边坡剥落问题是黄土区公路边坡普遍发育的一种地质病害。边坡剥落降低了坡面的美观程度，不符合现代公路建设"安全、环保、舒适、和谐"的要求。研究黄土边坡剥落问题对于指导公路工程，确保公路稳定，降低养护成本，延长公路的使用年限将发挥重要作用。 本文的主要研究工作如下：（1）对黄延高速公路的剥落情况进行野外调查，总结其主要剥落类型及特点。（ 2）通过对洛川剥落区和三原未剥落区两种地区土样的物质组成、物理性质、抗剪和压缩特性进行对比性试验研究，总结出剥落边坡黄土性质的变化规律。（3）针对干湿循环作用对黄土的物理、力学性质以及宏细观结构的影响进行室内试验研究，通过试验分析黄土的质量损失、液塑限变化情况、剪切强度指标、压缩强度指标、 外在宏观结构及内在细观结构的变化，探求了不同干湿循环次数、不同含水率条件下黄土性质的变化规律以及干湿作用下黄土边坡剥落病害的形成机理。 本文从室内试验出发，展开剥落和不剥落区两种土样的对比试验和室内干湿循环试验，揭示了剥落边坡黄土的物理力学性质及干湿作用对剥落边坡的影响机理，无论在理论上还是在工程应用上，都具有重要的实际意义。

Slope spalling is a commonly developed geological hazard in highway slope loess region.It has reduced the aesthetic degree of slope surface, which doesn’t meet the requirement of"secure, environmental friendly, comfortable and harmonious" for modern highway. To study the spalling problem of loess slope will play an important role in instructing highway projects,ensuring road stability, reducing the ma intenance cost and extending it’s service life. The ma in endeavor and contributions of the dissertation are as follows:(1) Based on the field survey of spalling condition of Huangyan highway, summarize s the ma in types and characteristics of spalling.(2) Through comparative experiments on materia l component, physical appearance, shear and compression characteristics of the soil sample of two areas between spalling slope of luochuan loess and without peeling slope of sanyuan loess,summarizes the changes of loess properties of spalling slope .(3) A few lab tests are conducted to study the physica l, mecha nical properties , the macrostructure and meso-structure of loess that effected by wetting-drying circulation function, through the experimental analysis the change of quality loss, liquid limit and plastic limit, shear strength index, the compression strength index, external macrostructure and internal meso-structure, explore the law that the loess nature changes in different circulation number and different water conditions and the forming mecha nism of spalling diseases of loess slope under wetting-drying circulation function. Based on the laboratory tests ，the paper carries out research on contrast test for two kinds of loess samples in spalling and not spalling area and indoor dry-wet circulation experiment,reveal the physical, mechanical properties of loess on slope spalling and the dry-wet circulation effect on the forming mecha nism of slope spalling, both in theory and in engineering application, which have important practical significance.