CN114197444A - Method for improving expansive soil - Google Patents
Method for improving expansive soil Download PDFInfo
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- CN114197444A CN114197444A CN202111587480.2A CN202111587480A CN114197444A CN 114197444 A CN114197444 A CN 114197444A CN 202111587480 A CN202111587480 A CN 202111587480A CN 114197444 A CN114197444 A CN 114197444A
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- soil
- expansive soil
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
- E02D3/12—Consolidating by placing solidifying or pore-filling substances in the soil
-
- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
- E01C3/00—Foundations for pavings
- E01C3/04—Foundations produced by soil stabilisation
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
- E02D3/005—Soil-conditioning by mixing with fibrous materials, filaments, open mesh or the like
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- Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Civil Engineering (AREA)
- Environmental & Geological Engineering (AREA)
- Soil Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Paleontology (AREA)
- Agronomy & Crop Science (AREA)
- General Engineering & Computer Science (AREA)
- Architecture (AREA)
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
Abstract
The invention discloses an expansive soil improvement method, which belongs to the technical field of roadbed and pavement engineering, and is characterized in that the expansive soil is treated in engineering construction in areas where the expansive soil is widely distributed, so that the harm of the expansive soil to the engineering is reduced to a range acceptable by the engineering, and based on the consideration of reducing the influence on the surrounding environment and saving the cost, the expansive soil physical improvement method is provided: namely, sisal fiber and silty soil in a yellow flood area are used for improving weak expansive soil, and the specific process is as follows: (1) pretreating the material, namely selecting the required expansive soil, silt soil and sisal fiber according to the mass ratio, and drying the expansive soil, the silt soil and the expansive soil respectively for later use, wherein the doping amount of the silt soil accounts for 10-50% of the total mass of the silt soil and the expansive soil, and the doping amount of the sisal fiber accounts for 0.1-0.5% of the total mass of the silt soil and the expansive soil; (2) uniformly mixing the materials in the step (1) in a mixing container; (3) and (3) carrying out material sealing treatment on the mixture in the step (2) to obtain the material.
Description
Technical Field
The invention belongs to the technical field of roadbed and pavement engineering, and particularly relates to an improvement method of expansive soil.
Technical Field
With the continuous strength of Chinese national force, the construction of roads in China changes greatly. The tripod force pulsation of the transportation industry makes remarkable contribution to the development of national economy, the improvement of travel conditions and the great improvement of the living standard of residents in China all over the country. However, China is also one of the countries in which expansive soil is widely distributed, and the expansive soil mainly contains mineral components such as montmorillonite and illite and is distributed in different degrees in a plurality of provinces and cities in China. Has strong characteristics of water swelling and water loss shrinkage, so that a search is needed for solving the problem of the harm of the weak swelling soil.
In the existing improvement of expansive soil, the chemical improvement can cause difficulty in mixing in construction, environmental pollution and cost increase, and is contrary to the current green traffic policy of China. In addition, in the yellow river basin of China, due to continuous scouring and changing for thousands of years, the average sand conveying amount of the yellow river per year reaches 16 hundred million tons, and the yellow river has the properties of looseness, difficult molding and good water absorption. And the sisal fiber has the characteristics of flexible texture, low price, environmental protection and capability of effectively solving the problem of poor caking property caused by the improvement of the expansive soil by the silt.
Aiming at the weak expansive soil in China, the 'green traffic' policy in China is in depth, the expansive soil, the silty soil in the yellow pan area and the sisal fibers are fully used for road engineering construction, the current trend can be well met, resources are fully utilized, the purpose of environmental protection is achieved, and a large amount of funds are saved.
Accordingly, the present invention provides a method for improving expansive soil.
Disclosure of Invention
The application aims to provide an improvement method of expansive soil, so that engineering construction is facilitated, and the problem of engineering caused by poor characteristics of the expansive soil is solved.
The technical scheme adopted by the application is detailed as follows.
The process of improving swelled ground includes the following steps:
(1) pretreating the material, namely selecting the required expansive soil, silt soil and sisal fiber according to the mass ratio, and drying the expansive soil, the silt soil and the expansive soil respectively for later use, wherein the doping amount of the silt soil accounts for 10-50% of the total mass of the silt soil and the expansive soil, and the doping amount of the sisal fiber accounts for 0.1-0.5% of the total mass of the silt soil and the expansive soil;
(2) uniformly mixing the materials in the step (1) in a mixing container;
(3) and (3) carrying out material sealing treatment on the mixture in the step (2) to obtain the material.
Further, the expansive soil is expansive soil with a plasticity index of more than 17 and a free expansion rate of 40-65%.
Furthermore, in the silt, the mass of particles smaller than 0.0075mm accounts for 23% of the total mass of the silt, and the mass of particles of 0.0075 mm-2 mm accounts for more than 70% of the total mass of the silt.
Further, the sisal fibers are 0.25mm in average diameter and 5mm in average length.
Furthermore, the content of the silt and the expansive soil is 30 percent of the total mass of the silt and the expansive soil, and the content of the sisal fiber is 0.3 percent of the total mass of the silt and the expansive soil.
Further, the drying refers to drying at 105 ℃ for 8 hours.
Further, the material sealing treatment is to place the material at normal temperature for 12-24 hours.
The expansive soil obtained by the improved method.
Free expansion rate tests show that the free expansion rate of the dry expansive soil sample is 50.2 percent, the dry expansive soil sample is a weak expansive soil sample, engineering construction requirements are not met, and the expansive soil needs to be treated until the engineering requirements are met. The indoor physical property test shows that the silt soil can effectively improve the bad properties of the expansive soil, and the sisal fiber can improve the caking property of the expansive soil. Greatly reduces the harm of the expansive soil, saves the cost and accelerates the construction efficiency.
In general, compared with the prior art, the invention has the following beneficial effects:
(1) the improved expansive soil has good comprehensive performance, can greatly improve the poor characteristics of weak expansive soil, and reduces the engineering hazard brought by the weak expansive soil.
(2) The improved materials adopted by the invention are silt and sisal fiber in the yellow flood area, and the reserves are rich. And the environment is protected, and the environment is not polluted.
(3) The addition of the sisal fibers can enable the expanded soil bodies to be mutually tied after improvement, so that a stable net structure is formed, the soil bodies are reinforced, and the cohesiveness of the improved soil is improved.
(4) The method can more scientifically utilize the silty soil in the yellow pan area, the sisal fiber and the expansive soil mixture, is simple to operate and saves the fund.
Detailed Description
The present application is further illustrated by the following examples, which are intended to briefly describe the test materials, test instruments, and other test background conditions in the following examples before describing the specific examples.
Test materials:
expansive soil: the selected expansive soil is brownish red and hard, and a small amount of calcareous nodules and ferro-manganese nodules are mixed in the expansive soil. According to the technical specification of expansive soil region construction (GB 50112-2013), taking a representative air-dried soil sample, passing through a 0.5mm sieve, drying, and then carrying out a free expansion rate test, determining that the free expansion rate of the soil sample is 50.2%, and preliminarily judging that the selected soil sample is weak expansive soil and cannot be directly applied to road engineering construction. The basic mechanical indexes of the expansive soil used in the test are as follows:
TABLE 1 basic mechanical index of expansive soil used
Silt soil: the used silt is taken from a yellow flood area at the northern coast of the yellow river, the reserve is rich, three soil samples are selected according to road soil engineering test regulation (JTG E40-2007), and an indoor compaction test is carried out on the silt, and the screening data of the silt is as follows:
TABLE 2 screening data for silt
Sisal fiber: the used sisal fiber has flexible texture, low cost and environmental protection. The basic physical indexes of the sisal fibers are as follows:
TABLE 3 basic physical Properties of sisal fibers
The test instrument:
screening instruments, free expansion rate measuring instruments, compaction instruments, demolding instruments, consolidation instruments, expansion instruments and some instruments and equipment commonly used in laboratories.
Example 1
(1) And (3) pretreating the materials, namely selecting the required weak expansive soil and silt soil according to the mass ratio, and respectively pretreating for later use. The pretreatment mainly comprises the steps of drying the weak expansive soil and the silt soil, wherein the drying refers to the step that the expansive soil and the silt soil need to be put into an oven to be dried for 8 hours at 105 ℃;
(2) and (2) mixing the materials in the step (1) in a mixing container (such as a mixing pot) to uniformly mix the materials.
(3) And (3) placing the mixture obtained in the step (2) at normal temperature for 12-24 hours for material sealing treatment (so as to uniformly distribute water in the soil sample). And finally, performing application.
The mixing amount of the expansive soil and the silt is respectively proportioned according to the mixing amount of 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50 by mass ratio.
The change of the free expansion rate can reflect the improvement effect of the improved expansive soil, according to the highway soil engineering test regulation (JTG E40-2007), the free expansion rate of the improved expansive soil under different doping rates is obtained by passing a free expansion rate test soil sample through a 0.05mm sieve according to different doping rates of silt, and the free expansion rate of the improved expansive soil under different doping rates is as follows:
TABLE 4 free expansion rate of expansive soil under different sand-doped ratio
The indoor test obtains the expansive force of each mixing amount, according to the requirement of highway geotechnical test regulation (JTG E40-2007), a WG type single-lever consolidation apparatus is adopted as a test instrument, and the expansive force of expansive soil under different sand mixing ratios is as follows:
TABLE 5 expansive force of expansive soil under different sand-mixing ratio
The compression coefficient and the compression modulus of each mixing amount are obtained through indoor tests, according to highway soil engineering test regulation (JTG E40-2007), a test instrument mainly adopts WG type, and test data obtained through consolidation tests are as follows:
TABLE 6 consolidation test data of expansive soil under different sand-doping ratios
Through analysis, the silt soil has obvious effect of reducing the expansion potential of the dry expansive soil, and can improve the hydrophilic characteristic of the expansive soil, and when the sand doping proportion is 30%, the maximum dry density is 1.865g/cm3Meanwhile, the silt can improve the expansion characteristic and the consolidation characteristic of the expansive soil. Meanwhile, referring to the influence of the free expansion rate, the free expansion rate of the improved soil under the condition of 20 percent of silt doping amount is 39.6 percent, according to the regulation of highway soil engineering test regulation (JTG E40-2007), the expansion rate of the improved soil and the limit of the improved soil close to weak expansion soil are considered, and the factors of uneven distribution of the expansion soil, poor control of construction engineering quality and the like are considered, so that the engineering quality problem is easily caused. The free expansion rate of the improved soil is 33.5% under the condition of 30% of silt content, and the engineering construction requirement is met.
Example 2
(1) And (3) pretreating the materials, namely selecting the required weak expansive soil, silt soil and sisal fibers according to the mass ratio, and respectively pretreating for later use. The pretreatment is mainly to dry the weak expansive soil, the silty soil and the sisal fibers, wherein the drying refers to that the expansive soil, the silty soil and the sisal fibers are put into an oven to be dried for 8 hours at 105 ℃, and the mass ratio of the silty soil is fixed to be 30% of the optimal mixing amount.
(2) And (2) mixing the materials in the step (1) in a mixing container (such as a mixing pot) to uniformly mix the materials.
(3) And (3) placing the mixture obtained in the step (2) at normal temperature for 12-24 hours for material sealing treatment. And finally, performing application.
Wherein, the blending amount of the sisal fiber is respectively proportioned according to the blending amount of 0%, 0.1%, 0.3% and 0.5% of the total mass of the silt and the expansive soil.
The change of the free expansion rate can reflect the improvement effect of the improved soil expansive soil, and according to the highway soil engineering test regulation (JTG E40-2007), the free expansion rate of the improved expansive soil under different blending amounts of sisal fibers is obtained through tests as follows:
TABLE 7. free swell ratio of improved expansive soil with different blending amount of sisal fiber
The expansive force of each mixing amount is obtained through indoor tests, according to the requirements of highway soil engineering test regulation (JTG E40-2007), a WG type single-lever consolidation apparatus is adopted as a test instrument, and the expansive force of the improved expansive soil under different mixing amounts of sisal fibers is obtained through tests as follows:
TABLE 8 expansibility of improved expansive soil with different blending amount of sisal fiber
The compression coefficient and the compression modulus of each mixing amount are obtained through indoor tests, according to highway soil engineering test regulation (JTG E40-2007), a test instrument mainly adopts WG type, and consolidation test data of the improved expansive soil under different mixing amounts of sisal fibers are obtained through tests as follows:
TABLE 9 consolidation test data for improved bentonite with different sisal fiber loadings
According to analysis, under the condition that the optimum mixing amount of silt is 30%, the sisal fibers can reduce the free expansion rate and the expansibility, and when the mixing amount of the sisal fibers is 0.3%, the free expansion rate and the expansibility reach the minimum value; and with the increase of the addition amount of the sisal fibers, the compression modulus and the compression coefficient are not obviously changed, which shows that the sisal fibers have no great influence on the consolidation of the soil body.
Combining the examples 1 and 2, the optimum amounts of silt and sisal fibers were determined to be 30% and 0.3%, respectively. The effect of improving the expansive soil is the best.
Combining the above results, the following conclusions can be briefly concluded:
(1) the improved expansive soil has good comprehensive performance, can greatly improve the poor characteristics of weak expansive soil, and reduces the engineering hazard brought by the weak expansive soil.
(2) The improved materials adopted by the invention are silt and sisal fiber in the yellow flood area, and the reserves are rich. And the environment is protected, and the environment is not polluted.
(3) The addition of the sisal fibers can enable the expanded soil bodies to be mutually tied after improvement, so that a stable net structure is formed, the soil bodies are reinforced, and the cohesiveness of the improved soil is improved.
(4) The method can more scientifically utilize the silty soil in the yellow pan area, the sisal fiber and the expansive soil mixture, is simple to operate and saves the fund.
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 (8)
1. The method for improving the expansive soil is characterized by comprising the following steps of:
(1) pretreating the material, namely selecting the required expansive soil, silt soil and sisal fiber according to the mass ratio, and drying the expansive soil, the silt soil and the expansive soil respectively for later use, wherein the doping amount of the silt soil accounts for 10-50% of the total mass of the silt soil and the expansive soil, and the doping amount of the sisal fiber accounts for 0.1-0.5% of the total mass of the silt soil and the expansive soil;
(2) uniformly mixing the materials in the step (1) in a mixing container;
(3) and (3) carrying out material sealing treatment on the mixture in the step (2) to obtain the material.
2. The method for improving expansive soil according to claim 1, wherein the expansive soil has a plasticity index of more than 17 and a free expansion rate of 40-65%.
3. The method for improving expansive soil according to claim 1, wherein in the silt, the mass of particles smaller than 0.0075mm accounts for 23% of the total mass of the silt, and the mass of particles 0.0075mm to 2mm accounts for 70% or more of the total mass of the silt.
4. The method for improving expansive soil of claim 1, wherein said sisal fibers have an average diameter of 0.25mm and an average length of 5 mm.
5. The method for improving expansive soil according to claim 1, wherein the content of the silt is 30% and the content of the sisal fiber is 0.3% of the total mass of the silt and the expansive soil.
6. The method for improving expansive soil according to claim 1, wherein the drying is drying at 105 ℃ for 8 hours.
7. The method for improving expansive soil according to claim 1, wherein the material-sealing treatment is performed by standing at room temperature for 12-24 h.
8. An expansive soil obtainable by the improved process of claims 1 to 7.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2021113190485 | 2021-11-09 | ||
| CN202111319048 | 2021-11-09 |
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| CN114197444A true CN114197444A (en) | 2022-03-18 |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4790691A (en) * | 1986-10-03 | 1988-12-13 | Freed W Wayne | Fiber reinforced soil and method |
| CN112577801A (en) * | 2020-12-24 | 2021-03-30 | 浙江大学 | Device and method for preparing physicochemical method improved soil sample containing directionally distributed fibers |
-
2021
- 2021-12-23 CN CN202111587480.2A patent/CN114197444A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4790691A (en) * | 1986-10-03 | 1988-12-13 | Freed W Wayne | Fiber reinforced soil and method |
| CN112577801A (en) * | 2020-12-24 | 2021-03-30 | 浙江大学 | Device and method for preparing physicochemical method improved soil sample containing directionally distributed fibers |
Non-Patent Citations (9)
| Title |
|---|
| 兰小威等: "剑麻纤维加固黏土抗压强度与变形规律研究", 《工程勘察》 * |
| 兰小威等: "剑麻纤维加固黏土抗压强度与变形规律研究", 《工程勘察》, no. 5, 31 May 2021 (2021-05-31), pages 1 - 5 * |
| 庄心善等: "玄武岩纤维改良膨胀土的试验研究", 《湖北工业大学学报》, vol. 31, no. 2, pages 89 - 92 * |
| 庄心善等: "粉煤灰—玄武岩纤维改良膨胀土试验研究", 《公路工程》 * |
| 庄心善等: "粉煤灰—玄武岩纤维改良膨胀土试验研究", 《公路工程》, vol. 41, no. 3, 30 June 2016 (2016-06-30), pages 1 - 4 * |
| 王冰: "膨胀土纤维加筋的强度特性实验研究", 《安徽建筑》 * |
| 王冰: "膨胀土纤维加筋的强度特性实验研究", 《安徽建筑》, no. 2, 29 February 2020 (2020-02-29), pages 193 - 195 * |
| 王欢等: "粉砂土改良弱膨胀土工程特性研究", 《河南大学学报（自然科学版）》, vol. 51, no. 1, 31 January 2021 (2021-01-31), pages 109 - 115 * |
| 王欢等: "粉砂土改良弱膨胀土工程特性研究", 《河南大学学报（自然科学版）》, vol. 51, no. 1, pages 109 - 115 * |
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