Identification and Modeling of Earthdam Response During Northridge, January 17, 1994 and Previous Earthquakes

在1994年北岭地震震中半径50英里范围内的8座仪器齐全的土坝上和周围记录了9416248次埃尔伽马尔地震的加速历史。这些大坝在1971年的圣费尔南多地震和1987年的惠蒂尔地震中也遭受了强烈的地面震动。目前已有大量有价值的输入和响应加速度历史数据集(北岭、惠蒂埃和圣费尔南多地震)，用于校准和验证简化和复杂的计算分析程序。过去对圣费尔南多和惠蒂埃记录的加速度的分析极大地促进了我们对土坝地震响应机制的理解；这些贡献只有通过分析实际的全尺寸地震响应才可能实现。最近恢复的北岭加速历史提供了一个独特的机会，可以在早些时候对圣费利西亚、布丁斯通、科格斯韦尔和布雷亚大坝进行的彻底研究结果的基础上再接再厉。本项目的目标是：(1)使用早先从圣费尔南多和/或惠蒂埃地震中确定的动力特性对每个大坝进行预测性(A/B级)计算分析；(2)鉴于新获得的北岭数据集(具有不同的震动幅度和频率内容)，对以前确定的土坝特性进行严格评估；(3)定义简化的分析/设计程序，并清楚地确定任何相关的限制和/或强度；以及(4)以数据库的形式记录已确定的特性，其中包括加利福尼亚州北部的大量现代土石坝(列克星顿、安德森和长谷大坝)，南加州(Santa Felicia、Puddingstone和Brea大坝)和墨西哥(La Vilita和El Infiernillo大坝)。***

9416248 Elgamal Earthquake acceleration histories were recorded on and around eight well instrumented earth dams within a 50 mile radius of the 1994 Northridge earthquake epicenter. These dams were also subjected to strong ground shaking during the 1971 San Fernando, and the 1987 Whittier earthquakes. A large data set of valuable input and response acceleration histories is currently available (Northridge, Whittier, and San Fernando earthquakes) for calibration and verification of simplified as well as elaborate computational analysis procedures. Past analyses of the San Fernando and Whittier recorded accelerations have significantly contributed to our understanding of earth dam seismic response mechanisms; contributions which were possible only through analyses of actual full-scale seismic response. The recently recovered Northridge acceleration histories offer a unique opportunity to build on the results of thorough studies conducted earlier for the Santa Felicia, Puddingstone, Cogswell and Brea dams. The objective of this project is to: (i) conduct a predictive (Class A/B) computational analysis for each dam using the dynamic properties identified earlier from the San Fernando and/or Whittier earthquakes, (ii) critically assess the previously identified earth dam characteristics in view of the newly acquired Northridge data set (of different shaking amplitudes and frequency contents), (iii) define simplified analysis/design procedures, and clearly identify any associated limitations and/or strengths, and (iv) document the identified properties in a database form that includes a large number of modern earth/rockfill dams in Northern California (Lexington, Anderson and Long Valley dams), Southern California (Santa Felicia, Puddingstone, and Brea dams), and Mexico (La Vilita and El Infiernillo dams). ***