近接浅基础建筑物深基坑变形特性及关键参数

基于现场实测数据和数值模拟对深基坑围护结构和既有建筑物的变形特性进行了研究.采用有限元方法建立数值计算模型，结合现场实测数据和已有文献对邻近既有建筑物深基坑开挖变形规律进行参数分析，全面揭示了不同工况下围护结构变形与建筑物沉降的关系.结果表明:桩锚支护结构在锦州地区深基坑应用效果较好，控制变形能力强;矩形基坑的坑角效应显著，坑角处平面应变比(PSR)值约为0.4~0.6;建筑物基础埋深和基坑开挖深度对建筑物平均沉降(δ_va)与围护结构最大侧移量(δ_hm)的线性关系影响不大;建筑物与围护结构距离L不同时，δ_va与δ_hm数据离散性较大，随着L的增加，δ_va/δ_hm逐渐减小.

Deformation Characteristics and Key Parameters of Deep Excavation Adjacent to Buildings with Shallow Foundations

Based on the in situ observation and numerical simulation， the deformation characteristics of the retaining structure of a deep excavation and the existing building were investigated. According to the in situ observations and available literatures， parametric studies were conducted using FEM to investigate the deformational behaviors of the excavation adjacent to existing building. The relationships between the deformation of the retaining structures and the settlement of the adjacent building under various construction conditions were fully revealed. Results showed that the tieback anchored pile wall has a good deformation control capacity and can be applied effectively in Jinzhou area. The corner effect of the rectangular excavation is significant with a plain strain ration (PSR)of about 0.4~0.6.The linear relationship between the average building settlement (δ_va) and the maximum horizontal deformation of the retaining structure (δ_hm) is slightly influenced by the existing foundation depth and the excavation depth. The discreteness of δ_va and δ_hm appears when the distance between the building and the retaining structure (L) changes， however the δ_va/δ_hm decreases gradually with the increase of L.