Studies on parallel seismic testing for integrity of cemented soil columns

• Published in: Journal of Zhejiang University. A. Science Vol. 8; no. 11; pp. 1746 - 1753
• Main Authors: Huang, Da-zhi, Chen, Long-zhu
• Format: Journal Article
• Language: English
• Published: Institute of Engineering Safety and Disaster Prevention, Dept. of Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, China 01.10.2007
• Subjects: 平行地震测试; 数字模拟; 整体性测试; 水泥柱; Parallel seismic (PS) testing; Cemented soil columns; Numerical simulation; Integrity testing
• ISSN: 1673-565X; 1862-1775
• DOI: 10.1631/jzus.2007.A1746

The principle and process of parallel seismic （PS） testing for the integrity testing of cemented soil columns are introduced in this paper. A three-dimensional （3D） finite element model （FEM） for the pile-soil system is established for impulse responses. Under saturated soil or unsaturated soil condition, several vibrating velocity-time histories at different depths in parallel hole are obtained based on the numerical simulation. It shows that the length of the pile and the one-dimensional （1D） P-wave velocity in the pile can be determined easily from the features of the mentioned velocity-time histories. By examining the slopes of the first arrival time plotted versus depth or the depth where the amplitude of the first arrival significantly decreases, the length of the pile can be determined. The effects of the 3D P-wave propagation through the saturated soil and the defect of the cemented soil column on the velocity-time histories are also investigated.