| With the development of economy of China these years, demands forresource and energy growing more and more, construction of civil engineering isdeveloping quickly as a high speed what never have, for those projectsconstruction action, it is unavoidable for us to meet large of excavation ofrock-soil mass, the large number of slopes appear. The slope height became higherand higher with the project scale's increasing continually, so the stability analysisand geologic tragedy treatment for the high slope turn into the key part ofengineering safety. At the same time, it took a controlling act on the feasibility,security and economy of the whole engineering construction, once treatingimproperly, the slopes would produce landslide and collapse, etc. geologicaltragedy, and result was very serious unimaginably.Traditional disaster evaluation and treatment design of slope based onstrength stability theory and limiting equilibrium theory of statics mostly,designing ideology present shortcomings as following: ①Based on the limitingequilibrium theory of soil mechanics, suppose rock-soil mass consist of someuniform rigid mediums, searching failure face simply. It be far away from theactual condition that most of slopes primarily be under controlling of structuralplane of rock mass. ②The traditional limiting equilibrium method founded on thebase of determinate failure face to calculate the safety factor without thinking ofmutual action between rock-soil and supporting structures. Therefore, this paperbased on the traditional theory to build the research method of "dynamicsimulation process and controlling" with thinking of mutual action betweenrock-soil mass and support structures. The research had been carried out for thestability and support design plan of slope in site.This paper selected the representative rock steep slopes in liquefied naturalgas site in Guangdong as a research object. With field survey and inspection overhalf year on site, after obtaining the geology material of slope, the ample study forthe joint and fissure planes of slope B had been carried out, and adopting thestereographic projection to analyse the the local stability of excavation slope B insite, so the overall stability of excavated slope was on the basis of those mentionabove. At same time, the rock mass strength parameters had been determinedaccording to the Hoek-Brown empirism criterion and empiristic methods. Usingthe Janbu method to analyze the stability for the 7 slopes, and adopted the FLAC2D finite difference method to analyze slope B with the most large-scaled, highestand most complicated geology structure. Put forward the supporting design andchecked with limited equilibrium method, and analyzed the design plan of slope Bwith FLAC-2D method after researching the anchor mechanism of anchor boltsand anchor cables, in contrast with the result of limited equilibrium method tocheck the reasonability and feasibility of design plan.We get some cognition as following during the research,⑴ The rock parameters should be gotten after integrative contrast on thebasis of combination between the theory and experience on site, for it is key pointwhether the stability result was correct.⑵ Many kinds of theory appeared on the anchor mechanism at present,but under all kinds of influence of geology factors, the real anchor mechanism has not been completely simulated yet, and wait and need the further study on it.⑶ being in contrast to the limited equilibrium method, FLAC can reflect thedeformation process better in dynamic, considering the stresses reduce andredistribution when executed stability calculation, and thinking the tension stresssoften of rock mass, so the analysis result can be more exact.
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