英文篇名
A Brief Review on the Current Deep Excavation Design Code
作者
謝旭昇、程日晟、歐章煜
關鍵字
深開挖、設計規範、貫入深度
摘要
概括而言,深開挖之設計內容包括擋土系統、支撐系統、抽水系統、安全監測系統及鄰房保護系統,而其設計規範主要依循「建築物基礎構造設計規範」第八章「基礎開挖」之條文。「建築物基礎構造設計規範」自民國九十年頒布實施以來已歷經十個寒暑,其間深開挖之分析、設計及施工水準皆有長足之進步,包括數值分析程式之大量使用,地中壁及扶壁之廣泛應用,以及對壁體變位之嚴謹要求等。但不論深開挖之風貌如何演變,其設計仍須以「建築物基礎構造設計規範」為基準,即便規範內容與理論或實務之發展有所落差。
本文針對現行之深開挖設計規範進行探討,主要著眼於設計理論或實務應用與規範之落差。整體而言,現行深開挖設計規範符合實務須求,較有疑義者可能是軟弱黏土層中擋土壁貫入深度之計算。本文提供一設計案例以說明此疑義,亦簡略說明如何在規範架構內處理軟弱黏土層中擋土壁貫入深度之計算。
英文摘要
In general, a complete deep excavation design includes design items such as retaining wall, bracing system, dewatering system, instrumentation, and adjacent building protection system. By all means, excavation design is to follow the requirements as outlined in Chapter 8 of the "Design Code for Building Foundation" published in 2001. Since then, we have witnessed a major improvement on the practice of deep excavation. Among others, the widespread application of numerical tools, extensive use of buttress walls and cross walls, and a stringent requirement on wall deformation all contribute in shaping a new era of deep excavation. One thing remains unchanged, i.e., the design must follow the code, even if there is a gap between the current practice and design code.
This paper discusses the gap between current deep excavation practice and design code. In general, the design code serves the design needs just well. It appears that the only confusion in using the code is related to the calculation of penetration depth for retaining wall embedded in soft clay. Design case is provided in this paper to exemplify this situation. An approach to resolve this confusion is also proposed, though it has to be emphasized that any approach must comply with the current design code.