静动力荷载作用下路基粗粒料力学特性试验研究  

Experimental study on mechanical characteristics of coarse-grained materials of subgrade under static-dynamic loading

作　　者：杨峰 王伟斌 谢志伟 马一跃 吕玺琳[2] YANG Feng;WANG Weibing;XIE Zhiwei;MA Yiyue;LÜ Xilin(Zhejiang Jiaogong Group Co.,Ltd.,Hangzhou 310052,China;Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China)

机构地区：[1]浙江交工集团股份有限公司,浙江杭州310052 [2]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《岩土工程学报》2023年第S02期247-252,共6页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(U1433123);广西重点研发计划项目(AB22080032)。

摘　　要：粗粒土因其良好的力学性能被广泛应用于路基建设中,但长期荷载作用下填料的变形严重影响了道路结构的安全运营。为了揭示典型路基应力水平及交通荷载条件下粗粒土的变形及强度演化,开展了一系列粗粒土填料静动力学特性试验,并进一步分析了静动力作用下填料破碎特征及差异。研究表明,低围压情况下,较小的轴向应变就可以使材料达到峰值应力状态,且围压的增加可显著提升填料峰值强度。不同围压下,填料在剪切过程中均出现剪胀现象,其中围压小于300 kPa试样的最终体应变均大于0。在动力试验中,填料轴向累积应变在相同加载次数下随着动偏应力的增加而增大,随围压的增加而减小,且前500次加载所造成的轴向应变占总应变的80%。静动力作用下的填料颗粒破碎形式存在差异,静荷载作用下的颗粒破碎主要以边角及整体断裂为主,而动荷载下主要以表面研磨和边角轻微断裂为主。The coarse-grained soil is widely used as the filling materials in subgrade construction due to its excellent mechanical properties.However,the significant deformation of the filling materials caused by long-term loading severely impacts the safe operation of the roadbed structures.In order to reveal the deformation and strength evolution of the coarse-grained soil under typical subgrade stress levels and traffic loading conditions,a series of static-dynamic characteristic tests on the coarse-grained soil are conducted.Furthermore,an in-depth analysis is performed on the differences in the breakage characteristics under static-dynamic loading.The research indicates that under low confining pressure,a smaller axial strain can reach the peak stress state,and the increase in the confining pressure can significantly enhance the peak strength of the filling materials.Under different confining pressures,the fill materials exhibit shear expansion during the shearing process,with the final volumetric strain of samples under the confining pressures less than 300 kPa all exceeding 0.In the dynamic tests,the axial accumulation of the filling materials increases with the dynamic deviator stress,decreases with the confining pressure under the same load cycles,and the axial strain generated by the first 500 loading cycles constitutes 80%of the total strain.The particle breakage pattern in the filling materials under static and dynamic loading differs significantly.Under static loading,the particle breakage primarily occurs in the form of edge fractures and overall rupture.Conversely,under dynamic loading,it predominantly involves surface abrasion and slight edge fractures.

关 键 词：粗粒土填料 应力应变关系 循环响应 累积沉降 颗粒破碎 

分 类 号：TU411[建筑科学—岩土工程] TU441[建筑科学—土工工程]