面波法识别青藏高原冻土地基高含冰量冻土空间分布和力学特性研究OA

As the Qinghai-Tibet Plateau continues to warm and humidify,the uneven degradation of perma-frost increasingly threatens transportation infrastructure.Rapid assessment of permafrost distribution and me-chanical properties is therefore essential for engineering construction and maintenance.This study,focusing on the permafrost foundations of the Xiangride-Huashixia section of the De-Ma Expressway,introduces a geo-physical exploration approach based on the transient Rayleigh surface wave method to efficiently determine the upper boundary and spatial distribution of permafrost.By inverting surface wave data,a three-dimensional dis-tribution model of ice-rich soil layers is established.The inversion results are validated through borehole sam-pling and laboratory tests,which clarifies the relationship between surface wave velocity and soil physical-mechanical properties.The key findings are as follows:the surface wave method demonstrates high accuracy in permafrost surveys,effectively identifying both high-ice-content permafrost and thaw zones in-duced by roadbed service;surface wave velocity responds synchronously to variations in ground ice content with depth,with frozen-state velocities being 0.3-0.5 times higher than thawed-state values;combined with laboratory testing,a predictive model of shear strength for permafrost with varying ice contents is developed based on surface wave velocity,enabling strength estimation of permafrost foundations;and due to the heat ab-sorption of existing pavements,high-ice-content permafrost beneath the roadbed exhibits a pronounced gradi-ent reduction.Overall,the results confirm that the transient Rayleigh surface wave method is an economical and reliable tool for permafrost investigations,offering new technical insights for assessing permafrost distribu-tion and foundation conditions in cold-region road engineering.