為了瞭解分區開挖在深開挖工程對連續壁體變位的影響，本研究利用三向度有限元素軟體PLAXIS 3D(2017)進行模擬分析；首先進行參數研究來瞭解控制分區開挖壁體變形的因素為何，從而得知分區開挖的變形機制。再採用兩個不同的分區開挖案例來分析並驗證分區開挖的變形機制，分別為上海南地鐵站購物中心案及仲盛世界商城案。上海南地鐵站購物中心案從施工開始至結束採用6區開挖且開挖深度為14.7公尺，地層主要由上海軟弱黏土組成；仲盛世界商城案在第一個開挖階段採用周圍11區開挖，開挖深度為14.8公尺，地層也是由上海軟弱黏土所組成。藉由上述的實際案例進行回饋分析，並依據現地監測資料驗證其合理性，由於上述兩案例開挖特性迥異，分區開挖對連續壁變位影響並不相同，本研究藉由分區開挖機制來瞭解其影響原因。
研究結果顯示，分區開挖對連續壁體變位的主要機制為足夠的支撐勁度導致開挖時連續壁體在支撐位置造成旋轉，使得最大連續壁體變形移動至開挖表面的位置。而大部分提出分區開挖效應的文章內，皆是在相同的支撐勁度下比較分區開挖與未分區開挖的差異，由分區開挖機制可得知在相同的支撐勁度下，會因連續壁體旋轉而產生相同的連續壁體變形增量。且因分區開挖之開挖寬度皆不小，使開挖後之開挖區內連續壁體達到平面應變狀態，而使得在開挖區內中央仍然產生大量壁體變形。由研究成果顯示，得知分區開挖並無法有效抑制連續壁體的變形。

The zoned excavation is commonly used to mitigate the impact of deep excavation on adjacent asset. Regardless of its broad application in urban area, the mechanisms of the zoned excavation still remain unclear. The present study aims to identify the key factor dominating the wall deflection by carrying out the parametric study. In addition to that, case study is also performed for verification purpose in conjunction with available field measurement.
It was found that the wall rotation occurs at the slab/support level, where shows the comparatively large stiffness. The maximum wall deflection is, in this case, observed at the excavation surface level. The majority of the existing studies tend to adopt identical support stiffness in regards to wall restraining effects among zoned and unzoned excavation. As a consequence, the maximum wall deflection will be the same. In general, the zoned excavation spans considerably and thus the diaphragm wall reaches plane-strain condition after excavation. A large wall deflection occurs at the center part of excavation zone accordingly. Based on the results observed, the zoned excavation cannot effectively restrain the diaphragm wall deflection.

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