CN115354542B

CN115354542B - Treatment method for highway immersed roadbed, soil curing material and preparation method

Info

Publication number: CN115354542B
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: 2023-06-06
Anticipated expiration: 2042-09-05
Also published as: CN115354542A

Abstract

The invention discloses a highway immersed roadbed treatment method, a soil curing material and a preparation method, in particular to an expressway immersed roadbed treatment method which comprises the steps of carrying out surface cleaning treatment on an original foundation before roadbed construction; paving solidified soil; paving geotextile for water-proof and drainage treatment; reinforcing the roadbed soil at the upper part of the roadbed, wherein the upper layer and the lower layer are divided according to different use requirements when in treatment, and the mixing amount of the curing material in the curing soil at the upper layer is larger than that in the curing soil at the lower layer; wherein the curing material comprises 5-8 parts of carbide slag, 1.5-3.5 parts of gangue, 0.5-2 parts of fly ash and 0.5-2 parts of desulfurization alkaline slag. The invention fully utilizes the 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. Not only can be used for the treatment of the foundation soil of the expressway, but also can consolidate various industrial solid wastes.

Description

Treatment method for highway immersed roadbed, soil curing material and preparation method

Technical Field

The invention belongs to the field of treatment of immersed roadbed, and particularly relates to a method for treating an immersed roadbed of a highway and a curing material.

Background

In actual construction projects, some geographic positions are mainly farmlands and nurseries, the underground water level is high, the water system is dispersed, natural ditches are more, flood volume in flood season is large, surface runoffs are densely distributed, and the multi-section roadbed is a perennial water-immersed roadbed. Under the effects of flushing, etching, softening and the like of water flow, the immersed roadbed can cause wetting of the roadbed and hollowing of the slope foot; under the influence of water level lifting, roadbed soil is difficult to compact, fine particles in filler are easy to run off, the roadbed is unstable, the side slope collapses, huge engineering problems are generated, and the safety of roads and production operation are seriously threatened.

The roadbed is an important component of road infrastructure, is a main body for bearing traffic load, and is a key for guaranteeing the quality of road engineering. The surface cleaning treatment is required to be carried out on the original ground during the construction of the highway subgrade, then the original ground is compacted, the compactness is required to be more than or equal to 90 percent, but the compaction is difficult to be carried out when the water content of the original ground is large, and the compactness is difficult to meet the standard requirement. At present, the common method is to fill 40cm thick stone slag after surface cleaning or to treat foundation soil by adopting cement or lime which are traditional materials. Meanwhile, in order to ensure that the deflection of the top of the roadbed meets the standard requirement, 4-6% cement is generally adopted to treat roadbed soil within the range of about 40cm of the top of the roadbed; however, as the prices of building materials such as lime, cement, broken stone and the like rise, the engineering cost pressure increases rapidly, 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 wastes are accumulated, thereby not only occupying land, but also seriously polluting the environment.

Disclosure of Invention

Aiming at the defects existing in the prior art, the invention aims to provide a highway immersed roadbed treatment method, which is characterized in that carbide slag, gangue powder, fly ash, desulfurization alkaline residue and the like are mixed and used for roadbed powder clay curing, and different mixing amounts of curing materials are adopted at different immersed parts, so that the problems of immersed roadbed diseases, industrial solid waste recycling and the like are solved accurately, the engineering cost is reduced greatly, and the environmental, economic and social benefits are remarkable.

In order to achieve the above object, the present invention is realized by the following technical scheme:

in a first aspect, an embodiment of the present invention provides a method for treating a highway subgrade for immersion, as follows:

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

step 2, paving solidified soil, wherein the solidified soil consists of powdery clay and solidified materials, and 6-8 parts of the solidified materials are externally mixed in 100 parts of powdery clay;

step 3, laying geotextile water-proof and drainage treatment;

step 4, reinforcing the roadbed soil at the upper part of the roadbed, wherein the upper layer and the lower layer are divided according to different use requirements, the mixing amount of the curing material in each 100 parts of the powdery clay in the upper layer of the curing soil is 8-10 parts, and the mixing amount of the curing material in each 100 parts of the powdery clay in the lower layer of the curing soil is 6-8 parts;

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

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 gangue, 0.5-2 parts of fly ash and 0.5-2 parts of desulfurization alkaline slag.

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 just produced carbide slag is up to more than 90%, the carbide slag is difficult to use, and the carbide slag is dehydrated to less than 10% 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 below 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 and the gangue obtained in the step a and the step b, and the fly ash and the desulfurization alkaline slag;

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 slag to prepare a solidified material, and mixing;

e. after the steps are finished, 6-10 parts of curing materials are externally mixed in 100 parts of soil for curing, the mixture is uniformly mixed with the soil, the optimal water content is determined through an indoor test, and finally, water is added and stirring is carried out to finish the preparation of the cured soil.

The beneficial effects of the embodiment of the invention are as follows:

1. the invention provides a highway immersed roadbed treatment method, in which reinforced soil is treated newly, new solidifying materials are added into the reinforced soil, the solidifying materials have good water stability, then the solidified soil is used for treating the top of a roadbed, the integral bearing capacity and the water stability of the roadbed are improved, the possibility of eroding a road surface structure by water eroding the roadbed is reduced, the occurrence of diseases of the immersed roadbed is greatly reduced, meanwhile, cement consumption is reduced by replacing cement, and economic and environmental benefits are increased.

2. The invention combines the solidified soil with geotextile for the original foundation treatment of the immersed roadbed, reduces the use of sand stone materials or cement, has good water-proof and drainage effects, reduces the erosion of groundwater and capillary water on the roadbed, can effectively reduce the damage of the roadbed, and brings good economic and environmental benefits as well.

3. The invention is solidified by doping 6-10 parts of solidifying material in 100 parts of soil, 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 alkaline residue. The curing material adopts industrial solid waste without adding alkali activator, thereby reducing the cement consumption, recycling the industrial solid waste, greatly increasing the environmental benefit, replacing the cement, greatly reducing the engineering cost and having obvious economic benefit.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention.

FIG. 1 is a schematic illustration of the application of the cured material of the present invention;

FIG. 2 is a graph showing the gradation of a powdery clay according to the present invention;

FIG. 3 is a drawing of an indoor test piece of the present invention;

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

FIG. 5 (a) is a graph showing the change in strength of a stabilized soil after dry and wet cycles incorporating 6% of a cured material;

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

FIG. 5 (c) is a graph showing the change in strength of a stabilized soil after dry and wet cycles incorporating 10% of a cured material;

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

FIG. 6 (b) is a graph showing the change in strength of 8% additional solidified material before and after stabilized soil is immersed in water;

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

FIG. 7 is a graph showing the change of the mass of stabilized soil after dry and wet cycle according to the present invention;

FIG. 8 is a graph showing the mass change of stabilized soil before and after soaking in water according to the present invention;

FIG. 9 is a graph showing the pH change of stabilized soil before and after dry and wet conditions in accordance with the present invention;

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

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

table 3 shows the economic benefits of the invention per ton of soil improvement versus cement;

Detailed Description

It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the invention. 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 present invention. As used herein, the singular forms also are intended to include the plural forms unless the present invention clearly dictates otherwise, and furthermore, it should be understood that when the terms "comprise" and/or "include" 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 art, the invention provides a highway water immersion roadbed treatment method, a soil curing material and a preparation method in order to solve the technical problems.

The invention discloses a method for treating a highway immersed roadbed and a curing material, which are based on the protection of the original immersed roadbed, and provides a comprehensive treatment method for the immersed roadbed, and a novel soil curing material, wherein the application situation of the novel soil curing material is shown in figure 1; after the original roadbed is cleaned, solidified soil with a certain height is paved, geotextile is paved, drainage treatment is carried out, and solidified soil is paved at the top of the roadbed on 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 immersed roadbed provided by the embodiment comprises the following steps:

cleaning the surface and reinforcing the original roadbed;

paving geotextile for water-proof and drainage treatment;

and (5) reinforcing the roadbed soil at the upper part of the roadbed.

The specific scheme of the original roadbed surface cleaning and reinforcing treatment is that the original foundation is subjected to surface cleaning treatment before roadbed construction, the surface cleaning thickness is more than or equal to 30cm, then 30 cm-50 cm of solidified soil is additionally paved, and roadbed is required to form a roadbed arch with high middle and low two sides during the additional paving construction, and the gradient of the roadbed arch is 4%. The cured material in the cured soil is the novel cured material, and the mixing amount of the cured material in 100 parts of soil is 6-8 parts.

The geotextile water-proof and drainage treatment is paved after the original foundation reinforcement treatment, so that adverse effects on the foundation 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, and the geotextile is produced by Shandong Lingxiang engineering materials limited company in Taian city of Shandong province, and has good water-proof and drainage effects.

The concrete method for the road foundation soil reinforcing treatment at the upper part of the road bed comprises the steps of carrying out curing treatment on the road foundation soil at the upper part of the road bed within the range of 40 cm-60 cm, wherein the upper layer and the lower layer are respectively divided into 20 cm-30 cm according to different use requirements during the treatment, and the used curing material is the novel curing material. The road bed is the foundation of the road surface, bears the load transmitted by the road surface, and the performance requirement on the road bed is gradually reduced, and the bearing capacity of the upper road bed is required to be larger than that of the lower road bed. Meanwhile, in order to reduce the construction cost, a 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 that of the 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 that of the 4% cement).

Further, the novel soil solidifying material is prepared from the following components in percentage by weight: the soil solidification is carried out by mixing 6-10 parts of solidifying material in 100 parts of powdery clay, main parameters and gradation curves of the roadbed powdery 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 alkaline slag.

Further, the four materials can reasonably provide Ca in the value range ²⁺ 、Si ⁴⁺ 、Al ³⁺ 、OH ^2- And (3) generating a plurality of hydration products 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 desulfurization alkaline slag.

Table 1 test soil basic parameters

The preparation method of the novel soil curing material is further as follows:

a. the carbide slag is dehydrated to be less than 10 percent, and the carbide slag is also required to be dried for a certain time if the carbide slag has pungent smell.

b. Grinding the coal gangue to below 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 and the gangue obtained in the steps a and b with a 0.4mm sieve to ensure that the fineness of the carbide slag and the gangue meets the requirements.

d. 4 kinds of powder are mixed according to the proportion of 5 to 8 parts of carbide slag, 1.5 to 3.5 parts of gangue, 0.5 to 2 parts of fly ash and 0.5 to 2 parts of desulfurization alkaline slag to prepare a solidified material, and the solidified material is uniformly mixed by a stirrer.

Further, the oxide component of each material of the soil-hardening material obtained by XRF test and the mixed oxide component.

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

TABLE 2 oxide composition of materials

Further, a cylindrical test piece having a size of 50mm×50mm was prepared by referring to JTG E51-2009 of test procedure for stable materials for inorganic binders for highway, and the degree of compaction was 98%. And (3) immediately placing the test piece into a standard curing box with the temperature of 21+/-2 ℃ and the relative humidity of 95% for curing to the required age after the test piece is prepared, wherein the test piece is shown in figure 3.

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

Further, as shown in fig. 5 (a), 5 (b) and 5 (c), the unconfined compressive strength of the cured soil of the age of 7D with the doping amount of 6%, 8% and 10% after the dry and wet circulation for 0 times is respectively 2.65MPa, 2.99MPa and 4.61MPa, the strength of the cured soil of the age of 1.66MPa, 4.12MPa and 4.14MPa after the dry and wet circulation for 6 times is respectively satisfied, the strength meets the requirements that the JTG D50-2017 lime fly ash stable expressway is extremely heavy, the extra heavy traffic base layer is more than or equal to 1.1MPa, and the water stability is good.

Further, as can be seen from fig. 6 (a), 6 (b) and 6 (c), the unconfined compressive strength of the 7d age solidified soil before and after 30 days of soaking is reduced, but the reduction degree is limited, the strength is respectively reduced by 22.2%, 15.7% and 19.6% under the conditions of 6%, 8% and 10%, and the strength still meets the requirements of the specification after soaking, and the water stability is good.

Further, as shown in fig. 7 and 8, after the dry-wet cycle test and the soaking test are performed on the 7 d-age solidified soil, 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 smaller, the influence of the water environment effect on the quality of the solidified soil is smaller, and the water stability is better.

Further, in order to reveal the effect of activating the activity of the soil mixture without adding the alkali activator, the pH value was measured, and the measurement results are shown in FIG. 9, and the results are shown in FIG. 9.

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

Further, the solidified soil has good economic benefit, and the pair of improved per ton soil and cement economic benefit is shown in table 3.

TABLE 3 comparison of soil improvement per ton and Cement economic benefits

The invention will be further described with reference to specific examples

Example 1:

the embodiment discloses a method for treating a roadbed on a water-immersed roadbed; the upper road bed is paved with two layers, the lower layer is externally doped with 8 percent of curing material, the upper layer is externally doped with 10 percent of curing material, and the lower layer construction steps are as follows:

a. and arranging plain soil material distribution grids. During the plain soil filling construction, the side lines are firstly laid, a construction scale is erected, the thickness is 20cm according to the design, and the quantity of the fillers is 18m according to each vehicle ³ And calculating and setting the size of the feeding grid, and drawing a range on the roadbed by lime.

b. And (5) spreading plain soil. The plain soil is paved one day before the mixture is paved, a bulldozer is used for evenly paving the filler on a road roller, static pressure is used for detecting compactness, flatness, elevation and the like, the filler is molded for 24cm through a softness coefficient of 1.2, and finally, the optimal water content is tested to ensure that the filler meets the requirement.

c. Spreading the mixture. The mixture was blended according to the 8% blending amount, and the mass of the mixture was calculated per mass of the gridding soil by the step a.

d. Mixing. The road mixer is used for mixing, the mixing depth is up to the top of the lower bearing layer, so that 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. After the mixing is completed, the content of the mixture is monitored, and the optimal water content is ensured to be within an error range.

e. Leveling. And d, after the steps a-d are finished, performing quick voltage stabilization by using a bulldozer, and immediately performing elevation measurement after the voltage stabilization is finished to guide the grader to reshape. Each leveling is performed according to the required gradient and road arch.

f. Compacting. And (3) carrying out vibration compaction by adopting a 26t compaction path, controlling the vibration rolling travelling speed to be 2.0-2.5 km/h, carrying out compaction degree detection for Jiang Zhenduo times, and carrying out compaction again if the compaction degree is unqualified until the compaction degree is qualified.

g. And (5) maintaining. After all compacting, 7d health maintenance is carried out, traffic is closed during the health maintenance, and other vehicles except the watering vehicles and the small-sized commuter vehicles are strictly forbidden to pass.

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

Example 2:

the construction of this example was substantially the same as that of example 1 except that the amount of the cured material was 6%, the thickness of the water drainage preventing layer was 40cm, and geotextiles were laid on the upper portion of the water drainage preventing layer to prevent the influence of capillary water rising on the roadbed.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The highway immersed roadbed treatment method is characterized by comprising the following steps of:

step 3, laying geotextile water-proof and drainage treatment;

step 4, reinforcing the roadbed soil at the upper part of the roadbed, wherein the upper layer and the lower layer are divided according to different use requirements when in treatment, and the mixing amount of the curing material in the curing soil at the upper layer is larger than that in the curing soil at the lower layer;

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

the preparation method of the curing material comprises the following steps:

a. dehydrating carbide slag to below 10%;

2. The method of treating a highway subgrade as claimed in claim 1, wherein said subgrade is formed into a high-middle and low-side arch after additional soil is applied in step 2.

3. The method for treating a highway subgrade according to claim 1, wherein the clear surface in step 1 is not less than 30cm in thickness.

4. The method for treating a highway subgrade according to claim 1, wherein said step 2 is characterized by additionally spreading 30 cm-50 cm of solidified soil.

5. The method for treating a highway subgrade according to claim 1, wherein the foundation soil is solidified in the range of 40cm to 60cm above the roadbed, and the upper and lower layers are 20cm to 30cm each.

6. The method for treating a highway subgrade as claimed in claim 1, wherein the amount of said solidified material in said upper layer of solidified soil is 8-10 parts per 100 parts of said powdered clay, and the amount of said solidified material in said lower layer of solidified soil is 6-8 parts per 100 parts of said powdered clay.

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 fly ash and 0.5-2 parts of desulfurization alkaline residue;

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

a. dehydrating carbide slag to below 10%;

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

9. The soil solidifying material according to claim 7, wherein the durability of the solidified soil is tested by an indoor test, 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.