Processes and mechanisms of multi-collapse of loess roads in seasonally frozen ground regions: A review  

作　　者：GuoYu Li Wei Ma Fei Wang YanHu Mu YunCheng Mao Xin Hou Hui Bing 

机构地区：[1]State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences [2]University of Chinese Academy of Sciences [3]Communication Research Institute of Gansu Province

出　　处：《Research in Cold and Arid Regions》2015年第4期456-468,共13页寒旱区科学（英文版）

基　　金：supported by the National Key Basic Research Program of China (973 Program) (No. 2012CB026106);the Science and Technology Major Project of Gansu Province (No. 143GKDA007);the West Light Foundation of CAS for Dr. G. Y. Li;the Program for Innovative Research Group of the Natural Science Foundation of China (No. 41121061);the Foundation of the State Key Laboratory of Frozen Soils Engineering of CAS (No. SKLFSE-ZT-11)

摘　　要：Usually, the collapsible loess widely distributed across the world can serve as a type of foundation soil that meets its strength requirement after dense compaction and elimination of collapsibility. However, many problems such as cracks and differential settlement still occur in loess roads in the seasonally frozen ground regions after several years of op- eration. Many studies have demonstrated that these secondary or multiple collapses primarily result from the repeated freezing-thawing, wetting-drying, and salinization-desalinization cycles. Therefore, we conducted a research program to （1） monitor the in-situ ground temperatures and water content in certain loess roads to understand their changes, （2） study the effects of freezing-thawing, wetting-drying, and salinization-desalinization cycles on geotechnical properties and micro-fabrics of compacted loess in the laboratory, and （3） develop mitigative measures and examine their engineered effectiveness, i.e., their thermal insulating and water-proofing effects in field and laboratory tests. Our results and advances are reviewed and some further research needs are proposed. These findings more clearly explain the processes and mechanisms of secondary and multiple collapse of loess roads. We also offer references for further study of the weakening mechanisms of similar structural soils.Usually, the collapsible loess widely distributed across the world can serve as a type of foundation soil that meets its strength requirement after dense compaction and elimination of collapsibility. However, many problems such as cracks and differential settlement still occur in loess roads in the seasonally frozen ground regions after several years of op- eration. Many studies have demonstrated that these secondary or multiple collapses primarily result from the repeated freezing-thawing, wetting-drying, and salinization-desalinization cycles. Therefore, we conducted a research program to （1） monitor the in-situ ground temperatures and water content in certain loess roads to understand their changes, （2） study the effects of freezing-thawing, wetting-drying, and salinization-desalinization cycles on geotechnical properties and micro-fabrics of compacted loess in the laboratory, and （3） develop mitigative measures and examine their engineered effectiveness, i.e., their thermal insulating and water-proofing effects in field and laboratory tests. Our results and advances are reviewed and some further research needs are proposed. These findings more clearly explain the processes and mechanisms of secondary and multiple collapse of loess roads. We also offer references for further study of the weakening mechanisms of similar structural soils.

关 键 词：mechanics of loess loess roads secondary or multiple collapse FREEZING-THAWING wetting-drying saliniza-tion-desalinization 

分 类 号：U416.16[交通运输工程—道路与铁道工程]