Study On Mechanism Of Slope Failure And Anchoring Of Block Cracking Rock Mass Slope Along Ji'an-Dandong Highway

Collapse, landslide, debris flow and other geological disasters are natural disasters which sudden against human security, particularly landslides, widely distributed in China, against a large, serious threat to people's lives and property.Block crack rock mass distribute widely in the nature, and landslides of block crack rock mass slope are also very frequent. With the rapid development of China's national economy, infrastructure such as railway, highway, and hydropower is faster and faster, people will encounter on more and more landslides of block cracking rock slope.The failure mechanism and the mechanism of anchoring of block cracking rock mass slope will be studied on the base of the slopes along Ji'an-Dandong highway in this article.The highway from Ji'an to Dandong is the vital communication line connecting Ji'an city of Jilin Province and Dandong city of Liaoning Province.This rode is in the south of Laoling, belonging to mountain terrain, and near to the geosphere fracture zone of Yalu river,so joints are relatively developed. Since the unreasonable excavation of slopes and the basting vibration during the construction of the highway, a lot of landslides, collapses and other geological disasters have accurred in many places along the road.The failure mechanism of block cracking rock mass slope is put forward, basing on the detailed analysis of engeineering geological conditiongs of the block cracking slopes in the sections of K6+606-K6+646 and K7+920-K8+244 along the road through field investigation, collecting rock samples, geological mapping, prospecting and other means, in addition, the characteristics and analytical procedures of block cracking rock slope are summarized.The physical and mechanical parameters of the slopes have been gained through test method and back analysis, and the geological models and mechanical models have been established, too. In addition, the block cracking rock mass slopes stability of the two sections has been quantitatively evaluated through the limit equilibrium method used widely. Finally, X2 wedge's slide in the section of K7+920-K8+244 is simulated by FLAC3D a numerical simulation software. The failure mechanism of the sliding wedge is vertifide furture.The prestressed anchor is a very effective treatment measure in the block cracing rock mass slope which is mainly damaged along weak structural planes. Bolt support is an active support, and it disturbs the rock mass little.Slope reinforcement whit bolts, not only occupies less, which is safe and reliable, but also can make full use of the self-bearing capacity of the rock mass. Moreover, it can accelerate construction progress and reduce project cost.Therefore, anchor support is more and more widely used in the block cracking rock mass slope.The anchoring mechanism and the various factors affecting the anchoring effect have been analysed on the base of the failure mechanism of block cracking rock slope and rock anchoring principle in the paper. The principles of anchor design have been put forward. Combined with anchorage design principles and methods, the anchorage design of K6+606-K6+646 and K7+920-K8+244 sections'block cracking rock mass slopes has been made, according to the slopes'stability,terrain conditions, the scale and potential landslides damaged surface,etc.Finally,the numerical simulation of the anchoring effect has been made too. The anchoring mechanism of the block cracking rock mass slope is analysed futher by comparing the different anchoring effects in different anchoring angles, different bolt lengehs.