Study On Selection Methods Of Highway Loess Slope Parameters Of Shanxi Province

Through participating in the project of Shanxi Communications Department "Study on slope stability and engineering measures in loess areas of highway", investigating the road of the loess areas of Shanxi, sampling for laboratory tests to obtain the loess physical and mechanical properties indicators which were combined with the information in Shanxi loess areas of Highway Engineering Geology Division; drawing the various lines of a typical slope profile, summing up the four types combination strata. Finally, on the basis of the analyzing strength parameters, district results and the slope failure mode, the author proposed a principle and method of selection strength parameters of loess slope stability analysis, provided theoretical basis for loess slope stability analysis and protection design in Shanxi Highway, achieved the results as following:According to climate differences of the loess areas, geographic differences in geomorphology, geological features of loess, a variety of physical and mechanical property index, the paper took a study on engineering geological zoning for the loess areas of Shanxi highway, the Shanxi Province was divided into three major areas, eleven sub-district and loess slope distribution of the concentration of loess hilly and gully region (I) physical and mechanical parameters, statistics and obtained the summary of the regional loess physical and mechanical indicators, provided the basic data for Shanxi Loess highway slope construction.Detailed investigation on the loess slope of the Shanxi Province had built roads, according to the terrain conditions, the causes of age of the loess, loess stratigraphic architecture, Shanxi Road loess slope shall be designated into four categories, respectively as loess (Q3) single form (Ⅰ), new and old loess (Q3+Q2), the combination of (Ⅱ), the old loess (Q2), a single form (Ⅲ), loess and bedrock (Q2-3+T1(or P)) combination form (Ⅳ), and field investigation to analyze the failure modes of the different combinations of loess slope, in the form of a bad slope of slope failure and slope, pursuant to the Loess Hilly Region (Ⅰ) within the highway loess slope failure mode. According to this article in loess slope design, you should first consider the highway engineering geological zoning, combined with a different failure mode, In addition to considering the slope stability, the situation of slope failure must also considered.On the basic of investigating the relationship of the peak intensity,"Starting Strength"(plastic water content corresponding to the intensity) and residual strength, the paper took engineering practice as an example, selected slopes in a combination of forms in different partitions on different strata, using the peak intensity,"start strength" and residual strength to affect stability and slope of the stress distribution analysis and showed that:in different engineering geological zoning, different strata of the combination of slope, slope type, stability evaluation results by the different intensity parameters are value of the degree of influence is very obvious, and slope failure modes may be also different, which means that the actual road slope stability evaluation must consider a reasonable choice to the peak intensity,"start strength" and residual strength.Finally, considering engineering geological zoning and slope failure modes of the Shanxi loess highway, the anthor proposed the selection principles and methods of the loess slope stability analysis of Shanxi loess hilly road strength parameters:in Shanxi loess hilly area engineering geological zoning region of I, the road through this region, where the Ministryern—Ⅰ b:the slope design strength parameters recommend the residual strength; northern—Ⅰ a:slope breaking is mainly to slope failure, the main priority should be given to the peak intensity of the slope design; Southern——I c:during slope designing preferr the "Starting Strength".