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Mixing Technique and Compaction Characteristics of Lime-improved Dispersive Soil
HE Jian-xin, GAO Peng-zhan, YANG Hai-hua, YANG Wei, WEN Jun, GENG Xu, WANG Ning-yuan
Journal of Changjiang River Scientific Research Institute ›› 2025, Vol. 42 ›› Issue (3) : 118-124.
PDF(5476 KB)
PDF(5476 KB)
Mixing Technique and Compaction Characteristics of Lime-improved Dispersive Soil
The soil used for the core dam of a reservoir in Xinjiang is dispersive soil. To treat this soil, 1% lime is added. To ensure project quality and achieve uniform mixing, a ZB05 cold recycling paver was employed, with mixing cycles set at 1, 2, 4, and 6, respectively. The SG-6 multifunctional direct-reading calcium meter was used for rapid and random detection of soil lime content to control the uniformity of the lime-treated soil. The influence of aging time on the compaction characteristics of the improved soil was also investigated. In the field construction environment, the impact of curing age on the physical and mechanical properties of the improved soil was evaluated through indoor compression and direct shear tests. Results show that, when rolled 8 times with a spread thickness of 30 and 35 cm, the settlement of the soil material stabilizes, and the dry density after rolling meets the requirement of ≥1.73 g/cm3, with a compaction degree of ≥99%. When the mixing cycle is 6, the uniformity of the lime mixing stabilizes, with a coefficient of variation ( Cv ) of 0.28. As the aging time increases, the lime-treated soil becomes less favorable for rolling. To maintain a compaction degree of 99%, the aging time should not exceed 9 hours. The compressibility and shear strength of the improved soil are significantly influenced by curing age. As curing age increases, the compressibility of the lime-treated soil decreases, whereas shear strength increases, consistent with laboratory test results.
dispersive soil / rolling process / mixing process / aging time / curing age
| [1] |
汪恩良, 李宇昂, 任志凤, 等. 基于扫描电镜和核磁共振技术的分散性土改良微观结构性变化研究[J]. 岩土工程学报, 2023, 45(6):1123-1132.
(
|
| [2] |
杨小川. 寒冷地区改性分散性土冲刷试验研究[D]. 西安: 西安建筑科技大学, 2019.
(
|
| [3] |
王观平. 分散性粘土与水利工程[M]. 北京: 中国水利水电出版社, 1999.
(
|
| [4] |
刘杰, 杨玉婳, 姚海林, 等. 基于不同改性方法的分散性黏土处治试验研究[J]. 岩土力学, 2020, 41(增刊1):163-170.
(
|
| [5] |
汪涛. 沙旋沟淤地坝筑坝土料的分散性鉴定及改性试验研究[D]. 杨凌: 西北农林科技大学, 2016.
(
|
| [6] |
严应佳, 樊恒辉, 杨秀娟. 粉煤灰改性分散性土的工程特性试验研究[J]. 水力发电学报, 2017, 36(4): 86-94.
(
|
| [7] |
|
| [8] |
李华銮, 高培法, 穆乃敏, 等. 分散性土的鉴别及改性试验[J]. 山东大学学报(工学版), 2010, 40(4):92-95.
(
|
| [9] |
邓铭江, 周小兵, 万金平, 等. “635” 水利枢纽大坝心墙防渗土料分散性鉴定及改性试验研究[J]. 岩土工程学报, 2000, 22(6): 673-677.
(
|
| [10] |
陈劲松, 顾缬琴, 盛小涛, 等. 大坝心墙料分散性及处理措施试验研究[J]. 长江科学院院报, 2016, 33(4): 144-150.
分散性黏土是一种特殊土,具有易被水冲蚀的特性。随着国内外土石坝发展迅速,心墙土的选择范围也不断扩大,能否选用分散性黏土作为心墙填料以及分散性黏土在反滤层保护下防渗效果如何,是工程设计中十分关心的问题。针对某水利枢纽2个料场的心墙料取样开展了与分散性有关的试验研究,通过针孔、碎块、孔隙水溶液及双比重计4种室内试验鉴定方法对心墙料的分散性进行判定。对分散性心墙料掺加不同比例的水泥或生石灰进行了改性,并对改性前后的心墙料渗透特性和反滤保护措施效果进行对比研究。试验成果表明料场的部分心墙料具有分散性;2个料场的土料在水泥掺量3%或者生石灰掺量3%~5%的情况下,基本可以消除土料的分散性;经过掺水泥或石灰等方式改性的心墙料比未掺改性材料的心墙料能承受的水力比降更高;在合适的反滤料保护下,分散性黏土能承受较高的水力比降,在裂缝等不利情况下有良好的自愈能力。
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Dispersive clay is a special soil which can be washed out by water easily. With the development of earth and rockfill dam, the range of choosing core material expands correspondingly. Dispersive clay as core material and its seepage-proofing effect under the protection of filters are issues concerned in engineering design. In this research we collected core materials from two stock grounds of a hydro-junction and conducted laboratory tests using pinhole, fragment, pore water solution and double areometers to determine the dispersibility of core material. By mixing different ratios of cement or quick lime, we modified the dispersibility of the core materials and compared their permeability and filter protection effect before and after modification. Results reveal that by mixing 3% of cement or 3%-5% of quick lime we can eliminate the dispersibility of the core materials from the two sites. Moreover, core material modified by cement or quick lime could bear higher hydraulic gradient than non-modified material does. Under the protection of proper filtration material, dispersive clay could bear high gradient, and has good self-healing ability in the presence of fissures.<br/><br/>
|
| [11] |
樊恒辉, 孔令伟, 李洪良, 等. 马家树水库大坝防渗土料分散性判别和改性试验[J]. 岩土力学, 2010, 31(1): 193-198, 222.
(
|
| [12] |
|
| [13] |
马秀媛, 徐又建. 青岛市官路水库分散性粘土工程特性及改性试验研究[J]. 岩土工程学报, 2000, 22(4): 441-444.
(
|
| [14] |
杨小川, 苏安双, 王远明, 等. 分散性土改性效果干湿循环模型试验研究[J]. 水利水电技术, 2019, 50(2): 202-207.
(
|
| [15] |
边加敏, 蒋玲, 王保田. 石灰改良膨胀土路基施工控制参数[J]. 长安大学学报(自然科学版), 2014, 34(2):51-58.
(
|
| [16] |
刘鸣, 程永辉, 童军. 南水北调中线工程膨胀土边坡处理效果及评价[J]. 长江科学院院报, 2016, 33(3):104-110.
为研究膨胀土边坡在膨胀作用下的破坏形式及边坡处理方案,针对不同工况进行了现场模拟试验与监测。系统总结了膨胀土边坡处理的施工技术;从边坡变形、含水率变化2个方面,全面分析了水泥土改性、土工格栅加筋、土工膜封闭、土工袋填筑4个工况的边坡处理效果。结果表明:水泥改性土(换填非膨胀黏性土)处理效果最好;土工格栅加筋主要存在施工工艺较为复杂的问题;土工袋填筑存在压实度难以控制的问题;土工膜封闭主要由于没有压重处理,效果最差。最后总结并提出了膨胀土边坡处理原则。
(
According to the failure mode of expansive soil slope induced by expansion effect and the monitoring result of on-site simulation test, we summarize the techniques of expansive soil slope treatment. Furthermore, we compare and analyse the effectiveness of four treatment measures (cement soil modification, geogrid reinforcement, geomembrane, and geotextile bags filling) by evaluating the slope deformation and the variation of moisture content. Results reveal that cement soil (replacement of non-expansive clayey soil) has the best performance, whereas geogrid reinforcement is featured with complex techniques, and the compaction degree of geotextile bags filling is hard to control. Finally, we put forward the principles of expansive soil slope treatment.
|
| [17] |
罗喆, 周航, 吴涛, 等. 新疆某水库黏土料填筑碾压参数研究[J]. 湖南水利水电, 2023(4):64-66.
(
|
| [18] |
娄中. 浅议膨胀土路基路拌法施工技术的应用[J]. 中国标准化, 2017(6): 185, 187.
(
|
| [19] |
JTG E51—2009, 公路工程无机结合料稳定材料试验规程[S]. 北京: 人民交通出版社, 2009.
(JTG E51—2009, Test Methods of Materials Stabilized with Inorganic Binders for Highway Engineering: Beijing: China Communications Press, 2009. (in Chinese))
|
| [20] |
|
| [21] |
赵红华, 龚壁卫, 赵春吉, 等. 石灰加固膨胀土机理研究综述和展望[J]. 长江科学院院报, 2015, 32(4):65-70.
(
Previous research results on the mechanism of expansive soil stabilized by lime are summarized. It is clear that cation exchange is the first reaction when lime is added into expansive soil, followed by flocculation and agglomeration. These reactions change the soil’s properties quickly. Pozzolanic reaction of lime and soil is a long-term process, which helps increase the strength of expansive clay. Carbonation and crystallization also contributes to the strength increase of expansive soil. Diffusion and cementation are the causes of interior changes in the soil. Microstructure and mineralogy changes are the internal causes of stabilization of expansive soils. Moreover, analysis on the quantitative cation exchange, quantitative microstructure change, and soil suction change of expansive soil during lime treatment would be new research focus. These investigations will further reveal the fundamental mechanism of expansive soil stabilized by lime. The review also indicates that the possible environmental pollution caused by lime stabilization can be ignored.
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| [22] |
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