Comparative experimental study on static shear strength and postcyclic strength of saturated silty clay
(2.Shandong Institute of Earthquake Engineering, Jinan, Shandong Province, China 250021)
(3.State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao, Shandong Province, China 266590)
(4.China MCC20 Group Corp., Ltd., Shanghai, China 201999)
(5.College of Architecture and Civil Engineering, Wenzhou University, Wenzhou, Zhejiang Province, China 325035)
【Abstract】Based on the widely distributed silty clay in the alluvial basin of the lower Yellow River, the dynamic triaxial apparatus and the strain controlled triaxial apparatus were conducted to investigate the undrained shear strength of the silty clay after vibration under different confining pressures and over-consolidated ratios (OCR). It is shown that the shear behavior of the sample after vibration is similar to that in the over-consolidated state. Compared with the shear behavior before vibration, it can be found that the vibration has little influence on the shear strength when the similar over-consolidated ratio (SOCR) is less than 1.25, while SOCR is higher than 1.25, the shear strength of the sample takes a dive and the failure pore pressure ratio decreases first and then increases. Through the comparison of post-unloading shear strength in different SOCRs and under the same confining pressures, it can be concluded that the shear strength increases with OCR exponentially. The increase in the shear strength caused by SOCR is more obvious than that by OCR. In addition, the shear strength ratio also goes up with the growth of SOCR and OCR. Therefore, the OCR can be adopted to evaluate the foundation strength after dynamic load if it is difficult to carry out the dynamic test in practice.
【Keywords】 silty clay; vibration loading; over-consolidated ratio; similar over-consolidated ratio; pore pressure; shear strength;
(Translated by Hu P)
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