This paper presents the case study of the staged excavation for the New York University College of Nursing building in Manhattan, NY, supported by corner-braced secant pile walls. A commercial finite-element software was used to simulate the complex supported excavation and predict the retaining wall deflections using simple soil models calibrated from limited soil data. The results of the two-dimensional (2D) simulations were compared with actual wall deflections measured by inclinometers during the excavation process. The aim of this research was to determine whether the complex 3D characteristics of the problem could be captured and accurately simulated by equivalent 2D models, using soil properties estimated from limited field data, which is typically the case in engineering practice. Equivalent axial and bending stiffnesses were also estimated for simulating the square bracing system in plane-strain conditions. The numerical analyses yielded results that correlated with the measured data which indicates that – for this type of excavation problem – simplified plane-strain analyses can predict sufficiently small wall movements, given that appropriate stiffness magnitudes are assigned to the earth-retaining system.

中文翻译：

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纽约曼哈顿的挖掘案例研究，采用实用方法预测地面运动

本文介绍了位于纽约曼哈顿的纽约大学护理学院大楼的分阶段开挖案例研究，该大楼由角撑割线桩墙支撑。商业有限元软件用于模拟复杂的支护开挖，并使用从有限土壤数据校准的简单土壤模型预测挡土墙挠度。将二维 (2D) 模拟的结果与挖掘过程中由测斜仪测量的实际墙体挠度进行比较。本研究的目的是确定问题的复杂 3D 特征是否可以通过等效的 2D 模型捕获并准确模拟，使用从有限的现场数据估计的土壤特性，这在工程实践中是典型的情况。还估计了等效的轴向和弯曲刚度，以模拟平面应变条件下的方形支撑系统。数值分析产生的结果与测量数据相关，这表明 - 对于这种类型的开挖问题 - 简化的平面应变分析可以预测足够小的墙体移动，前提是为挡土系统分配了适当的刚度大小。