广深港高铁狮子洋隧道列车所致环境振动实测研究

STUDY AND FIELD MEASUREMENT OF ENVIRONMENTAL VIBRATION INDUCED BY UNDERGROUND HIGH-SPEED RAILWAY IN SHIZIYANG TUNNEL

对处于粉细砂地层中的广深港高铁狮子洋隧道内高速列车引起的地面振动进行现场测量,列车速度310 km/h时,隧顶最大振动加速度为10.78 cm/s2,最大振动速度为0.034 cm/s;振动能量均主要集中在60 Hz以内,主频分布于30~40 Hz范围内,振动主频整体上随距离的增加而降低;加速度在30~40 m范围存在明显的放大区。通过类比分析可知轨道系统采用减振垫层后场地振动较小,与低速地铁所致环境振动在同一量级,总体上低于不采取特殊措施的地铁,而略高于采取钢弹簧浮置板轨道的地铁。发现环向、径向振动大于垂向振动的现象,而通常只关注竖直向振动,因此建议注意水平向地面振动对地面目标的影响规律。本文形成了多种条件下高铁经过隧道所致环境响应数据中心,可进行地面响应的多维插值预测;发现用极值I型公式可更好地描述场地振动分布规律,据此可完成更多情况的振动评估。

Ground vibration induced by high-speed train in Shiziyang tunnel which lies in fine sand layer stratum is measured. At the speed of 310 km/h,the maximum acceleration on top of the tunnel is 10.78 cm/s2,while the maximum velocity is 0.034 cm/s;vibration energy is mainly concentrated within 60 Hz,main frequencies are in 30-40 Hz , and the predominant frequency decreases with distance. There is obvious amplification for acceleration in the range of 30-40 m. Analogy analysis shows that by using damping cushion in the track system the environmental vibration is small,and is in the same order of magnitude as low speed subway,lower than that of subway without dumping measures,while slightly higher than that of subway with steel spring floating slab track. In some points,the circumferential and radial vibrations are larger than the vertical vibration,so it is suggested that attention should also be paid to the influence of horizontal ground vibration on buildings beside that induced by vertical vibration. A data center of environmental response induced by underground highs-peed trains is formed,based on it prediction for ground vibration by multi-dimensional interpolation can be executed. A empirical formula of extreme value type is also put forward to describe the ground vibration distribution,by which more vibration evaluation can be accomplished conveniently.