Research For Vegetation Restoration To Shi Ma Highway Slope In High Elevation&Cold Region

In recent years, with the implementation of the western development strategy in our country, during the construction of highway, railway, hydropower project, etc. The frequent excavation of the slope destroy the original vegetation layer and lead to a large number of secondary bare land and soil and water loss seriously, increasing the vegetation degradation of ecosystem. The domestic research of vegetation restoration of the slope in high elevation and cold region is paucity. Therefore, how to quickly recovering ecological environment of the slope excavation of highway in high elevation and cold region and making vegetation of the slope protection need to research and solve immediately.To research for vegetation restoration to slope from highway Shi Ma to Manigange, the study is based on geotechnical engineering, vegetation science, soil science, environmental engineering and other scientific theories, in combination with outdoor investigation and indoor test, investigating soil characteristics and adaptive material of the high elevation cold region, adaptive high elevation seed planting experiment was carried out, and through the numerical simulation of plant root system and analysis to simulate the interaction relationship between the rock and soil mass, and from the engineering geology, slope stability, environmental engineering to research the slope vegetation restoration in high elevation and cold region, finally formed a set of technique for slope vegetation restoration in high elevation and cold region system. Mainly obtain are following results:1) Through field investigation and indoor test, illuminates the Shi Ma highway soil characteristics, puts forward the vegetation protection of "grass-shrubs" combined with planting mode of slope in high elevation and cold region, for the highway provides a scientific basis for vegetation restoration.2) Analysis of the vegetation slope protection theory:Plants have an impact on slope stability, through the stem leaf rainfall interception, by the root system on soil reinforcement. Herbs mainly by the root system on soil reinforcement effect, the more soil contain root, the higher the shear strength and bearing capacity of soil; woody plants mainly by vertical and horizontal root system on soil anchor in root, friction, taproot length similar type binding bolt, will decline in soil thrust to the deep, and transfer of power to the lateral root and lateral root and soil frictional resistance, balance in the soil of thrust, and then work on the slope stability.3) Through the establishment of four calculation model, the numerical simulation method to explore the mechanism and effect of vegetation slope protection. Analysis of interaction with the roots of the herbs and rock and soil, the topsoil of slope and root as the root and soil complex, including root soil as root-soil composite material, analyzed the vegetation slope protection of mechanical effects:plant roots can obviously increase of shear strength of soil slope surface, increase the safety factor of slope. Because the plant roots in the soil, the shallow stratum stress and strain state is change, the level of stress in the soil is reduced, limit the lateral displacement of shallow soil, increase the cohesive force and the surrounding stress of soil, slope stability is improved. Woody roots of the solid earth function mainly through the main root system transfer the stress of the surface soil to the deep soil, and anchoring the deep soil, consistent with the anchoring theory, the anchorage theory applied to the root of the solid earth mechanism analysis is feasible.4) Soil fixation effect of plant roots is mainly in the shallow slope, the deep soil effect is not obvious."Herbs-shrubs" of plant slope protection improve the slope stability is best, only the herbs of plant slope protection effect is second, only the woody of plant slope protection effect is the worst.5) Through design the typical soil slope and rock slope vegetation restoration of Shi Ma highway, Put forward the corresponding construction methods. Wet spraying technology and green basic material spraying technology to Shi Ma highway soil slope and rock slope have better protective effect, is applicable to the high elevation cold region highway slope vegetation protection technology.