Authors: XING Yi-chuan 1, WANG Jun-chen 2, HUANG Qing-wen 3
1. China Institute of Water Resources and Hydropower Research, Beijing 100038, China
2. Hydropower Design Institute of Jilin Province, Changchun 130500, China
3. Water Conservancy Bureau of Xinjiang Turpan Region, Turpan 838000, China
Abstract: In order to rehabilitate the damaged karezs and to prevent this kind of project from destruction, the laws of the strength and deformation of saturated and unsaturated loess under freeze-thaw and non-freeze-thaw conditions were studied by on-site investigation and combining with the triaxial compression tests, the isotropic compression tests and the elastic module tests to find out the failure mechanism. In the mean time, the failure characteristics of the shafts and culverts of the karezs were numerically simulated by using elasto-plastic finite element method. Based on these studies, the karez failure mechanism was revealed. Following the changing of season the temperature and humidity in karezs varied cyclically in a year, the soil structure experienced the frost heave in winter and the side walls of culverts subjected to the increases of deformation and plastic strain during melting as temperature rose. Under this cyclic action, the damaged area in the shafts and at the lower parts of the side walls occurred and gradually flakes away as the plastic area expanded, which finally resulted in failure. The measures for preventing from failure are also proposed.
Key words: Karez, loess mechanical tests, numerical analysis, damage mechanism
Published in: Journal of Hydraulic Engineering, Vol.42, No.5, 2011
Article ID: 0559-9350 (2011) 05-0529-08
