A constitutive model is proposed for describing the main behaviors of sandy soil under cyclic loading, and the laboratory tests of soil mechanics under different confining pressure and various stress paths have been performed for determining the material constants.

Based on the analysis of the measured results,the basic methods of supervisory measurements on tunnel construction under the complex conditions that surrounding rocks are mainly sandy clay are introduced;and the basic deformation regularity of similar tunnel and ground are also summarized.

For improving roadbed filling by adding quicklime to silty sand, the authors obtain some experimental data about improved soil.

With engineering practice,the article analyzes reasons of ground settlement when shield driving is conducted through sandy silt stratum; and it also sums up the secured measures.

An introduction is given to the comprehensive construction technology for the tunnel with sandy silt and complicated surrounding environment, including waterproof technology, settlement prevention, and old tree protection.

Based on a large amount of field and laboratory tests the standard and methods for the liquefaction evaluation of sandy silt in the old course of Suzhou River are presented.