
科学技术与工程

中国技术经济学会
基于冻融循环作用下寒区路基土特性与力学响应
Characteristics and Mechanical Response of Subgrade Soil in Cold Region Based on Freeze-thaw Cycles
随着寒区铁路网线的迅速发展,铁路路基病害问题频发。为探讨寒区路基土的冻融特性及力学特性,通过实验手段,系统研究不同含水率、冻结温度和冻融循环次数对路基土冻融特性以及力学特性的影响。实验结果表明:随着含水率的增加、冻结温度的降低以及冻融循环次数增加,土样的冻胀率及融沉系数均一直增加。初始含水率越大及冻结温度越高,水分迁移越明显。随着冻融循环次数增加土样上部水分逐渐减少,下部水分逐渐增加。初始含水率为8%、10%、12%、14%时其结冰温度分别为-1.96、-1.89、-2.17、-2.06 ℃,初始含水率为12%时其结冰温度最低。随着含水率增加,其强度变化范围为3.63 ~ 6.15 MPa;随着冻结温度降低,其强度变化范围为3.26 ~ 6.05 MPa;随着冻融循环次数的增加,其强度变化范围为4.49 ~ 3.68 MPa。研究成果对于保障道路工程的稳定性和安全性具有重要意义。
With the rapid development of railway networks in cold regions, frequent subgrade diseases are observed. To investigate the freeze-thaw characteristics and mechanical properties of subgrade soils in cold regions, a series of laboratory tests were conducted. The effects of moisture content, freezing temperature, and freeze-thaw cycles on soil behavior were systematically investigated. The experimental results indicate that the frost heave ratio and thaw settlement coefficient increase consistently with higher moisture content, lower freezing temperatures, and more freeze-thaw cycles. More pronounced moisture migration is observed under conditions of higher initial moisture content and higher freezing temperatures. The upper part of soil samples shows gradual moisture reduction while the lower part exhibits moisture accumulation with increasing freeze-thaw cycles. The freezing temperatures are measured as -1.96,-1.89, -2.17, -2.06 ℃ for initial moisture contents of 8%, 10%, 12%, and 14% respectively, with the lowest freezing temperature occurring at 12% moisture content. The strength variation ranges are determined as 3.63 ~ 6.15 MPa with increasing moisture content, 3.26 ~ 6.05 MPa with decreasing freezing temperatures, and 4.49 ~ 3.68 MPa with increasing freeze-thaw cycles. These findings are considered significant for ensuring the stability and safety of transportation infrastructure in cold regions.
freeze-thaw cycles / cold region / railway / roadbed / mechanical response
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