The objective of this work is to compare the responses of geosynthetically-reinforced embankment and unreinforced embankment due to road widening by using the centrifuge model tests and a two-dimensional(2D) finite el...The objective of this work is to compare the responses of geosynthetically-reinforced embankment and unreinforced embankment due to road widening by using the centrifuge model tests and a two-dimensional(2D) finite element(FE) model. The measured and calculated responses of the embankment and foundation exposed to road widening include the settlement,horizontal displacement,pore water pressure,and shear stresses. It is found that the road widening changed the transverse slope of the original pavement surface resulting from the nonuniform settlements. The maximum horizontal movement is found to be located at the shoulder of the original embankment. Although the difference is small,it is clearly seen that the geosynthetic reinforcement reduces the nonuniform settlements and horizontal movements due to road widening. Thus the reinforcement reduces the potential of pavement cracking and increases the stability of the embankment on soft ground in road widening.展开更多
Breaching of embankments has recently drawn more and more attention due to its importance in the development of early warning systems for embankment failures,in the evacuation plans of people at risk,in the design met...Breaching of embankments has recently drawn more and more attention due to its importance in the development of early warning systems for embankment failures,in the evacuation plans of people at risk,in the design method of embankments based on a risk-approach,etc. The erosion process observed during embankment breaching tests in the laboratory and the analysis of the results are described in this paper. Five embankments,one constructed with pure sand,four with different sand-silt-clay mixtures were tested. The height of the embankments was 75 cm and the width at the crest was 60 cm. Examination of the data from these tests indicated that headcut erosion played an important role in the process of breach growth in the embankments made of cohesive soil mixtures. Flow shear erosion,fluidization of the headcut slope surface,undermining of the headcut due to impinging jet scour and discrete soil mechanical slope mass failure from the headcut were all observed during these tests. For the embankment constructed with pure sand,the breach erosion process was dominated by shear erosion,which led to a gradual and relatively uniform retreat of the downstream slope. The cohesive proportion in the sand-silt-clay mixtures strongly slowed down the erosion process.展开更多
基金Project(200231800032) supported by Research on Transportation Construction in Western, China
文摘The objective of this work is to compare the responses of geosynthetically-reinforced embankment and unreinforced embankment due to road widening by using the centrifuge model tests and a two-dimensional(2D) finite element(FE) model. The measured and calculated responses of the embankment and foundation exposed to road widening include the settlement,horizontal displacement,pore water pressure,and shear stresses. It is found that the road widening changed the transverse slope of the original pavement surface resulting from the nonuniform settlements. The maximum horizontal movement is found to be located at the shoulder of the original embankment. Although the difference is small,it is clearly seen that the geosynthetic reinforcement reduces the nonuniform settlements and horizontal movements due to road widening. Thus the reinforcement reduces the potential of pavement cracking and increases the stability of the embankment on soft ground in road widening.
基金supported by the National Basic Research Program ("973" Program) of China (Grant No.2007CB714106)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Hu-man Resources and Social Security of China+1 种基金the National Natural Science Foundation of China (Grant No.51009012)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry
文摘Breaching of embankments has recently drawn more and more attention due to its importance in the development of early warning systems for embankment failures,in the evacuation plans of people at risk,in the design method of embankments based on a risk-approach,etc. The erosion process observed during embankment breaching tests in the laboratory and the analysis of the results are described in this paper. Five embankments,one constructed with pure sand,four with different sand-silt-clay mixtures were tested. The height of the embankments was 75 cm and the width at the crest was 60 cm. Examination of the data from these tests indicated that headcut erosion played an important role in the process of breach growth in the embankments made of cohesive soil mixtures. Flow shear erosion,fluidization of the headcut slope surface,undermining of the headcut due to impinging jet scour and discrete soil mechanical slope mass failure from the headcut were all observed during these tests. For the embankment constructed with pure sand,the breach erosion process was dominated by shear erosion,which led to a gradual and relatively uniform retreat of the downstream slope. The cohesive proportion in the sand-silt-clay mixtures strongly slowed down the erosion process.
