| With the increase of infrastructure construction in Northeast China,the amount of engineering construction in frozen saline soil area of Daqing City is gradually increasing.Soil dynamic parameters are important basis for seismic safety evaluation and dynamic response analysis and calculation of frozen saline soil engineering site.At present,scholars have little research on dynamic modulus and damping ratio of frozen saline soil.In this paper,GDS dynamic triaxial test method is used to study the dynamic stress,dynamic modulus,modulus ratio and damping ratio of frozen saline soil under four test conditions of negative temperature,freeze-thaw cycles,confining pressure and vibration frequency.The calculation formula and fitting curve of initial dynamic modulus and maximum damping ratio under different influence conditions are proposed.The envelope curve or normalized curve of dynamic modulus ratio and damping ratio are given.The main work is as follows :(1)The main physical properties of saline soil in Daqing area were obtained by measuring water content,density,salt content and boundary water content test.(2)The influence of negative temperature on the dynamic characteristics of frozen saline soil is studied.The calculation formula and fitting curve of temperature correction coefficient for initial dynamic modulus and maximum damping ratio are proposed,and the envelope curves of dynamic modulus ratio and damping ratio are given.The results show that temperature has the most obvious influence on modulus ratio and damping ratio.(3)The influence of freeze-thaw cycles on the dynamic characteristics of frozen saline soil was studied.The correction coefficient formula and fitting curve of initial dynamic modulus and maximum damping ratio of freeze-thaw cycles were proposed.The envelope curves of dynamic modulus ratio and damping ratio were given.The results show that the influence of freeze-thaw cycles on initial dynamic modulus and maximum damping ratio is obvious.(4)The influence of confining pressure on the dynamic characteristics of frozen saline soil is studied,and the envelopes of dynamic modulus ratio and damping ratio are given.The results show that the influence of confining pressure on dynamic modulus is obvious.(5)The influence of initial moisture content on the dynamic characteristics of frozen saline soil is studied,and the normalized curves of dynamic modulus ratio and damping ratio are given.The results show that when the initial moisture content is the optimal moisture content,the influence of dynamic modulus ratio and damping ratio is the largest. |
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