Dynamic shear modulus characteristics of expansive soil with different moisture contents and determination method of in situ G- γ decay curve
LI Tianguo1,2， KONG Lingwei1,2, SHU Rongjun1,2
1. State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China;
2. School of Engineering Science, University of Chinese Academy of Sciences, Beijing 100049, China
Abstract：Considering the particularity of the interaction of expansive soil and water , and the fact that the water content of expansive soil is changing in the actual project, the laboratory resonant column tests (RCT)of expansive soil with different water contents were carried out. Meanwhile, combined with in-situ seismic dilatometer tests (SDMT). The results showed that water content have significant effects on the shear modulus of expansive soils, the shear modulus G decreases as the increase of water content ; The influence of the volume change of expansive soil caused by the change of water content on the maximum dynamic shear modulus Gmax was classified as the effect of water contents, a Gmax prediction model for the expansive soil with different water contents was proposed has a good prediction of Jiamusi expansive soil. The maximum dynamic shear modulus Gmax in good linearity with the reference shear strain γr at the same water content, based on this law, an improved method for calculating the in-situ G-γ decay curve of expansive soil was proposed, the improved curve is close to the unmodified curve in the initial stage and is consistent with the field seismic velocity test results; it is found that the improved curve has a smaller attenuation rate and a better suitability in the stiffness analysis of expansive soil, the improved method can help to select the laboratory reference curve reasonably and accurately predict the attenuation law of in-situ dynamic shear modulus.
李甜果1,2，孔令伟1，2，舒荣军1,2. 不同含水率膨胀土动剪切模量特征与原位G-γ衰减曲线确定方法[J]. 振动与冲击, 2021, 40(23): 91-99.
LI Tianguo1,2， KONG Lingwei1,2, SHU Rongjun1,2. Dynamic shear modulus characteristics of expansive soil with different moisture contents and determination method of in situ G- γ decay curve. JOURNAL OF VIBRATION AND SHOCK, 2021, 40(23): 91-99.
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