Time-domain identification of dynamic properties of layered soil by using extended Kalman filter and recorded seismic data

A novel time-domain identification technique is developed for the seismic response analysis of soil-structure interaction. A two-degree-of-freedom (2DOF) model with eight lumped parameters is adopted to model the frequency-dependent behavior of soils. For layered soil, the equivalent eight parameters of the 2DOF model arc identified by the extended Kalman filter (EKF) method using recorded seismic data. The polynomial approximations for derivation of state estimators are applied in the EKF procedure. A realistic identification example is given for the layered-soil of a building site in Anchorage, Alaska in the United States. Results of the example demonstrate the feasibility and practicality of the proposed identification technique. The 2DOF soil model and the identification technique can be used for nonlinear response analysis of soil-structure interaction in the time-domain for layered of complex soil conditions. The identified parameters can be stored in a database for use in other similar soil conditions. If a universal database that covers information related to most soil conditions is developed in the future, engineers could conveniently perform time history analyses of soil-structural interaction.     

浅析《鄞州区社区地图集》的设计与编制

在城市发展建设过程中,各种地理要素、社会要素不断更新、变化,最终可以地图的形式反映出来。编制鄞州区社区地图集,可以将鄞州区内各社区发展建设的详细情况,清晰、直观地展现给读者。本文通过梳理鄞州区社区地图集的设计编制过程,浅析地图集编制的关键技术和编制特点。     

浅谈鄞州区基础地理信息系统数据库更新的方法

鄞州区基础地理信息系统数据库涵盖了基础地理信息数据库、遥感影像库、地名库、地下管线库等,通过对各类数据库中的数据更新,全面提升鄞州区的基础测绘信息化水平,为鄞州区的地理信息公共服务保驾护航。本文通过对鄞州基础地理信息系统数据库中各类数据及其更新技术路线的梳理,浅谈数据库更新的方法。