Rapid Repair Technology For Buried Highway By Giant Debris Flow

Debris flow is one of the main road diseases in western China,its hazards includeattacking and burying the highway subgrades,pavements,bridges and protectivestructures,the occurrence frequency of these two disasters is 6∶4. In the pastdecade,there are more than 50 bridges,culverts were buried by debris flow and thengradually destroyed , However,so far the buried-damage mechanism of debris flow onthe highway building structure is not clear,domestic and foreign experts andscholars'studies on the mechanical mechanism of debris flow deposit are verylimited.Therefore,according to this situation ,the project conducted a systematicstudy,the main conclusions and innovations are as follows:1.Constructed the test model of debris flow,then carryed out the buried-bridgemodel test of Tianshan debris flow .Through the model test,verified the presence ofconsolidation force during the process of debris flow deposition.2.According to the two-phase flow theory of debris flow deposit ,analysed theconsolidation mechanical mechanism of highway debris flow deposit. On the basis ofTerzaghi one-dimensional consolidation theory, established the consolidation formula,which described the change process of excess pore water pressure,consolidationdegree,settlement and compression with theconsolidation time and deposit size, and then verified the correctness and feasibility ofthe formula by the indoor consolidation test. Therefore, used these results and combinedwith the field survey data, could develop a proper program for emergency mitigation ofhighway debris flow buried disaster more quickly and accurately .3.On the basis of indoor micro-compression test,established the mathematicalrelationship expression between the bearing capacity and solid phase ratio/water contentof debris flow deposit,simplified the field measuring process of bearing capacity ondebris flow deposit foundation. 4.According to the variation between rheological consolidaiton and bearingcapacity of viscous debris flow deposit,established the highway traffic fast recoverycomplete technologies of debris flow buried sections,such as the emergency trafficload-bearing umbrella,war pontoon, then built the detailed construction methods anddesign procedures,the highway traffic recovery time would become to 3~5 days afterpopularization and application,which reduced more than 3 times than the currentrequired recovery time.5.Used the Tianshan K631 debris flow buried highway disaster as the controlobject,then designed and calculated the emergency bearing umbrella technology, theresult had proved that this technology could be well applied to the engineeringpractice.Besides, used the finite element software ADINA to simulate the debris flowdeposit-combat raediness pontoon coulped structure in three dimensions, then reflectedthe stress deformation process of combat readiness pontoon in the debris flow buriedsection, and obtained the result in accordance with the actual situation. Moreimportantly, it revealed qualitatively the details of debris flow deposit-combat raedinesspontoon action in the numerical simulation.