干湿循环作用下红粘土力学性能衰减规律研究

With the national policy tilted to the west, the infrastructure constructions such as expressway networks and railway networks in Guizhou province are growing vigorously. Because of the special engineering properties of red clay, the mechanical properties of red clay becomes vestigial gradually during wetting- drying cycles and repeated traffic load.The long-term strength and stability of red clay subgrade declines so that it causes a variety of diseases, specially the subgrade surface cracking seriously because of water losses. Focusing on the red clay subgrade diseases, aiming to a gap of red clay study, through the field investigation, theoretical analysis, laboratory and field tests,the project researches the following contents for the red clay as a subgrade filling used the Guizhou highways during wetting-drying cycles:(1)the parallel experimentation of mechanical property under the condition of general temperture and drying;(2)the strength declining law;(3)the dynamic characteristics;(4)the expansion-contraction deformation property.The road performance of red clay during wetting- drying cycles and repeated traffic load are made known. The result has high academic value in the optimization of the evaluation systems of the road performance for red clay. The result also provide scientific basis for designs and constructions for the later red road construction.In the meanwhile the result has great economic and social benefits in prolonging the highway service life and reducing the maintenance costs.

随着国家政策向西部地区倾斜，贵州高速公路网、铁路网等基础设施建设如火如荼。由于红粘土特殊的工程性质，在干湿循环作用和反复的交通荷载作用下红粘土力学特性退化，红粘土路基长期强度和稳定性下降，使得路基产生多种病害，特别是路基表面失水收缩开裂严重。课题针对红粘土路基病害的现象，就目前红粘土研究中的盲点，以贵州公路建设中遇见的红粘土为研究对象，通过现场调研、理论分析、室内外试验，研究红粘土在室温下和烘干状态下干湿循环作用红粘土力学特性的对比规律、干湿循环作用下强度衰减规律、动力特性衰减规律和胀缩变形特性的衰减规律，揭示红粘土在干湿循环和反复交通荷载条件下的路用性能。研究成果对红粘土路用性能评价体系的完善具有重要的学术价值，为今后红粘土地区公路建设提供一定的设计施工依据，对延长公路使用寿命、减少养护管理费用，具有重大的经济效益和社会效益。

随着国家政策向西部地区倾斜，贵州高速公路网、铁路网等基础设施建设如火如荼。由于红粘土特殊的工程性质，在干湿循环作用下红粘土力学特性退化，红粘土路基长期强度和稳定性下降，使得路基产生多种病害，特别是路基表面失水收缩开裂严重。课题针对红粘土路基病害的现象，就目前红粘土研究中的盲点，以贵州公路建设中遇见的红粘土为研究对象，通过现场调研、理论分析、室内外试验，研究红粘土在室温下和烘干状态下干湿循环作用红粘土力学特性的对比规律、干湿循环作用下强度衰减规律、动力特性衰减规律和胀缩变形特性的衰减规律。得到了室温下和烘干状态下干湿循环作用红粘土强度与变形特性的对比规律、强度指标的衰减规律、胀缩变形的规律以及裂缝的演化规律，提出了干湿循环下红粘土动本构方程，揭示了红粘土在干湿循环条件下力学性能。研究成果对红粘土路用性能评价体系的完善具有重要的学术价值，为今后红粘土地区公路建设提供更加完善的科学依据，对延长公路使用寿命、减少养护管理费用，具有重大的经济效益和社会效益。