漳州平原变性土胀缩特性研究

Shrinking and Swelling Characteristics of Vertisols in Zhangzhou Plain

漳州平原的干湿季气候会引起变性土含水率的变化,导致土体发生胀缩效应。研究胀缩的本质规律有重要意义。研究从剖面形态、颗粒组成及水分物理性质等方面,系统地揭示了该区变性土的胀缩特征。该类土壤剖面均一,质地黏细,线性膨胀系数大于0.08。土壤膨胀收缩性能强,土表易生网状裂隙。在此基础上,以变性原状土及其扰动土为研究对象,进行了胀缩性能的对比试验,结果表明,土样经过一个胀缩过程后,土样的高度有所增加,质地越黏细,胀缩性越大;扰动土的膨胀量及收缩量均大于原状土。最后提出工程管理建议,为类似土壤分布区提供参考。

The climatic zone is characterized by alternate wet and dry seasons in Zhangzhou Plain. The vertisols experience periodic swelling and shrinkage during alternate wet and dry seasons. The study is therefore very significant for revealing the law of swelling and shrinkage, and plays an important role in engineering practice in similar region. The morphology, particle content and physical properties of vertisols distributed are elucidated in the paper in terms of the different landform and land use. The soil profile is uniform. Associated with the swelling and shrinkage of the soil, cracks were usually observed at the soil surface. In addition, to study both undisturbed and disturbed, the contrast experiments on swelling-shrinkage behaviors were conducted. The test results showed that after each cycle, the height of the soil sampled increased, which indicates that the swell-shrink behavior of vertisols are not completely reversible. The swellingshrinking characteristics of soils became greater with stickier texture. Compared to disturbed soils, the shrinking of undisturbed soils and the relative swelling was smaller. Finally engineering management suggestions were proposed which can provide reference for similar soil distribution area.