Investigation Of Damage Features And Study Failure Mechanism To Protection Engineering For Debris Flow In The Wenchuan Earthquake Region

On the basis of investgation and study of the debris flow protection engineeringsin Wenchuan earthquake region,collecting debris flow survey and design of basicdatas,etc,analysis of the typical debris flow for the develope characteristics and damagecharacteristic parameters of the outbreak in the Wenchuan earthquake zone after theearthquake.Based on investigations of debris flow protection engineerings damaged bythe debris flow, classifies and statistics of the damaged features; The failuremechanism of various types of protection, combined with a Numerical Simulation ofinversion analysis of the debris flow protection structure by the mechanism of ofmudslides stone impact and damage mechanisms, study feedback to the design.Depthstudy and analysis,and destruction mechanisms have a more profound understandingof the combination of numerical simulation reproduces the earthquake zone drainagecanal, Landslide Dam damaged by mudslides stone impact, and its stress, strain anddamage characteristics.The follows are mainly onclusions:(1)The mainly damagetypes ofdebris flowdrainage groove inWenchuanearthquake zoneare:Basis of Amoy eclipse–dumpingtype,Basis of Amoy eclipse–scattered(located) type,Stone impact-fragmentation type, Stone impact-collaps typeand Earth pressure-overturning (pushing)type;Drainage groove damagedcharacteristics statistics show that Basis Amoy eclipse-scattered (located) type ofdamage ratio is29%; Stone impact-collaps damage ratio is30%; Basis of Amoyeclipse-dumping of damage ratio is18%; stone impact–fragmentation type damage ofthe proportion engineering is12%; earth pressure–overturning(pushing) cover damageto the proportion is11%. The results show that the stone impact–collapstype and theBasis Amoy eclipse-scattered (located) type are the mainlydamagetypes;(2)The mainly damagetype of debris flowLandslide Damof Wenchuan earthquakezone are: Dam foundation the Amoy erosion–toppling type, Dam foundation theAmoy erosion-scattered type, Penetration–erosion type, Stone impact-fragmentationtype and Impact-outbursttype;Dam foundation the Amoy erosion-toppling theproportion of the damage to17%,dam foundation the Amoy erosion-scattered-damageratio of29%,penetration-the ratio of erosion damage to13%, stone impact-fragmentation damage to the proportion of15%, the impact-outburst of damage to theproportion of25%. The survey results show that the the Amoy Wenchuanearthquake-stricken area after the earthquake, debris flow Landslide Dam foundationerosion caused damage to the proportion of47%, including the dam foundationdumping and its foundation scattered type, is the main damage mode of the debris flowLandslide Dam;(3)The study results show that the basis of the drainage groove scouring erosion-toppling wrong(block)off the type of damage mechanism is the basis of channel and thedrainage groove by debris flow scoured drainageslot by the force changes, resulting inthe structure of the dumped or scattered destruction; stone impact-fragmentation typecollapsibility type, resulting in the structure of the surface crack or cracked due to theimpact of role of the debris flow stone, resulting in a large deformation, the formationof pitsdamaged by the impact of the stone; drainage groove earth pressure-pour (push)overlying the damage mechanism of loss caused by factors active earth pressure of thechannel on both sides of the slopes, damage to the structure of the damage mechanismis similar to the gravity retaining wallmechanism is due to earth pressure pushing theformation of the nappe destruction;(4)Drainage groove by the stone impact damage to the numerical simulationresults show that deformation of the structure of the surface by the impact isinstantaneous exposure to the size of the impact of law to the impact tangential impactforce, followed by Z-to the minimum; nodethe displacement is characterized by thedirect impact of the strong deformation zone than the average deformation zone;drainage groove for the damage process: the impact deformation-to destroy failuredeformation-bulk drop, the formation of pits;(5)The debris flow Landslide Dam damage mechanism is mainly the nature of thedebris flow and force structure decisions, the different damage patterns and damagemechanisms. debris flow dam foundation scouring erosion-toppling scattered damagemechanism of the channel and dam foundation scoured by debris flows, the dam of force change, resulting in the structure of the dumping or scattered destruction;penetration-erosion damage is due to high head dam upstream to the formation of theconcentrated seepage caused by the penetration of deformation, resulting in seepagechannels expanding, carrying away a large number of particulate matter, resulting in thedam foundation formation overhead phenomenon, which reduce the bearing capacity ofthe overhead structure, resulting in dam foundation destruction; stone impact-fragmentation type is due to the role of the impact of the debris flow stone surface crackor fragmentation of the dam structure, resulting in large deformation, the formation ofpits, etc., damaged by the impact of the stone; impact-outburst Landslide Dam losscaused by the main factors for the debris flow flow viscosity, velocity, impact, which istypical of mechanical damage mechanisms;(6)Landslide Dam stone impact of the numerical simulation results show that thestone impact dam, the moment of the kinetic energy on impact deformation energy,internal energy, and the remaining kinetic energy; dam for the positive impact ofcontact with the size of the impactfor the law to impact the Y direction followed, and Zto the minimum; dam of the elastic and plastic deformation characteristics indicate thatthe deformation of the dam by the impact at the moment of impact, thepost-deformation stabilized; dam by the impact the evolution ofthe process: the impactdeformation deformation-to destroy failure-falling blocks, the formation of pits.