Zhashui To Xiaohe Highway Soft Rock Embankment Settlement Analysis And Post-construction Settlement Prediction

When it comes to the construction of freeway in mountain areas, due to environmental constraints, the source of soil embankment filling is a major problem, and tunnel spoil or discard slope cutting is usually used as embankment filling in engineering practice. But at the moment, there isn't a sufficient study about disquisition of rock-fill embankment, and none standard can be relied in this aspect in China. Zhashui to Xiaohe Freeway lies in the Qinling Mountains, which use metamorphic soft rock as embankment filling. But the freeway has strict requirement on settlement of road surface, and metamorphic soft rock has an adverse engineering property about water softening; in order to guarantee construction quality, the research of metamorphic soft rock embankment settlement needs to be developed.This Paper base opinion on lots of reference materials analyzes and summarizes the concept of soft rock in subgrade engineering. Based on mineral composition analysis, naming test and uniaxial compressive strength test before and after soaking, the natures of the soft rock of the original metamorphic soft rock are studied. Using maximum dry density test and large-scale compression test to investigate engineering properties of this kind of rock before and after soaking. On these bases, conduct the large-scale indoor soaking metamorphic soft rock embankment deformation test for the first time, which make up the defect that the previous test size is too small to bring. At the same time, the uneven settlement control standard of metamorphic soft rock:embankment and theory to settlement calculation are studied. Combined with the field measured post-construction settlement data, post-construction settlement prediction methods are studied, several conclusions are listed as follows:1)This Paper puts forward the the uneven settlement control standard of metamorphic soft rock embankment is 3.5 cm;2)Two Parameters Ma, Mb to describe the differences between embankment settlement before and after soaking are proposed.3)The correction factor Ms of layer-wise summation method is presented. 4) In the four curve fitting prediction methods, hyperbola method is more suitable to predict this kind of metamorphic soft rock embankment.5)The feasibility of embankment with this kind metamorphic soft of rock is verified.