板布河大桥百米级高陡岸坡稳定性研究

Study on Stability of Banbuhe River Bridge 100-Meter High and Steep Bank Slope

新建板布河大桥为瓮马铁路南北延伸线的控制工程,为188m上承式钢筋混凝土铁路拱桥;大桥跨板布河深切V型谷,两岸岸坡陡峭,岸坡高达105116m,超过百米,地层为第三系(E)巨厚层状钙质角砾岩,弱风化,岩质坚硬,两岸岸坡卸荷裂隙发育。通过综合勘察手段查明了板布河大桥场区工程地质条件,综合多种分析方法对高陡岸坡的稳定性进行分析,通过施工开挖后对边坡进行了再次调查分析,百米高陡岸坡卸荷裂隙发育影响其承载力及岸坡稳定性,应加强施工地质核查工作;并针对计算结果进行了边坡防护设计,采取了锚索、锚杆对板布河大桥高陡边坡进行防护设计,锚索设计锚固力1050kN,可为西南山区硬质岩高陡边坡稳定性分析提供参考。

The newly built Banbuhe Bridge is the control project of Wengma Railway's north-south extension line,and is a 188 m through reinforced concrete railway arch bridge.The bridge spans Banbuhe River and cuts deep V-type valley.The bank slope is steep and the bank slope is 105-116 m,over 100 m.The stratum is of tertiary(E)calcareous breccia with huge thickness,weak weathering and hard rock,the unloading fissures are developed on both bank slopes.The engineering geological conditions at the site of the Banbuhe Bridge were ascertained by means of comprehensive investigation,and a variety of analysis methods were used to analyze the stability of high steep bank slopes.The slope was re-investigated and analyzed after construction excavation.The unloading fissures of 100 m high steep bank slope influenced its bearing capacity and bank slope stability,so the construction geological check should be strengthened.According to the calculation results,the slope protection design was carried out,and the anchor cable and bolt were adopted to protect the high and steep slope of Banbuhe River Bridge.The designed anchoring force of the anchor cable was 1050 kN,which can provide reference for stability analysis of high and steep hard rock slope in southwest mountain area.