Through analyzing causes of three kinds of quality accidents in construction of drill-grouting pile, which including short pile、broken pile and necking pile, and summarizes relative treatment, the result indicates which can meet demand of design and application.

In the process of optimal design of foundation reinforcement for the typical project,by means of finite element analytical method,systematic calculation and analysis have been conducted aiming at raft foundation and foundations reinforced by short pile,long pile,and long-short composite pile respectively.

It will reduce the construction cost and take less time to finish the project and use short piles and set supporting courses at shallower positions than usual according to the field condition.

New design ideas for piles are put forward,which may serve as a reference for similar engineering design.

Research purposes:Through doing overall researches,it is proposed to adopt flat-slab beamless pile structure for low embankment of soft weak subgrade,which can be suitable for ballast and ballsatless tracks and control the structure s settlement with easy construction and low construction cost.

Local scour around cylinder under wave action;

The interaction between internal waves and a horizontal cylinder is studied by using a laboratory experiment,the focus being the dependence of the factors of the internal waves on the resistance of the horizontal cylinder induced by the internal wave.

In recent years, the studies on internal waves generated by the moving bodies and drag increment caused by the stratification, and of forces and loading of cylinders exerted by the internal waves are paid considerable attention by physical, engineering and military oceanographer.