Zheng Yingren

Development and application of numerical limit analysis for geotechnical materials

Solid material develops from elastic to plastic then to failure after undertaking some load,which means that yield is different from failure.The system of yield criteria for geomaterial is discussed and two definitions which are point failure and surface failure in stress field are put forward.And the criteria of surface whole failure is defined through traditional limit analysis method.Simultaneously,the deficiencies for traditional limit analysis and numerical analysis are pointed out by reviewing and analyzing the solution characteristics of traditional limit analysis method.Based on the combination of these two methods,a newly developed numerical limit analysis method is built,which has enlarged the application rage of limit analysis.The significances and features of traditional limit analysis method and numerical limit method are studied,as well as the reliabilities.The advantages and disadvantages of numerical limit analysis are listed;and the wide applicability of numerical limit analysis in the slope(landslide) engineering,foundation engineering and tunnel engineering is illustrated.

Notice of Retraction Reinforcement mechanism of the deep buried piles by series model tests

To be examined the reinforcement mechanism of deeply buried piles, series of large scaled model test has been carried out. Several testing tools including rigid load cells, the earth pressure cells are employed to measure the pressure received by deep buried piles and the slope thrust of the slope on piles top. On the basis of the variation process of measured data, the time and the location of slide surface in the slope is determined, and the maximal anti-sliding force upward to the piles top could be gained. Then the failure form process is analyzed as the anti-sliding length of the piles changed. The relationship between the sliding force received by the piles and that supplied by the slope on piles top is analyzed to supply scientific demonstration for the design method of slope reinforced by the deeply buried piles.