Study On The Mechanism Of The Flat Push Red Bed Landslide Based On The Analysis Of Creep And Softening Characteristics

Red layer horizontal push landslide is widely developed in the southwest region of the red layer to a Class ANGLED Rock-based landslide, characterized in that the strata dip only 2 ~ 5 °, often developed in the sand, shale interbedded stratum structure in. According to the conventional limit equilibrium theory, this type of landslide is difficult sliding, there is some controversy on the genetic mechanism of such landslides different scholars. Therefore, this paper Xinjin County Shizishan mountain landslide detailed study of the causes for such landslide mechanism, monitoring and early warning, prevention and treatment project is of great significance. Through the introduction of the landslide area location, meteorology, hydrology, topography, lithology, geological structure and seismic, hydrogeological, and other aspects of human activity, clarified Natural geography and geological environment in which Shizishan mountain landslide condition.On the basis of a large number of field investigation, combined with a wide range of data collection, the work of the relevant literature review, analyzed the geological environment and the basic characteristics of the landslide landslide. Softened by performing experiments with soil slip, slide zone soil creep tests, experiments softened mudstone, mudstone creep experiments slip band soil and overburden soil water characteristic experiment, detailed analysis of the physical properties of the material composition of the landslide. And on this basis, the system analyzes the genetic mechanism Shizishan mountain landslide, seepage field characteristics, stability characterized by theoretical analysis and numerical simulation method of combining. The main contents and results are as follows:(1) Through the field investigation, the engineering geological condition and geological environment condition of the lion mountain landslide are found out. The lion mountain landslide is a typical shallow hill landscape development in the hilly area of Xinjin County, long Akiyama in the Upper West side. The terrain in the rear of the landslide is in a funnel shape. Characteristics of multi- flood in summer. Lithology is mainly Cretaceous Series clamp Guan Qun(k2j) sandstone, mudstone and Quaternary loose rocks, with characteristics of sandstone and mudstone interbedded, terrane 25 ~ 40 degrees was 3 ~ ~ 6 degrees. According to the characteristics of landslide deformation, the deformation can be divided into three parts: the west side of the shear failure zone(zone I), the central plain pushing forward area(II), the weak deformation zone on the east side(III).(2) by softening experiment mudstone and sliding soil found: mudstone and sliding zone soil at a lower moisture content, the higher shear strength; with the increase of time soaked in water, the moisture content of the sample increases, slip with soil and shale strength decreases rapidly. Combined with field investigation found that the landslide slope with good catchment conditions, landslide pull stuck groove in front of the landslide damage has good water conditions, water can trap groove oozing slowly along the slippery surface by pulling for the slip surface and mudstone slip zone softened soil provides sufficient water conditions and time conditions.(3) by mudstone creep experiments and sliding soil found: Comparison of Experimental and softened mudstone sliding soil, at the same moisture content, long-term creep strength is further reduced than triaxial strength, has made experimental parameters for the analysis of landslide long-term stability to provide effective data support. Combined with the landslide evolution process analysis, historical evolution, the slide in the long term with a landslide soften and creep characteristics of their own role in groundwater, shear strength index and mudstone sliding soil further weakened. Further, since the slide with mudstone and sliding zone soil located near the level of development of the sandstone bedrock by drilling survey and found that the integrity of the bedrock of good, poor permeability, so that the sliding band is under long-term ground water immersion, with the slide the slippery and creep provide strong material conditions.(4) by sliding zone soil and overburden soil water characteristic curve experiment, to give both the SWCC, import Geo-Studio of Seep / W module, Landslides seepage, percolation characteristics obtained landslide. Further confirms the Landslide Seepage Field site survey results. With Slope / W combined with the calculated data Seep / W, and analyze the stability of the landslide, the results show that: the stability of the landslide in the water tank with pull-notch height increases, further reducing the stability factor; when the water tank pull trap when the height reaches a critical value, the landslide instability failure under the action of hydrostatic pressure and uplift pressure.(5) the whole process of evolution combined with the landslide analysis, the causes of the landslide mechanism is divided into three parts:(1) bred mechanism landslide: including material basis, structure transformation, epigenetic alteration, which ultimately determines the impact of internal geological landslide external factors and incentives; daily landslide deformation mechanism(2): after forming a natural slope, landslide deformation evolution began in everyday situations, mainly divided into uneven unloading rebound phase, slip- pressure-induced crack surface bottom-up expansion phase, slip plane through the destruction phase, slip plane through the destruction stage;(3) sliding failure mechanism of landslides: flat push landslide mainly daily deformation process of gradual accumulation, the last stage is the damage after the landslide deformation accumulation final flashpoint, eventually leading to the destruction of landslides; landslide destroyed before sliding surface has been formed, the sliding surface along pull trapped weak slotted at the bottom of the gradual development, and ultimately provide the impetus for the destruction of the landslide is pulling notch groove hydrostatic pressure and substrate uplift pressure the joint effect of both landslides final push flat damage.