扶壁及地中壁間距之效率分析

Efficiency of Buttress Walls and Cross Walls for different Excavation Area in Deep Excavation

林宗毅(Zong-Yi Lin)

指導教授 ： 陳水龍

國立臺北科技大學/工程學院/土木與防災研究所/碩士(2013年)

摘要

台灣深開挖工程多使用地質改良來提升土壤勁度及強度，近年來用扶壁及地中壁取代地質改良。但台灣目前尚無扶壁及地中壁之標準設計規範，只能依靠大地工程師之經驗及數值分析之結果來進行設計。本研究採用「有限元素法」所撰寫之三向度數值分析軟體「Plaxis 3D」，探討扶壁及地中壁之效率。利用實際案例驗證軟體模擬扶壁及地中壁的成果與監測之間是否一致，再針對工程案例之長與寬進行比例縮減，藉此得扶壁及地中壁在不同間距下之行為。
分析結果顯示，使用扶壁及地中壁可有效減少連續壁側向位移及沉陷槽影響範圍，其中以地中壁之影響最為有效，其次是扶壁。壁體間距的改變與減少之位移量有一定關係式存在，根據本研究分析成果呈一線性方程式，連續壁之DRR值與地中壁間距的線性關係為y= -30.855x+93.802。連續壁之DRR值與扶壁間距的線性關係為y= -30.725x+67.065。連續壁之SRR值與地中壁間距的線性關係為y= -21.251x+97.807。連續壁之SRR值與扶壁間距的線性關係為y= -32.027x+75.364。研究成果可作為深開挖工程施作地中壁及扶壁設計之依據。

關鍵字

扶壁 ； 地中壁 ； 深開挖 ； 數值分析 ； 連續壁

並列摘要

Ground improvement is introduced in many deep excavations in Taiwan for the improvement of soil stiffness and strength. Buttresses and cross walls are brought in to replace ground improvement in Taiwan in recent years. However, the lack of standard design specifications for buttresses and cross walls in Taiwan forces geotechnical engineers to design them based on experience and numeric analysis results. Plaxis 3D, a 3D numeric analysis program developed based on the “finite element method,” was used to explore the efficiency of buttresses and cross walls. The data gathered from real-life cases were used to verify whether the results of buttresses and cross walls from program simulation were consistent with the monitoring data. The length and width of engineering cases were scaled down to determine the behaviors of buttresses and cross walls with different intervals.
The analysis showed that the buttresses and cross walls were effective in reducing the lateral displacement in diaphragm walls and the influence range of settlement troughs. The cross walls performed better than buttresses. A certain relation was observed between the changes in the interval between walls and the displacement reduced. A linear equation was derived from the analysis results. The linear relation between the DRR value of diaphragm walls and the interval between cross walls was y= -30.855x+93.802; that between the DRR value of diaphragm walls and the interval between buttresses was y= -30.725x+67.065; that between the SRR value of diaphragm walls and the interval between cross walls was y= -21.251x+97.807; and that between the SRR value of diaphragm walls and the interval between buttresses was y= -32.027x+75.364. The results will contribute to the design of buttresses and cross walls used in deep excavations.

並列關鍵字

Buttress Wall ； Cross Wall ； Deep Excavation ； Numeric Analysis ； Diaphragm Wall

參考文獻

20. 王建智、詹勳山、雷一明、謝坤宏，「高雄地區深開挖工程特性與參數回饋分析之研究」，國科會專題研究計畫成果報告，2003。

29. 李崇道，「深開挖之扶壁數值分析」，碩士論文，國立台北科技大學土木與防災研究所，台北，2009。

47. 盧怡志，「影響扶壁及地中壁行為施工特性之研究」，碩士論文，國立台北科技大學土木與防災研究所，台北，2007。

48. 謝旭昇，「逆打臨時支撐之行為研究」，大地工程技術講座，大地工程技師公會，台北，2008。

49. 謝旭昇、呂芳熾，「淺論扶壁式連續壁之分析與設計」，地工技術雜誌，第76期，1999，第39-50頁。