Time effect of wet drilling pile is investigated through the static load experiment on pile No. 22 of Guanhe Bridge. Post-grouting under pile tip is adopted in the project. To study the bearing performance of the pile...Time effect of wet drilling pile is investigated through the static load experiment on pile No. 22 of Guanhe Bridge. Post-grouting under pile tip is adopted in the project. To study the bearing performance of the pile, the self-balanced method is used and two load cells are assembled in the pile body. The experiments are carried out before and after post-grouting. The upper part of the pile is not influenced by post-grouting under the pile tip. Experimental results of the upper part of the pile show that the bearing capacity and the rigidity of wet drilling pile increase with time passing on. Analysis results show the time effect of wet drilling pile is influenced by many factors, such as alteration of stress field around pile, characteristics of soil around pile, variety of mud cake, and property of residue under pile tip.展开更多
As a good method to solve the problem of high methane on the workface and inthe goaf,drawing coal strata methane through a surface borehole is used.However,theexcavation affected the overlying rock strata greatly.When...As a good method to solve the problem of high methane on the workface and inthe goaf,drawing coal strata methane through a surface borehole is used.However,theexcavation affected the overlying rock strata greatly.When the excavation face passedthrough the surface borehole position,the surface borehole fractures fast.This problemwas seriously related to the unformed squeeze effect.Therefore,a squeezing deformationfracture model based on the rock strata squeezing effect was set up.At the same time,a3DEC simulation model is presented to confirm the theory.The result shows that the modelis reliable and has a good engineering application value.展开更多
文摘Time effect of wet drilling pile is investigated through the static load experiment on pile No. 22 of Guanhe Bridge. Post-grouting under pile tip is adopted in the project. To study the bearing performance of the pile, the self-balanced method is used and two load cells are assembled in the pile body. The experiments are carried out before and after post-grouting. The upper part of the pile is not influenced by post-grouting under the pile tip. Experimental results of the upper part of the pile show that the bearing capacity and the rigidity of wet drilling pile increase with time passing on. Analysis results show the time effect of wet drilling pile is influenced by many factors, such as alteration of stress field around pile, characteristics of soil around pile, variety of mud cake, and property of residue under pile tip.
基金Supported by the National Great Research Foundation of China(973)(2005CB221504)the National Natural Science Foundation of China(50534080)the National Key Technology R&D Program(2006BAK03B03)
文摘As a good method to solve the problem of high methane on the workface and inthe goaf,drawing coal strata methane through a surface borehole is used.However,theexcavation affected the overlying rock strata greatly.When the excavation face passedthrough the surface borehole position,the surface borehole fractures fast.This problemwas seriously related to the unformed squeeze effect.Therefore,a squeezing deformationfracture model based on the rock strata squeezing effect was set up.At the same time,a3DEC simulation model is presented to confirm the theory.The result shows that the modelis reliable and has a good engineering application value.
