Research On The Stability Of Building Rock Slope And Its Control

Rock slope is a common type in practiced projects such as mountain city construction, road, railway, water conservancy, mining engineering and national defense. With development of city construction, more and more problems appear in building rock slope. Although building rock slope is not too large in dimensions, it plays an important role for main body of whole construction in argumentation of feasibility, economic guideline, normal operation, etc. It must be mentioned here that instability of slopes due to lack of cognition about failure mechanism of construction rock slope has resulted in huge loss for nation and people, whereas reasonable design and support of slopes evidently benefit people. Therefore, it is necessary to research deeply the stability of rock slope and its control. Stability of building rock slope with relatively intact texture and its control are studied deeply in the paper. The significant results are obtained, and the results are applied to actual rock engineering, the prominent economic and social benefits are attained. Main points are shown as follows: (1) The method to determine unloading mechanics parameters of the slope rock mass is established. Combining field test and theoretical analysis, the mechanism of occurrence, development and destruction of rock slope's gradual failure have been studied. Based on unloading nonlinear rock mass mechanics, unloading zone on the top of slope is defined. The distribution law of wall pressure in rock slope and the corresponding calculation formulas are given. (2) A new idea of "information control on complete process"to stability of building rock slope is brought up by analyzing traditional slope timbering design against ultimately efficient slope stability. The basic theory of the new idea and the structure of three dimensional control systems are also expounded. (3) Combining the research practice on building rock slope, stability control on building rock slope is studied. At the same time a series of comparative perfect technology systems of stability and its control of construction rock slope are established. A control scheme of anchoring crucially the key body of slope top for construction rock slope without extroversion is proposed. Reliability and advantage relative to general scheme of this scheme are validated by using numerical analysis and slope monitoring at the stage of construction and completion. (4) Based on successful conclusion of Guihuayuan subzone project, one of reconstruction projects of old city in Yuzhong District, Chongqing, the synthetical analysis method about whole stability of slope and building foundation on the top of slope is provided while researching construction of tall building on the top of slope. The process of deformation and failure are simulated when tall buildings are built on the top of slope. Security judgments about slope and building foundation on the top of slope are determined. (5) Through analysis on stress distribution in the foundation on the top of slope, the ways to determine the subgrade bearing capacity of building on the top of slope are proposed, based on uniaxial compressive strength on the condition of natural moisture. Combining design of building foundation on the top of slope and design of prevention projects for slope, by analyzing on these factors which affect on building on the top of slope and whole stability control of slope, the scheme is brought up ,namely "人"shaped anchor used for controlling the monolithic stability of buildings on the top of slope and the slope. (6) According to field test and theoretical analysis, the difference of mechanisms and distributing behaviors of shear stress between pressure-type and tensile-type anchor are analyzed. Distributing behaviors of shear stress with hyperbolic function in the pressure-type anchor is established. Failure mode of pressure-type anchor in rock is proposed, and design formula and the corresponding parameter of pressure-type anchor are determined in accordance with three failure modes. Moreover, the advantages of pressure-type anchor applied in building rock slope project are sum up.