由大岡山北嶺加壓站配水池工程模板支撐倒塌檢討棚架式模板支撐組搭之安全

Safety Investigation of Framed Falsework Based on Falsework Collapse of Ta-Kang-San Reservoir

中高挑空鋼筋混凝土建築，常基於成本考量採用棚架式組搭模板支撐系統，民國 86 年 12 月 13 日高雄縣岡山鎮北嶺加壓站配水池工地採用此種模板支撐，於灌漿時發生倒塌，造成國內近 30 年來營建工程最嚴重的倒塌意外。本文藉由此事件檢討棚架式組搭模板支撐的安全性，分別從結構極限強度及工程實務兩方面來探討。研究結果顯示，由於國內模板支撐設計規範的不足，設計師缺乏可供設計參考的依據，現階段工地模板支撐，宜以現有組搭進行結構非線性分析來確認強度。此外由於模板支撐結構圖及施工圖繪製的不實，致使工地施工完全以經驗為主，有必要儘速建立結構圖及施工圖的制式流程，供施工單位遵循。為確保結構設計與工地現場使用構材的吻合，構材品質的檢驗亦需檢討。

In median and high headroom reinforced concrete buildings, frame-type falsework is used as a temporary structure based on the reason of economical consideration in construction. A serious collapse of the frame-type falsework occurred during placing concrete at Ta-Kang-San reservoir, Kaushung, on December 13, 1997. This collapse is the most serious accident during construction in the last 30 years in Taiwan. This paper investigates the safety of the frame-type falsework based on the critical load and the engineering practice. Owing to the lack of specifications and standards of falsework design, engineers rarely have a good design for the falsework. The current verification of the structural strength of the falsework is suggested to directly analyze the falsework by a second-order elastic analysis. Besides, the flowchart of the structural and constructional blueprints should be setup. The workers rely on their experience to conduct the falsework due to the lack of the blueprints of the falsework. In order to make sure the coincidence between the design and the material of falsework, the inspection system should be established.