The Research Of Maoxian Kudiguazi Landslide’s Formation Mechanism And Seismic Effect

Maoxian Kudiguazi landslide is located in the Maoxian Longmen tectonic beltand the Minshan block the effects of high intensity area, the terrain is deeply incisedvalley, rock is bedding and perpendicular to the slope of the two sets of joints cuttingmore into the broken block of strong weathered phyllite. Field investigation foundthat the river blocking phenomenon, and geological phenomena of earthquake leftslope, mainly for sand liquefaction, parallel to the sliding direction, vertical cracks thewrong Kan, filling wedge, Banpo lake sediment, bitter melon seeds, judge landslide isan old landslide. Based on the field investigation, combined with laboratory datacollection, numerical simulation methods, the engineering geological conditions ofthe landslide area, accumulation, partitioning, deformation features of the research,analysis of its special geological phenomenon and the deformation and failuremechanism, through the numerical simulation of the failure process is the original,and the occurrence of large deformation of the various parts of the slope dynamicresponse to earthquake loading conditions, we get the following conclusions:(1) according to the process and the slope into the source region of the landslideformation, accumulation (I) and (II) the accumulation area, and according to thesedimentary characteristics and the characteristics of deformation and damageaccumulation can be divided into colluvial accumulation zone (II1), lake sedimentcovered area (II2) and continuous deformation failure zone (II3).(2) special geological phenomenon on residual landslide, including parallel tothe sliding direction signs, sand liquefaction crack front slope on the upright wrongKan, landslide and central filling wedge, the upper part of the landslide in landslidehalfway up the mountain of Lake sediments. Landslide is difficult to explain thisphenomenon normal gravity, the special phenomenon of earthquake landslide legacy.(3) regional uplift and cutting Valley resulting in high steep slope rock valleyformation, this occurs in the process of unloading, cracks, the earthquake in theearthquake on the slope surface tensile stress, crack under the action of the vibration of the upper slope deformation fragmentation and began, front lock fixed section inshock tensile stress and the upper slope gravity pressure is cut, bitter melon istriggered landslides landslide, high speed, large landslide an instant influx byBlackwater river opposite mountain barrier deposition in the Blackwater River, riverblocking the formation of the lake, lake sediment deposition in the lake, once again bythe earthquake effects, liquefaction phenomenon occurred in the lake sediments,(4)through the UDEC software to simulate the process of landslide, landslidedeformation analysis of dynamic response of before:(a) from the slope front shear opening upwards, amplification effect ofacceleration, velocity and displacement monitoring points have different degree.(b) front was "locked", the displacement and velocity of the smallest.(c) slope at each monitoring point acceleration, velocity and displacement, peakhorizontal direction are larger, more obvious shear wave function.(d) displacement of the slope body is far greater than the displacementmonitoring points lower monitoring points, that is from the upper slope deformationand failure, but because the front shear displacement near the exit of small changes, sothe first appears in the upper slope landslide arch "capacity expansion" phenomenon.(e) the slope deformation and destruction from the upper part of the beginningin order to exclude the formation mechanism of landslide sliding tension, is strongevidence of the formation mechanism of Landslide Motion tension.To sum up, Maoxian bitter melon seeds landslide deformation mechanism: uppervibration tension, front lock fixed section shearingâ†'landslide initiation.