Structural Characteristic Analysis on Hardfill Dam Based on Model Test Method

摘要

Hardfill dam is a new type of dam,which has a symmetrical trapezoid-shaped cross section and a concrete impervious facing or other impervious facilities in the upstream.The dam is filled up with cemented sand-gravel material called Hardfill,which is inexpensive and low-strength.In order to investigate the structural behavior under normal working conditions and the failure mode and mechanism in the process of overloading of Hardfill dam,and to analysis the advantages and characteristic of the dam structure,and also to promote the development and application of the new dam construction technique,a stress model test and a geo-mechanical model failure test of the typical Hardfill dam were carried out respectively.Results show that the Hardfill dam dam body mainly endured the compressive stress and without obvious stress concentration under the condition of normal water load.Compared with the conventional gravity dam,Hardfill dam has lower stress level and more uniform stress distribution.The failure mode was concluded as dam heel cracked firstly and then dam toe damaged,finally the dam integrally slid along the interface of the dam and foundation under the condition of water load overloading.Meanwhile,the overloading safety factors derived from the geo-mechanical model failure test are as follows: the crack initiation factor K1 ranges from 6.0 to 7.0,the nonlinear deformation factor K2 ranges from 7.5 to 8.5,and the ultimate load factor K3 ranges from 9.0 to 10.0.Analysis showed that the Hardfill dam has good work performance,strong ultimate bearing capacity and big overload coefficient.It is a kind of high-quality dam type.