Optimization Selecting Of Protection Technique And Plant Species With Vegetation-growing For Cracked Rock Slope In Highwa

China leave lots of rock slope due to the excavation for highway construction, in the past most of it were protected with mortar-rubble skeleton, arch skeleton, etc.,which is effective measures in the era of lacking awareness of ecological and environmental. But with the economic development and the increasing requirements on the environment, the ecological protection of rock slope in the highway Domain has become an urgent problem.Because of fissure development in craked rock slope of highway, we can neither apply the vegetation protedting method of soil slope nor differ from intack rock slope.It is key to select the technique of fixing soil and plant species when protecting cracked rock slope with vegetation-growing. Based on a brief introduction of main protecting technique for rock slope with vegetation-growing, through investigation of95engineering construction cases, the technique of fixing soil suitable for cracked rock slope-3D geomat, geocell, mixed sprinkling planting and diamond wire netting were elected and describe its construction technology. According to the mix-sowing technology for plant diversity, author put forward the application of allelopathy (promoting and constraining mutually)in plant species selection for slope vegetation protection and summarize the allelopathic plants relating to slope vegetation protection.In order to assess the effects of fixing soil technique selected for slope protection with vegetation-growing, confirm the presence of plant allelopathy(promoting and constraining mutually), the test was made at the site of a cracked rock slope in the south with the strengthening structures of geocell and diamond wire netting, through selecting4kind of herbaceous plants in cold season and warm season.The test results indicate that:no matter the grass growth, green coverage of slope side or landscape slope, the effects of geocell on its various aspects are better than diamond wire netting,cool season grass such as Tall fescue(Festuca arundinacea) and White Clover (Trifolium repens),and warm season grass such as Bermuda Grass (Cynodon dactylon) and Bahia grass(Paspalum natatu) can be mixed seeding to the slope, both of them were able to complement each other very well, and had a good adaptability to the geological conditions and the soil of the slope,its root system differing in length plays the support role to different depth of slope in forming a stable layer of defense, so as to be protected all the year round. In order to verify the stability of slope protection with vegetation-growing, the behavior of geocell and3D geomat under load was analyzed with3D-σ software.The results of analysis show that the geocell increase the strength of filled soil and the ability to resist deformation of retaining structures significantly, even if the slope face exerts additional load of10N/m2, it is still stable, satisfies the requirements of filled soil perfectly. The effect of3D geomat is similar to geocell, the self weight of topsoil and mat is passed to the rock slope through the anchor, and also meet the requirements of fixing soil.