Subway Investigation Parameters Analysis and Determination of Cretaceous Strata in Changchun District

Cretaceous conglomerate and mudstone universally exist in Changchun district,but conglomerate is difficult for sample drilling to do laboratory tests; mudstone is affected by many factors such as water stability,expansibility and slaking; many parameters,such as bearing capacity value,shear test parameter,permeability coefficient and coefficient of subgrade reaction,confirm mainly by empirical data evaluation method,There has a big difference on parameter rationality and accuracy.The article proposed bearing capacity values,shear strength,parameters,permeability and in-situ coefficient of subgrade reaction and so on by in-situ plate loading test,water immersion loading test and in-situ shear test on mudstone and conglomerate of cretaceous strata in Changchun district,,providing a geological reference for subway design and construction.