The Engineering Character Of Improved Soil And The Experence Of The Construction Of Qin-Shen Quick-Speed Railway

It is very important for railway subgrade whether the engineering character of the filling is good or not. In order to ensure the quality of filling and the construction stability of the high - speed railway subgrade. " prescription of design of line ,bridge, tunnel and station of high -speed railway " regulated that the filling used in the bottom of high-speed railway subgrade must be the type of A ,B or improved soil. But according to the survey result of filling characteristic of the area that Jing-Hu high-speed railway is going to pass through , the eligible filling is very poor .It will be very expensive if the all filling that used in subgrade construction transported form other region.The characteristic and distributing of filling along Jing-Hu high-speed railway are introduced. The sort and stabilized of subgrade filling all over the word are discussed .On the base of analyses of developed and present for improved soil ,the theory and character of each improved soil are studied form physics and chemistry. The indoors tests of compaction , liquid and plastic limit ,strength ,permeability and compres-sion are done ,including cement-improved-soil ,lime-improved-soil ,lime-fly ash -improved soil. The correctness and rationality of mixing proportion is proved according to the site of Qin-Shen quick-speed railway .And the construction technics of each improved soil are summarized.