基于路面覆盖效应的强蒸发地区路基湿度预估和强度衰变机理研究

新疆地处干旱半干旱气候区，公路路基中存在着强烈的水汽蒸发。由于路面覆盖效应的影响，阻止了水分的自由蒸发，使得路基内部水分积聚，进而导致路基强度衰变，引起路基病害频发，严重影响到道路的使用性能和耐久性。本课题拟以新疆地区受强水汽蒸发和大昼夜温差气候影响的路基工程为研究背景，通过现场调研、室内试验、理论分析和数值模拟等手段，研究路基土水汽迁移特性和路面覆盖效应下的湿度分布特性。同时分析气候环境和干湿循环对土体基质吸力的影响，建立强蒸发条件下路基水汽迁移的水温耦合方程；分析路面覆盖效应对路基湿度影响的范围，并建立路面覆盖效应下的路基湿度预估模型。在此基础上，采用非饱和土三轴试验、动回弹模量试验，把握路基强度对湿化作用和干湿循环的敏感度，分析路基结构强度衰变机理及其过程，建立路基强度衰变的预估模型，从而为强蒸发地区道路设计提供准确的数据支撑，达到降低路基病害影响提升路基工作性能。

Xinjiang is located in the arid and semi-arid climate zones, and there is a strong water vapor evaporation in highway subgrade. Because of the influence of the pavement blanketing effect, Free water evaporation was prevented，which makes moisture accumulation in the t interior of subgrade，leading to the subgrade structure strength decay, causing frequent subgrade diseases, serious affecting the performance and durability of highway. Puting subgrade engineering in the Xinjiang as research background，the subject research characteristic water vapor evaporation in highway subgrade and characteristics of humidity distribution under the pavement blanketing effect through the field investigation, indoor test and theoretical analysis and numerical simulation methods, analyse the matrix suction of soil affected by the climate and dry-wet circulation，establish water temperature coupling equation of subgrade moisture migration based on strong evaporation conditions，analyse range of influence subgrade humidity and establish subgrade humidity prediction model based on the pavement blanketing effect.On this basis, the subject should master the sensitivity of subgrade strength in wetting effect and dry-wet circulation by unsaturated soil triaxial test, the dynamic modulus of resilience test，analyse mechanism and process of subgrade structure strength decay, establish prediction model of subgrade strength decay, thus research results can provide accurate data for road design in strong evaporation area to reduce roadbed diseases affect and improve subgrade performance.