摘要
为明确模块面板式加筋土路基在顶面循环荷载作用下的受力变形规律与机制,以延安市某加筋土路基工程为背景,开展动三轴试验,关注不同荷载强度下试样动应力、动应变等多项指标的演化趋势,同时搭建加筋土路基数值模型并完成计算,明确路基水平沉降与面板侧向位移的潜在规律,进而探讨循环荷载作用下加筋土路基工程的动力响应机制。认知如下:在循环荷载的参与下,累积轴向塑性应变随加载次数的增加呈增长趋势,即先快速增大,随后趋缓,最后稳定;塑性应变曲线形态不一,呈“宽胖型”与“陡峻型”并存的态势;Monismith模型和改进Monismith模型均可较好表达累积轴向塑性应变与循环次数的内在联系,但改进Monismith模型更为理想,动应力幅值越大,试样变形稳定所需加载次数越多;路基沉降和面板水平变形随着荷载强度的增加而增大,但所据位置较为稳定,其中峰值路基沉降始终处于载荷外侧处,峰值水平变形则位于0.36~0.43 h区间。
To clarify the law and mechanism of the deformation of the modular panel reinforced soil subgrade under the top surface cyclic load,a dynamic triaxial test was carried out with a reinforced soil subgrade project in Yan’an as the background.The evolution trend of various indicators such as stress,dynamic strain,is investigated.At the same time,a numerical model of reinforced soil roadbed is set up and calculations are performed.The potential laws of horizontal settlement of the roadbed and lateral displacement of the slab are clarified.Response mechanism.The cognition is as follows:With the participation of cyclic loads,the cumulative axial plastic strain increases with the increase of the num-ber of loadings,that is,it increases rapidly first,then slows down,and finally stabilizes.The shape of the plastic strain curve is different,showing the tendency of"broad fat"and"steep"coexisting;both the model and the improved model can better express the internal relationship between the cumulative axial plastic strain and the number of cycles,but the improved model is more ideal.The larger the magnitude of the dynamic stress,the more times the sample needs to be stabilized for deformation.The settlement of the subgrade and the horizontal deformation of the slab increase with the increase of the load intensity,but the location is more stable.The peak subgrade settlement is always outside the load.The peak horizontal deformation is in the range of 0.36h~0.43h.The study provides a useful reference for scientific operation and preventive maintenance of reinforced earth roadbed engineering in mountainous areas.
作者
高海军
董丁明
赵琪
叶万军
景宏君
董琪
GAO Haijun;DONG Dingming;ZHAO Qi;YE Wanjun;JING Hongjun;DONG Qi(Yan'an Highway Administration Bureau of Shaanxi,Yan'an 716000,China;College of Civil and Architectural Engineering,Xi'an University of Science and Technology,Xi'an 710054,China;Road Engineering Research Center of Xi'an University of Science and Technology,Xi'an 710054,China;Shaanxi Science&Technology Holding Group Co.,Ltd.,Xi'an 710003,China)
出处
《防灾减灾工程学报》
CSCD
北大核心
2022年第1期208-215,230,共9页
Journal of Disaster Prevention and Mitigation Engineering
基金
陕西省延安公路管理局项目(2017-16k)
国家自然科学基金项目(41672305)资助。
