements during treatment, the mixing amount of the curing material in every 100 parts of powdery clay in the upper layer of curing soil is 8-10 parts, and the mixing amount of the curing material in every 100 parts of powdery clay in the lower layer of curing soil is 6-8 parts;

the curing material comprises 5-8 parts of carbide slag, 1.5-3.5 parts of coal gangue, 0.5-2 parts of fly ash and 0.5-2 parts of desulfurization alkaline residue.

In a second aspect, the invention also provides a soil solidifying material, which comprises 5-8 parts of carbide slag, 1.5-3.5 parts of coal gangue, 0.5-2 parts of fly ash and 0.5-2 parts of desulfurized alkaline residue.

In a third aspect, the invention also provides a preparation method of the soil solidifying material, which comprises the following steps:

a. because the water content of the produced carbide slag is as high as more than 90 percent, the carbide slag is difficult to use, and the carbide slag is dehydrated to be less than 10 percent in order to ensure that the carbide slag is uniformly dispersed in the soil and the water content of the solidified soil is better controlled;

b. grinding the coal gangue to be less than 0.4mm, and calcining the coal gangue after grinding, wherein the calcining temperature is about 800 ℃, so as to activate the activity of the coal gangue;

c. sieving the carbide slag, the coal gangue, the fly ash and the desulfurization alkali slag obtained in the step a and the step b;

d. mixing 4 kinds of powder according to the proportion of 5-8 parts of carbide slag, 1.5-3.5 parts of coal gangue, 0.5-2 parts of fly ash and 0.5-2 parts of desulfurization alkaline residue to prepare a curing material, and mixing;

e. and (3) after the steps are finished, adding 6-10 parts of curing material into 100 parts of soil for curing, uniformly mixing the curing material with the soil, determining the optimal water content through an indoor test, and finally adding water and stirring to finish the preparation of the curing soil.

The beneficial effects of the above-mentioned embodiment of the present invention are as follows:

1. the invention provides a method for treating a submerged roadbed of a highway, which comprises the steps of newly treating reinforced soil, adding a new curing material into the reinforced soil, wherein the curing material has good water stability, then treating the cured soil on the top of a roadbed, improving the overall bearing capacity and the water stability of the roadbed, reducing the possibility of corroding a pavement structure due to water corrosion of the roadbed, greatly reducing the occurrence of diseases of the submerged roadbed, simultaneously reducing the using amount of cement by replacing the cement, increasing economic and environmental benefits, carrying out different reinforcement treatments, namely layering treatments on the roadbed soil above the roadbed according to the bearing condition of the pavement, and saving the cost while requiring the blending amount of the curing material in the upper layer of the cured soil to be larger than that in the lower layer of the cured soil so as to meet the stress requirement.

2. The invention uses the solidified soil and the geotextile for the treatment of the original foundation of the water soaking path, reduces the use of sand and stone materials or cement, has good water preventing and discharging effect, reduces the erosion of the rising of underground water and capillary water to the roadbed, can effectively reduce the damage of the roadbed, and also brings good economic and environmental benefits.

3. The invention carries out solidification by doping 6 to 10 parts of solidifying material in 100 parts of soil, wherein the solidifying material comprises 5 to 8 parts of carbide slag, 1.5 to 3.5 parts of coal gangue, 0.5 to 2 parts of coal ash and 0.5 to 2 parts of desulfurization alkali residue. The solidifying material adopts industrial solid wastes without doping an alkali activator, reduces the cement consumption, recycles the industrial solid wastes, greatly increases the environmental benefit, replaces cement, greatly reduces the construction cost and has obvious economic benefit.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.

FIG. 1 illustrates the application of the cured material of the present invention;

FIG. 2 is a silty clay grading curve of the present invention;

FIG. 3 is a drawing of a laboratory test specimen according to the present invention;

FIG. 4 is a diagram of the dry-wet cycle test and the soaking test of the present invention;

FIG. 5 (a) is a graph showing the change of strength of stabilized soil doped with 6% of a curing material after dry-wet cycles;

FIG. 5 (b) is a graph showing the change of strength of stabilized soil doped with 8% of the curing material after dry and wet cycles;

FIG. 5 (c) is a graph showing the change in strength of stabilized soil doped with 10% of a curing material after dry-wet cycles;

FIG. 6 (a) is a graph showing the strength change of stabilized soil doped with 6% of curing material before and after immersion;

FIG. 6 (b) is a graph showing the strength change of stabilized soil doped with 8% of curing material before and after immersion;

FIG. 6 (c) is a graph showing the strength change of stabilized soil doped with 10% of curing material before and after immersion;

FIG. 7 is a graph of the change in stabilized soil quality after wet and dry cycles in accordance with the present invention;

FIG. 8 is a diagram showing the change in stabilized soil quality before and after immersion in water according to the present invention;

FIG. 9 is a graph showing the pH value of stabilized soil before and after wetting and drying according to the present invention;

table 1 shows the main physical mechanical parameters of the silty clay of the present invention;

table 2 shows the oxide composition of each material of the present invention;

table 3 shows the economic benefit comparison between the improvement of each ton of soil and cement;

Detailed Description

It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an", and/or "the" are intended to include the plural forms as well, unless the invention expressly state otherwise, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof;

as described in the background of the invention, the defects in the prior art are that in order to solve the technical problems, the invention provides a method for treating a road soaking subgrade, a soil solidification material and a preparation method.

The invention discloses a method for treating a submerged roadbed of a highway and a curing material, which provides a comprehensive treatment method for the submerged roadbed and a novel soil curing material on the basis of the protection of the original submerged roadbed, wherein the application condition is shown in figure 1; after the surface of the original roadbed is cleaned, solidified soil with a certain height is paved, then geotextile is paved, water drainage treatment is carried out, and simultaneously the solidified soil is also paved on the top of the roadbed at the upper part of the roadbed, wherein the solidified soil comprises an upper layer and a lower layer.

Specifically, the comprehensive treatment method for the submerged roadbed provided by the embodiment includes the following steps:

clearing and reinforcing the original roadbed;

laying geotextile for waterproof and drainage treatment;

and (5) reinforcing the roadbed soil on the roadbed.

The concrete scheme of the original roadbed surface cleaning and reinforcing treatment is that the original roadbed surface cleaning treatment is carried out before roadbed construction, the surface cleaning thickness is larger than or equal to 30cm, then solidified soil with the thickness of 30 cm-50 cm is paved, the roadbed is required to form a road arch with a high middle part and low two sides during paving construction, and the slope of the road arch is 4%. The curing material in the curing soil is the novel curing material, and the mixing amount of 100 parts of curing material in the soil is 6-8 parts.

The geotextile laid waterproof and drainage treatment is laid after foundation reinforcement treatment, so that adverse effects on a roadbed caused by rising of underground water and capillary water are prevented, meanwhile, the underground water and the capillary water at the lower part can be condensed at the bottom of the geotextile and are discharged to two sides of the roadbed along the direction of a road arch, the geotextile is produced by Shandong auspicious engineering materials Limited company in Taian city of Shandong province, and the waterproof and drainage effects are good.

The concrete method for strengthening the roadbed soil on the roadbed is to cure the roadbed soil within the range of 40-60 cm above the roadbed, the roadbed is divided into an upper layer and a lower layer according to different use requirements during treatment, each layer is 20-30 cm, and the used curing material is the novel curing material. The road bed is the foundation of the road surface, bears the load transmitted from the road surface, the performance requirement on the road bed is gradually reduced, and the bearing capacity of the upper road bed is larger than that of the lower road bed. Meanwhile, in order to reduce the construction cost, the design of two layers of solidified soil is adopted, the mixing amount of the solidified material in each 100 parts of soil in the upper layer of solidified soil is 8-10 parts (the strength is similar to 6% cement), and the mixing amount of the solidified material in each 100 parts of soil in the lower layer of solidified soil is 6-8 parts (the strength is similar to 4% cement).

Further, the novel soil solidifying material comprises the following components in percentage by weight: the soil solidification is carried out by doping 6-10 parts of solidifying material into 100 parts of silty clay, the main parameters and grading curve of the subgrade silty clay are shown in table 1 and figure 2, wherein the solidifying material comprises 5-8 parts of carbide slag, 1.5-3.5 parts of coal gangue, 0.5-2 parts of fly ash and 0.5-2 parts of desulfurization alkali slag.

Furthermore, the four materials can reasonably provide Ca within the value range ²⁺ 、Si ⁴⁺ 、Al ³⁺ 、OH ^2- And effective ions are generated, so that a series of hydration products are generated in the reaction to improve the strength of the stabilized soil, wherein the alkaline environment required by the reaction is mainly provided by carbide slag and desulfurized alkaline slag.

TABLE 1 basic soil parameters tested

The preparation method of the novel soil solidifying material comprises the following steps:

a. dewatering carbide slag to below 10%, and drying in the sun for a certain time if there is pungent smell.

b. Grinding the coal gangue to be less than 0.4mm, and calcining the coal gangue after grinding, wherein the calcining temperature is about 800 ℃, so as to activate the activity of the coal gangue.

c. And c, sieving the carbide slag, the coal gangue, the fly ash and the desulfurization alkali slag obtained in the steps a and b by using a 0.4mm sieve to ensure that the fineness of the carbide slag, the coal gangue, the fly ash and the desulfurization alkali slag meets the requirement.

d. Mixing 4 kinds of powder according to the proportion of 5-8 parts of carbide slag, 1.5-3.5 parts of coal gangue, 0.5-2 parts of fly ash and 0.5-2 parts of desulfurization alkaline residue to prepare a curing material, and uniformly mixing the curing material by using a stirrer.

e. And after the steps are finished, 6-10 parts of curing materials are added into 100 parts of soil for curing, the curing materials are uniformly mixed with the soil, the optimal water content is determined through indoor tests, and finally, water is added for stirring to finish the preparation of the curing soil.

Further, the soil solidification material has an oxide component obtained by XRF test of each material and an oxide component after mixing.

Furthermore, the oxide components obtained by XRF test of the materials and the oxide components after mixing are shown in Table 2, the CaO content of the carbide slag is required to be more than or equal to 60%, and the SiO content of the coal gangue is required to be more than or equal to 60% ₂ 、Al ₂ O ₃ The content is more than or equal to 35 percent respectively, and the fly ash SiO ₂ 、Al ₂ O ₃ The content is more than or equal to 30 percent respectively, and the content of each alkaline residue is not required.

Table 2 table of oxide compositions of respective materials

Furthermore, the test piece used in the water stability test refers to road inorganic binder stable material test regulation JTG E51-2009 to prepare a cylindrical test piece with the size of 50mm multiplied by 50mm, and the compactness is 98%. Immediately after the preparation of the test piece, the test piece is put into a standard curing box with the temperature of 21 +/-2 ℃ and the relative humidity of 95 percent and cured to the required age, and the test piece is shown in figure 3.

Further, durability was tested by an indoor test, and the cured soil was subjected to a water stability test to test the strength and mass loss at 7d age, the test procedure is shown in fig. 4, and the test results are shown in fig. 5 (a) to 8.

Further, as can be seen from fig. 5 (a), 5 (b) and 5 (c), the unconfined compressive strengths of the 6%, 8% and 10% doped 7D-age solidified soil after 0 dry-wet cycle are 2.65MPa, 2.99MPa and 4.61MPa respectively, and the unconfined compressive strengths of the solidified soil after 6 dry-wet cycles are 1.66MPa, 4.12MPa and 4.14MPa respectively, so that the strength meets the requirements of the road asphalt pavement design specification JTG D50-2017 limewater fly ash stable type highway extreme weight and the extra-heavy traffic underlayment of more than or equal to 1.1MPa, and the water stability is good.

Further, as shown in fig. 6 (a), 6 (b) and 6 (c), the compressive strength of the 7 d-age solidified soil before and after 30 days of water immersion is not laterally limited, but is limited, the strength of the soil after water immersion is reduced by 22.2%, 15.7% and 19.6% respectively under 6%, 8% and 10%, and the strength of the soil after water immersion can still meet the requirements of the specifications and is good in water stability.

Further, as can be seen from fig. 7 and 8, after the solidified soil in the 7d age is subjected to the dry-wet cycle test and the soaking test, the mass of the test piece shows a tendency that the water absorption is greatly increased and then gradually decreased, but the final mass change rate is small, so that the influence of the water environment on the quality of the solidified soil is small, and the water stability is good.

Furthermore, in order to reveal the effect of the non-added alkali activator on the activation of the mixed soil, the pH value of the mixed soil needs to be tested, and the test result is shown in FIG. 9, which is known from FIG. 9.

Furthermore, the industrial solid waste is adopted to solidify the soil, and a conventional alkali activator is not added, so that the construction cost is greatly reduced.

Further, the solidified soil has good economic benefits, and the economic benefit ratio of improvement to cement per ton of soil is shown in table 3.

TABLE 3 comparison of soil improvement per ton with cement economic benefits

The invention is further illustrated by the following specific examples

Example 1:

the embodiment discloses a treatment method for a road bed on a submerged roadbed; the upper road bed is paved into two layers, 8% of curing material is doped outside the lower layer, 10% of curing material is doped outside the upper layer, and the lower layer is constructed by the following steps:

a. and arranging plain soil distribution grids. During the plain soil filling construction, firstly putting side lines, erecting a construction scale, and setting up 18m fillers according to the designed thickness of 20cm and the number of the fillers in each vehicle ³ And calculating and setting the size of the feeding grid, and drawing a range on the roadbed by using lime.

b. And (5) paving plain soil. The paving of the filler is carried out one day before the mixture is paved, the filler is uniformly paved on a road roller by using a bulldozer, the compactness, the flatness, the standard height and the like are detected by static pressure, the filler is molded by a softening coefficient of 1.2 to be 24cm, and the optimal water content is finally tested to ensure that the filler meets the requirement.

c. And (4) spreading the mixture. And d, adding the mixture according to the adding amount of 8%, and calculating the mass of the mixture per gridding element soil mass through the step a.

d. And (4) mixing. The road mixer is used for mixing, the mixing depth is required to reach the top of the lower bearing layer, the road mixer slightly damages the surface of the lower bearing layer, the upper layer and the lower layer are convenient to bond, and faults are avoided. And after the mixing is finished, monitoring the content of the mixture, and ensuring that the optimal water content is within an error range.

e. And (7) leveling. And d, after the steps a-d are finished, quickly stabilizing the pressure by using a bulldozer, and immediately measuring the elevation after the pressure stabilization is finished so as to guide the shaping of a land leveler. Each leveling is performed according to the required grade and road crown.

f. And (5) compacting. And (3) carrying out vibration compaction by adopting a 26t road roller, controlling the speed of vibration rolling to be 2.0-2.5 km/h, carrying out compaction degree detection by strong vibration for many times, and carrying out compaction again if the compaction degree is unqualified until the compaction degree is qualified.

g. And (5) maintaining. After all the compaction is finished, 7d health preservation is carried out, the traffic should be closed during the health preservation, and except for the watering cart and the small commuter vehicle, other vehicles are strictly forbidden to pass.

The upper layer construction method is basically the same as the steps, except that the mixing amount of the curing material is 10 percent.

Example 2:

the construction of this example is substantially the same as that of example 1 except that the amount of the curing material is 6% and the thickness of the drainage prevention and drainage layer is 40cm, and a geotextile is laid on the upper part of the drainage prevention and drainage layer to prevent the influence of capillary water rise on the roadbed.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. 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

1. A method for treating a submerged road bed of a highway is characterized by comprising the following steps:

step 3, laying geotextile for waterproof and drainage treatment;

step 4, reinforcing the roadbed soil on the upper part of the roadbed, wherein the roadbed soil is divided into an upper layer and a lower layer according to different use requirements during treatment, and the mixing amount of the curing materials in the upper layer of curing soil is larger than that of the curing materials in the lower layer of curing soil;

2. A method as claimed in claim 1, wherein in step 2, solidified soil is applied to form an arch with a high middle and low sides.

3. The method for treating the submerged road foundation of the road as claimed in claim 1, wherein the surface cleaning thickness in the step 1 is more than or equal to 30cm.

4. The method for treating the submerged road foundation of claim 1, wherein in the step 2, 30-50 cm of solidified soil is paved.

5. The method of claim 1, wherein the roadbed soil is cured within a range of 40cm to 60cm above the roadbed, and the upper and lower layers are 20cm to 30cm apart.

6. The method for treating the submersed road foundation of claim 1, wherein the amount of the curing material added to each 100 parts of the silty clay in the upper layer of the curing soil is 8-10 parts, and the amount of the curing material added to each 100 parts of the silty clay in the lower layer of the curing soil is 6-8 parts.

7. The soil solidifying material is characterized by comprising 5-8 parts of carbide slag, 1.5-3.5 parts of coal gangue, 0.5-2 parts of coal ash and 0.5-2 parts of desulfurization alkali slag.

8. The method for preparing a soil solidifying material according to claim 7, wherein the method comprises the steps of:

a. dewatering the carbide slag to below 10%;

9. The method for preparing soil solidifying material according to claim 7, wherein the oxide component obtained by XRF test and the mixed oxide component of each material require that CaO content of carbide slag is not less than 60%, and SiO content of coal gangue is not less than 60% ₂ 、Al ₂ O ₃ The content is more than or equal to 35 percent respectively, and the fly ash SiO ₂ 、Al ₂ O ₃ The content is more than or equal to 30 percent respectively, and the content of the alkaline residue is not required.

10. The method for preparing a soil solidifying material according to claim 7, wherein the durability of the solidified soil is measured by an indoor test, and a dry-wet cycle test and a water stability test are performed thereon, and the strength and the water stability are analyzed from the test results.