Study On Energy Coupling Between Internal Dynamic Effect And Surface Catastrophic Effect In Longmenshan Fault Zone

The coupling effect between the crust dynamics and the superficial catastrophic process is a basic and frontier scientific problem.In particular,in the Longmenshan fault zone,the dynamic environment of the crustal structure is extremely complex and the superficial geology plays a very strong role,which seriously restricts the construction of towns in the mountainous areas and the promotion and development of the national economy.This paper focuses on the energy coupling of the internal dynamics and surface catastrophic effects of the Longmenshan fault zone,and conducts field surveys of the geological sections and rock structure characteristics of the Wenchuan Earthquake in the core area(Qingping-Hanwang Mianyuan River Basin).Using the statistics of joint fractures of 0.3 m × 0.3 m rock mass in the 2.0 × 2.0m precision survey control network and joint rock mass density calculation methods,the sequence characteristics of the fractured structural system of the crust rock mass in the fault zone were ascertained,and the Longmen Mountain was accurately determined accordingly.The fractured tectonic fracture zone affects the zone.Based on this,through the systematic analysis of the zoning characteristics of the fracture zone of the fault zone,the fractal geometry features(including the fractal features of the rock structure and the fractal characteristics of the rock mass)and the fracture of the rock mass are mainly studied and discussed.The correlation with the fractal degree fractality.And then use the fractal characteristics to study the energy distribution characteristics from rock mechanics experiments(impact,triaxial compression)theory,and establish a more accurate geological-rock mass-energy model.Finally,this energy model is combined with the features of Wenchuan earthquake-induced geological disasters,and discussed in detail from the aspects of the energy characteristics of rock masses and the regional statistical laws of Wenchuan earthquake geological disasters and the coupling calculations of typical monolithic earthquake landslide energy and regional rock mass energy characteristics.The correlation between geological disasters and research results has made progress in the coupling of dynamic and surface catastrophic effects within the Longmenshan fault zone,the internal dynamic process of the crust fault zone,and the evolutionary research field of the crustal surface catastrophic system.The main achievements of the thesis are as follows:(1)The significant control of the fault zone on both sides of the crust rock mass structure is limited to a certain range and has significant zonal distribution characteristics.Based on the research results of the rock mass density and cumulative density curves,the rock masses with strong fault movement range are obtained.From the fault zone to the two sides,it can be divided into “crack rock zone,strong fault rock zone,and ruptured rock zone”.The classification of two rock belts-the results of zoning research.The width of the upper impact zone of the central fault zone is 3034.0m,of which the crushing rock has a width of 226 m,the strong fractured rock has a width of 1148 m,and the broken rock has a width of 1360 m.The strong influence of the lower part of the Central Fracture Zone is significantly smaller than that of the upper plate,and its width is only 1174.0m.The effect of the upper and lower discs is very significant.The width of the upper structural rupture zone of the Qianshan fault zone is 1352.0 m,which is obviously smaller than that of the central fault zone.As the secondary fault passes through the area,the joint density of the rock mass increases significantly,and the cumulative density increases rapidly.(2)Using Benoit and PCAS software to calculate the fracture fractal dimension and fractal dimension of rock mass.The fracture fractal dimension is between 1.1 and 1.5.Before and after the 32 nd point,both the fracture fractal dimension and the fractal dimension are descending,and the trend is sharply increasing.At the 46 th,the fractal dimension of the fracture fractal dimension and the fractal dimension is sharply decreased.The density curve maintains consistent variability.In terms of fractal dimension,the fractal dimension at point 18 decreases sharply.This area is the area of the fracture zone below the central fault zone.At point 3,the fractal dimension rises and it enters the area of the rupture zone of the Qianshan fault zone.Secondary fault development has a greater impact on the fractal dimension.The more broken the rock mass,the greater the density of joint fractures,the larger the fracture fractal dimension,and the greater the fractal dimension of block size,and vice versa.(3)There is a certain correlation between the fractal dimension and energy of rock mass,and its mathematical model formula is y=0.297x+1.899,and the energy density of rock mass changes with the distance from the front mountain fault zone,showing certain peaks and valleys.feature.In the area where the fault zone passes,it shows peaks and a high energy density.The energy release from the central fault zone also has a typical "hanging effect." After passing the secondary fault,the energy density of the rock mass is also high.The energy of the rock mass in the fracture zone is partitioned on the section and is divided into 5 energy concentration areas: Zone 1(No.1-3)is on the front mountain fault zone.In areas with higher disk energy,Zone 2(points 4-6)and 3(points 9-13)are high energy distribution areas caused by secondary faults,Zone 4(point 18-central fault zone)In the high energy region of the plate rock mass under the central fault zone,Zone 5(central fault zone-point 47)is the energy concentration area of the plate rock mass in the central fault zone.The plane also has the same distribution characteristics.(4)The energy partition of the Yanmenshan fault zone(Qingping section)and its coupling with geological hazards are mainly reflected in two aspects.1)In terms of regional rock mass energy characteristics and regional statistical laws of Wenchuan Earthquake disasters,oversized landslides are mainly distributed in the 5th zone(high energy value zone of the central fault zone);large landslides are mainly distributed in the high energy value regions of each rock mass.,accounting for 67% of all large-scale landslides in the study area,of which 54% of large landslides are distributed in the 5th area;in the aspect of medium-sized landslides,they are mainly distributed in the high-energy area of the upper plateau of the central fault zone,and the high energy value of sub-faults in the 3rd area.District,District 4 The central plateau fault zone has a high energy value in the lower plateau,accounting for 19%,17%,and 14% of the total number of medium-sized landslides in the study area;for small-scale landslides,it mainly concentrates in the 5th zone(high energy in the upper plateau of the central fault zone.(Value Zone): After the 5th Zone,the central plateau fault zone has an upper plateau energy low value zone,the central fracture zone has a lower plateau energy high value zone(4 zones),and the 2nd zone to the 3rd zone energy low value zone accounts for all small scales in the study area.The number of landslides is 33%,24%,14% and 10%.2)Based on the basic information of large-scale landslides with an area of more than 50,000m2 in the Wenchuan earthquake area in the study area obtained by remote sensing interpretation.There are 16 large-scale landslides in the study area,among which 11 are located in high-energy areas of the rock mass(accounting for 68.75% of the total large-scale landslides).Overall,there are 14 large-scale landslides with more than one million square meters,11 of which are located in the high-energy release area of the Longmenshan fault zone,accounting for 78.6% of the total large-scale landslides.The typical Xiaotianchi landslide and Wenjiagou landslide are exceptionally distributed in the low energy release area of the Longmenshan fault zone.(5)For the coupling calculation of typical monolithic earthquake landslide energy and regional rock mass energy characteristics,the initial velocity(starting)data of a typical monolithic landslide is collected to calculate its initial kinetic energy,and the initial kinetic energy of Daguangbao landslide(13.2j)./kg)accounts for 6.6% of the total energy(200j/kg)of the ruptured mountain.Similarly,the initial kinetic energy(11.53 j/kg)of the Wenjiagou landslide accounted for 38.4% of the total energy(30j/kg)of the mountain,and the initial kinetic energy of the Tianchi landslide(2.67 j/kg)accounted for 70.2% of the total energy of the mountain(3.8 j/kg).