边坡岩石块体动力响应和锚固抗震效应研究.pdf

27 3 Vol27 o3 2010 3 Journal of Highway andTransportation Research and Development Mar 2010 :(2010) 王 建, 姚令侃, 蒋良潍 ( , 610031) : 为研究路堑岩质边坡的抗震设防问题, 在对汶川地震震区公路沿线岩质边坡进行震害调查的基 上, 以川藏公 路沿线某处典型岩坡为例, 结合块体理论分析和动力数值计算, 对边坡岩石块体的地震动反应特性及块体锚固效应进 行研究结果表明: 节理会造成加速度的显著放大, 未锚固的楔形块体加速度放大系数比完好岩体大 3倍; 锚固后, 加速度放大系数比锚固前减小了30% 频谱分析表明, 节理面降低了岩体的整体性, 提高了地震动放大的幅值, 扩大 了加速度放大的频率范围, 并使自振频率接近地震波的主频, 从而增强了块体的地震动反应强度; 锚固使节理岩体的 自振频率远离地震波的主频, 降低了节理面附近岩体响应加速度的幅值, 从而提高了岩体的抗震能力 : 道路工程; 抗震设计; 动力计算; 岩质边坡; 频谱分析 : P31596 : A Research on Dynamic Response of Rock Blocks in Slope and Anti seismic Effect of Anchor Reinforcement to Rock Mass WA G Jian, YAO Lingkan, JIA G Liangwei (School of Civil Engineering, Southwest Jiaotong University, Chengdu Sichuan 610031, China) Abstract: To research the antiseismicbehavior of rock slope along cutting of highway, on the basis of field inves- tigation on the damages of rock slopesof highway inWenchuan seismic area, sometypicalslope along SichuanTibet highway was taken for example to explorethe seismic response behavior and anchorage effect of slope rock mass by combing block theoretical analysis with dynamicnumerical calculationIt shows that ( 1) joints may cause significant amplification of seismicmotion, enhancethe amplitudeof the earthquake motion and makethe natural frequency of rock mass close to that of seismic wave with acceleration amplification factor of unanchored wedged block mass 3 times larger than that ofwholesomerock mass; (2) acceleration amplification factor of anchored wedged block mass will decreaseby 30% tothat of unanchored wedged block massAccording to spectrum analyticresult, thefrequ