| In the process of such a rapid urban development, the problem of Xi’an city’s traffic jam has been increasingly prominent. Presented with the problem, whist seeking an effective way to facilitate regional economic and social development of surrounding areas, Xi’an city government will carry out the constructions of intercity rail system during the 12thfive-year plan, including lines of Xi’an-Xianyang international airport and Xi’an-Yangliang District,which would greatly close Xi’an city and its international airport, surrounding areas.The project of line Xi’an-Xianyang international airport has been in its preliminary stage of surveying rock soil mass which is to cover geomorphic units of the loess district on the Weibei mesa(the edge of the loess plateau) and river valley of Weihe River(riverbed and terrace).。Apart from indoor soil tests with samples from site drilling, series of in-situ testing technologies had been introduced to classify the stratigraphic profile and obtain more accurate and reliable parameters of rock soil mass under the condition that there are many underground stations and structures built along the project. To name just a few, static cone penetration tests,dilatometer tests and special test methods like lateral loading tests.Based on this background, the paper provides evidences for engineering design and construction with a combination of geotechnical survey in the project of intercity railway construction from Xi’an north station to airport. Aiming at the coverage of the loess district on the Weibei mesa, the paper is on the basis of drilling sampling, indoor soil tests, and in-situ tests in site with typical drill of ZK1-ZK4, thus to get accurate geotechnical parameters of rock soil mass.Work done in this thesis and its main researches are summarized as followings:1.Having drilled in the tested areas, strata structure of the site was correctly interpreted,and to acquire related physical indices of local soil, indoor soil tests done with samples like direct shear experiments and compression testing had been carried out.2.In-situ tests were conducted in the original drill site, mainly including static cone penetration tests, lateral loading tests and dilatometer tests.Cu:41、42、43、41、42、44、43k Pa.Then the deformation and strength parameters of the site’s soil were worked out aftercollecting and analyzing the data from in-situ tests.3.It was found that soil horizon classification according to the analysis of data from static cone penetration K0:0.38、0.40、0.41、0.39、0.39、0.41、0.38,and dilatometer tests was basically Kh:71、90、95、88、86、91、80k N/m3,the same as that on the basis of stratigraphic profile from drilling7.4% after compared the two classification results14.6%.4.Having compared and analyzed the deformation and strength parameters obtained from in-situ tests with those from soil tests K0:0.38、0.39、0.41、0.39、0.39, it was found that the results Kh:74、96、98、85、89 k N/m3,from two types of tests were very different, while those of the 3 in-situ tests didn’t appear to be much different and even could be authenticated mutually. 7.7%The comparison told the higher accuracy of in-situ tests than soil tests8.9%.5. Having drilled in the tested areas, strata structure of the site was correctly interpreted,and to acquire related09.04.39Du=KC and305.0036.0D=KK 。The above results of the study, not only ensure the project to be implemented safely, but also offer reference and suggestion for the forthcoming intercity railway system construction of Xi’an-Yanliang District and other projects covering the loess district on the Weibei mesa(the edge of the loess plateau) to choose proper strength and deformation of loess as the foundation and environment of the project. |
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