论文部分内容阅读
为了满足一般桥梁建设工程对50年超越概率5%(地震重现期975年)和50年超越概率2%(地震重现期2475年)下地震动加速度值的需求,该文以编制《中国地震动参数区划图》的数据为基础数据,计算了50年超越概率2%、50年超越概率5%和50年超越概率10%这3个概率水平下的谱加速度值(T=0.0s、0.2s、0.3s、1.0s),统计了50年超越概率2%谱加速度和50年超越概率5%谱加速度分别与50年超越概率10%谱加速度的比值在基岩场地和中硬场地条件下的均值及方差。结果表明:50年超越概率2%水平下的地震动加速度值与50年超越概率10%水平下的地震动加速度值之比的均值在基岩场地下为1.78~2.11,在中硬场地条件下为1.70~1.79;50年超越概率5%水平下的地震动加速度值与50年超越概率10%水平下的地震动加速度值之比的均值在基岩场地下为1.31~1.42,在中硬场地条件下为1.29~1.37。由于土层放大的非线性效应,中硬场地条件下比值的均值比基岩场地条件下稍小。利用K-S检验,发现比值可近似看成符合正态分布,因此可以使用比值的均值来换算50年超越概率2%和50年超越概率5%下的地震动加速度值。
In order to meet the demand of general bridge construction projects for the acceleration of earthquakes with a probability of 5% over 50 years (975 years of seismic recurrence) and 2 years of overrun of 50 years (2475 during seismic recurrence) (T = 0.0s, 0.2) at the three probability levels of 50% exceed probability 2%, 50 years exceed probability 5% and 50 years exceed probability 10% s, 0.3s, 1.0s), the ratio of 50% exceedance probability 2% spectrum acceleration and 50% exceedance probability 5% spectrum acceleration to 50% exceedance probability 10% spectrum acceleration was calculated in the condition of bedrock and medium hard field The mean and variance. The results show that the mean of the ratio of the earthquake acceleration at 2 years beyond the 50% probability to the earthquake acceleration at 10% above the 50% probability at the basement field is 1.78 to 2.11. Under the medium-hard conditions From 1.70 to 1.79; the mean of the ratios of the earthquake acceleration values at the 5% overrun probability of 50 years to those of the earthquakes at 10% overrun probability over 50 years was 1.31-1.42 in the basement field, Under the conditions of 1.29 ~ 1.37. Due to the non-linear effect of soil enlargement, the average value of the ratio under medium-hard-field conditions is slightly smaller than that under bedrock conditions. Using the K-S test, it is found that the ratio can be approximated as a normal distribution. Therefore, the mean of the ratio can be used to calculate the value of the earthquake acceleration at 2 years of 50 years and 5 years of 50 years.