The Project Optimization Of Zhaisuo Landslide Prevention Engineering

With "the great development of the west" strategy gradually thorough, more and more high-grade highway extends to the area of loess gully, tableland, beam and replat, causing a greater amount of geological hazards problems, landslide is the most common and also the most harmful kind. In order to avoid and reduce the loss of economy, life and property which caused by landslide to the people and society, further study of the effective and economy landslide prevention scheme has important significance. This paper take the Zhaisuo landslide that next to the national highway NO.312 as the research object, by analysis the basic characteristics, factors of deformation and destruction, summarize the current landslide prevention principle, thinking and measures, drafted the landslide prevention scheme, study the concrete prevention measures’ optimizing factors, finally, determined the optimal Zhaisuo landslide prevention scheme, obtained some valuable conclusion.(1)Put forward the prevention principle and thinking of the landslide; drafted three sets of prevention schemes: scheme 1: shave the slop to reduce the weight+intercepting drain, drainage ditch+greening; scheme 2: anti-slide pile/anti-sliding retaining wall+intercepting drain, drainage ditch+greening; scheme 3: anti-slide pile/anti-sliding retaining wall+shave the slop to reduce the weight+intercepting drain, drainage ditch+greening. By the comparison and selection, decide use the scheme 3 to govern the Zhaisuo landslide.(2)Propose the pattern, height and ratio of slope as the optimizing factors of the “shave the slop to reduce the weight” measure, and by means of Flac3 D to modeling and analysis, obtain the relationship between the stability coefficient and the height and ratio of slope of the Zhaisuo landslide which is K=-0.2929i-0.01h+1.56.(3)Propose the pile section, pile length, anchorage depth and the pile spacing as the optimizing factors of the “anti-slide pile” measure, through the Flac3 D to modeling and analysis, get the relationship between displacement of pile top and the optimizing factors:1) the maximum displacement of pile top decreases with the increasing of pile’s section area. When the section area is 1.5×2.5m2、2×2.5m2, the maximum displacement of pile top’s variation range 1.85×10-4m and 0.76×10-4m, when the section area increase to the 2×3m2, 2.5×3m2, 2.5×3.5m2, 3×3.5m2, 3×4m2, the maximum displacement of pile top change slightly, the variation range 0.03×10-4~0.09×10-4m.2) the maximum displacement of pile top decreases with the increasing of anchorage depth. When the anchorage depth is 2m, the maximum displacement of pile top is 9.65×10-4m, the displacement difference to the 3m(one third of the pile length) is 0.48×10-4m, when the anchorage depth increase to the 3m, 4m, 5m, the adjacent displacement difference are only between 0.01×10-4m and 0.05×10-4m.3) the maximum displacement of pile top decreases with the increasing of pile length. When the pile length is 8m, the maximum displacement of pile top is 9.13×10-4m, the displacement difference to the 9m is 1.57×10-4m; when the pile length increase to the 9m, 10 m, 11 m, the adjacent displacement difference are only between 0.11×10-4m and 0.35×10-4m.4) the maximum displacement of pile top increase with the increasing of pile spacing. When the pile spacing is 6m, 7m, 8m, 9m, the maximum displacement of pile top are between 0.03×10-4m and 0.09×10-4m, when the pile spacing increase to the 10 m, the maximum displacement of pile top increase to the 0.26×10-4m quickly.The anti-slide pile’s safety and stable layout conditions of Zhaisuo landslide is : pile section take 2×3m, anchorage depth take 3m, pile length take 9m, pile spacing take 9m.