巴东组泥岩重塑土湿胀特性宏细观跨尺度研究  

Macro-microscopical Cross-scale Study on Moisture Swelling Characteristics of Mudstone Remodeled Soil in Badong Formation

作　　者：赵二平[1] 张聪 章涵 李森 蒋尚家 车德龙 ZHAO Erping;ZHANG Cong;ZHANG Han;LI Sen;JIANG Shangjia;CHE Delong(Hubei Key Laboratory of Disaster Prevention and Mitigation,China Three Gorges University,Yichang Hubei 443002,China;School of Environmental Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]三峡大学防灾减灾湖北省重点实验室,湖北宜昌443002 [2]华中科技大学环境科学与工程学院,武汉430074

出　　处：《铁道建筑》2024年第7期143-148,共6页Railway Engineering

基　　金：国家自然科学基金高铁联合基金(U2034203);国家自然科学基金青年基金(42207218)。

摘　　要：针对泥岩地区高速铁路路基上拱问题,以郑万高速铁路沿线巴东组泥岩风化土为研究对象,开展不同初始含水率、干密度、上覆荷载及干湿循环次数条件下泥岩重塑土湿胀特性宏细观试验。基于多因素从宏细观角度对泥岩膨胀性进行了试验验证,对维护膨胀土区域工程稳定性有一定借鉴作用。结果表明:泥岩重塑土无荷膨胀率随着初始含水率的增加线性减小,随着初始干密度的增加呈指数增长;上覆荷载作用抑制了泥岩重塑土的膨胀变形;干湿循环作用下,泥岩重塑土膨胀率及吸水量均随干湿循环次数的增多而总体上先增加后减小,强度劣化,泥岩内部结构由致密变为疏松,矿物颗粒吸水膨胀,试样内部大尺寸孔隙逐渐形成。In response to the problem of swelling on high-speed railway subgrade in mudstone areas,macro and micro experiments were conducted on the wet swelling characteristics of mudstone remolded soil under different initial moisture content,dry density,overlying load,and wet-dry cycle times,using weathered mudstone soil from the Badong Formation along the Zheng-Wan high speed railway as the research object.Based on multiple factors and macro and micro perspectives,experimental verification was conducted on the expansive properties of mudstone,which has a certain reference value for maintaining the engineering stability of expansive soil areas.The results show that the unloaded expansion rate of mudstone remolded soil decreases linearly with the increase of initial moisture content,and increases exponentially with the increase of initial dry density.The overlying load suppresses the expansion deformation of mudstone remolded soil.Under the action of wet-dry cycles,the expansion rate and water absorption of remolded mudstone soil generally increase and then decrease with the increase of wet-dry cycles,leading to strength degradation.The internal structure of mudstone changes from dense to loose,and the mineral particles absorb water and expand,then the large-sized pores gradually form inside the sample.

关 键 词：高速铁路路基 泥岩 重塑土 干湿循环 湿胀特性 分形维数 

分 类 号：U213.14[交通运输工程—道路与铁道工程]