Study on Strength Development Mechanism of Organic Soil in Dianchi Lake, China
Study on Strength Development Mechanism of Organic Soil in Dianchi Lake, China
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DOI：
10.1155/2022/3884337
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发表时间：
2022-11
影响因子：
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通讯作者：
Siyang Huang;Jing Cao;Cheng Kong;Yue Gao;Yunfei Song;Fangyi Liu;Huafeng Sun;Z. Lai;
中科院分区：
文献类型：
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作者：
Siyang Huang;Jing Cao;Cheng Kong;Yue Gao;Yunfei Song;Fangyi Liu;Huafeng Sun;Z. Lai;
昆明市滇池周边地区广泛分布着富含腐殖酸类的有机质土壤。为探讨HG对有机土强度发展的影响，采用在原状粘性土中加入腐植酸（HA）试剂（混合法）和用富里酸（FA）溶液浸泡（浸泡法）的方法模拟有机土。通过无侧限抗压强度试验和扫描电镜试验，分析了HG对土的影响。抗压强度试验表明，HA能显著降低试样的抗压强度，且随着HA试剂含量的增加，抗压强度继续降低。FA可以显著提高样品的UCS，其随着FA溶液的浓度（降低pH值）而继续增加。在各HG条件下，当HA试剂含量小于10%时，FA的浸渍可显著提高样品的UCS，当HA试剂含量大于10%时，UCS的增长率降低。随着浸泡时间的增加，5%HA试样的抗压强度曲线继续增大并逐渐趋于稳定，当HA试剂含量大于5%时，抗压强度曲线先增大后减小。SEM测试表明，加入HA试剂能显著增大孔隙尺寸，改善孔隙间的连通性，减弱土体结构的连通性。FA的浸渍可以减小孔隙尺寸，减弱孔隙之间的连通性，加强样品结构的连接。
The organic soil is widely distributed around Dianchi Lake in Kunming, which is rich in the humic group (HG). In order to explore the effect of HG on the strength development of organic soil, this paper adopts the method of adding humic acid (HA) reagent into the undisturbed cohesive soil (blending method) and soaking it in fulvic acid (FA) solution (steeping method) to simulate the organic soil. Then, the effect of HG on soil is analyzed by the unconfined compressive strength (UCS) and the scanning electron microscope (SEM) tests. The UCS test shows that HA can significantly reduce the UCS of the samples, and it continues to decrease with the increase of the HA reagent content. FA can substantially enhance the UCS of the samples, which continues to increase with the concentration of FA solution (decreasing the pH value). Under each HG condition, the steeping of FA can significantly increase the UCS of the sample when the content of the HA reagent is less than 10%, and the growth rate of the UCS decreases when it is greater than 10%. With the increase of steeping age, the UCS of the 5% HA samples continued to increase and gradually became stable, and when the content of the HA reagent is more than 5%, the UCS curve first increases and then decreases. The SEM test shows that adding HA reagent can significantly increase the pore size, improve the connectivity between the pores, and weaken the connection of the soil structure. The steeping of FA can reduce the pore size, weaken the connectivity between the pores, and strengthen the connection of the sample structure.