Study On Compaction Quality Control Technology And Settlement Mechanism Of Backfill With Stagger Slag

Because of the particularity of the position,the back of the platform is easy to produce a large settlement,so the quality of the backfill is higher.High slag strength,strong anti-erosion ability and small settlement deformation,it is used as a good selection of backfill.However,at present,there is a lack of material selection standard for backpacking of slag backpacking,and there is a lack of related research on the quality control technology and settlement law of backpacking of slag backpacking.Therefore,based on the Ji-wei Expressway slag back-off project,this paper conducted a large number of experimental studies on the physical and mechanical properties of slag back-off,vibration compaction characteristics of slag back-off,compaction quality of slag back-off and settlement deformation law through theoretical analysis,laboratory test of slag back-off,field compaction quality test of slag back-off and settlement monitoring and other methods.The main research results are as follows:(1)Taking the dry density as the measurement standard,the geometric similarity method was determined as the treatment method of excess particle size.Based on this method,the best stone content and its gradation type are obtained after the compaction test.By adjusting the compaction times of each layer,the power function relationship between the total compaction times and dry density was established,and the best compaction work was obtained.(2)The indoor test of vibratory compaction on the surface of slagging material was carried out by using the self-made large vibratory compaction square cylinder.With the vibratory dry density as the judging index,the optimal stone content of slagging material was verified,and the optimal compaction mode,vibration frequency and vibration time were determined.Based on the changes of horizontal and vertical vibration acceleration,four stages of vibration compaction,including initial vibration compaction,particle adjustment,vibration compaction supplement and vibration stability,are given.(3)Through the field compaction quality test of the back of the slag station,the conversion relationship between the static and static bending values was obtained,the relationship between the rolling pass number and the rolling settlement difference was obtained,the relationship between the rolling settlement difference and the Evd value was established,and the method of quickly evaluating the compaction quality of the back of the slag station based on the Evd value was proposed.Based on the research results in Chapter 2～4,the vibration acceleration of the light wheel of the roller is proposed as another new control index,and a set of quality control technology for back compaction of slag table is formed,which is composed of material selection index control,construction process control and real-time compaction quality detection control.(4)The real-time monitoring results show that when the slag material is broken down,it is a kind of backfilling with good performance.The settlementdeformation of the slag back is spatiotemporal.From the perspective of time,the change of the settlementof the slag back can be divided into three stages: rapid occurrence,slow accumulation and convergence stability,and the cumulative settlementgradually increases and tends to converge.From the perspective of space,in the same monitoring period,the accumulated compression of the same cross section on the back of the slag table decreases from the middle to both sides,showing a "V" shaped change.