Research Of Key Technology In The Backwall Subgrade Which By Pumping Filling Self Compact Mud-fluid Into Backwall's Large-size-rockfill

Problems about vehicle dumping at bridgehead is is one of the most common diseases and hidden dangers in highway construction,when the vehicle is traveling to the bridge,In order to avoid the phenomenon of jumping,it often need to take braking deceleration,the speed of the vehicle is greatly reduced,the problem affect the traffic capacity of the road,seriously damaged the economic and social benefits of highway construction.In this paper,according to the theory of rigid and flexible transition,based on the technology of non compacted backfill,rockfill and self compacting rock fill concrete,puting forward a new technology of back filling,which is research on pumping filling self compact mud-fluid into backwall ' s large-size-rockfill.The technology on the back filling backwall subgrade using waste mud of bored pile foundation or pond dredging construction,add a certain amount of curing agent to waste mud as filler,large size stone from roadbed pile as rockfill.By pumping filling self compact mud-fluid into backwall's large-size-rockfill,became a roadbed of large size particle and solidified mud mortar.In this paper,the preliminary experiment and basic theory of this technology are studied.The main research contents and achievements include the following aspects:(1)Based on the investigation of the surface characteristics of super large diameter filler,the accumulation of large diameter stone was studied.And according to the characteristics of the pore structure formed by the aggregate accumulation of the large diameter rock mass,the paper puts forward the method of two grades of gradation to form the skeleton structure of the large particle size;(2)The mud mortar curing agent filling were studied,discussed the mechanism of mud solidification,And the orthogonal test method was used to design the mix proportion of mud curing agent.On the basis of mix proportion design,the effects of different dosages of curing agent on the expansion and compressive strength of slurry flow were studied,At the same time,the durability of the mortar was studied by the freeze-thaw cycle test;(3)By studing the working performance of consolidated mud mortar pouringlarge size rockfill,and the the formation of large grain size Rockfill curing cement mortar foundation were using simple theoretical analysied.On this basis,according to the similar literature and experimental data,using the ANSYS finite element software,the numerical simulation of the subgrade settlement of the abutment is carried out.The simulation results show that this method can greatly reduce the settlement difference between bridge abutment and abutment,probably decreases about 5 cm,the slow transition of abutment,abutment and subgrade settlement is realized;(4)On the basis of theoretical research,the construction technology is discussed briefly.