Papers by Keyword: Expansive Clay

Abstract: Weathering effects, expansive pressure and pore water pressure are investigated to evaluate their effect on expansive clay slope stability. In particular, the effect of expansive pressure is analyzed to consider its effect on the stability of surface layer of the slope. In this paper, the distribution of expansive pressure in a slope is evaluated and used to analyze the stability of the surface layer of a clay slope. The proposed analysis method is applied in the third ring road project in Chengdu, China, where there are expansive clay slopes. Reasonable results are achieved.

Abstract: The research program developed by the authors and presented in this paper designate the Bahlui clay Romania fitting the clays with specific behaviour such as the Addis Ababa clay, London clay, Dharwad clay, New Yorkshire clay, Ankara clay and Weald clay. Its behaviour is mainly characterized by high swells and shrinkages at moisture variations. The utilization of the Bahlui clay as good foundation soil or material for compacted soil cushion required the determination of the parameters characterizing its behaviour during moisture variation: swell-shrinkage, compressibility and respectively shear strength. The research experiments to define the physical and mechanical behaviour of the Bahlui clay were performed on both natural and remoulded samples with 2.5÷10% mix from the dry soil mass with Portland with/or eco-cement. The paper presents graphs and tables displaying the Portland/eco-cement stabilization influence on the main physical and mechanical indices characterizing the Bahlui clay behaviour during moisture variations as well as conclusions its usage.

Abstract: In order to study dynamic properties of lime-treated expansive clay, a comprehensive series of laboratory tests were conducted via dynamic triaxial test system. The influences of factors such as moisture content, confining pressure, vibration frequency, consolidation ratio and the number of cycles on dynamic characteristics were discussed. It is found that the dynamic stress-strain curves of lime-treated expansive clay show the general trend of hyperbola. Compared with the remoulded expansive soil, the bearing capacity of lime improved expansive soil is higher than remolded soil.

Abstract: Guangxi province is the typical expansive soil area, and the unconfined compressive strength is the important strength index. There is little studied result about the unconfined compressive strength of expansive soil in Guangxi province. Based on the expansive clay experimental embankment of Nanyou Highway, the experimental research on the unconfined compressive strength was undertaken. Tests results indicate that the expansive clay samples are all disintegrated when the sample is dip in water, which show that the stability of expansive clay is very weak. Some lime improving samples of curling 7 days and 14 days are also disintegrated when dipping in water, which indicate that the unconfined compressive strength sample of lime improving expansive clay should curl 28 days. Lime ratio and curing time both influence the unconfined compressive strength of improving expansive clay greatly. There is optimum adding lime ratio for lime improving expansive clay. During the early days of curing the unconfined compressive strength have linear increase with curing time.