Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/13462
標題: 鋼管架模板支撐系統承載力之探討:地基沉陷及鋼索補強
Study on Bearing Capacity of Steel Scaffold System : Subjected to Base Settlement and Cable Strengthening
作者: 林宏坤
Lin, Hung-Kun
關鍵字: Steel Scaffold;鋼管架
出版社: 土木工程學系
摘要: 
本文主要在探討鋼索補強後, 鋼管架聯合支撐系統之極限載重與破壞
模式, 以及地基沉陷對鋼管架極限承載力之影響。研究內容包括室內試驗
與數值模式分析兩部份, 試驗工作在瞭解鋼索補強後之極限承載力與破壞
模式, 並評估其可行性。另外, 則探討沉陷問題對鋼管架系統之影響。在
數值模式分析方面, 使用ANSYS為分析工具, 依據試驗條件建立數值分析
模式, 與試驗結果比對後, 將其延伸進行參數探討, 以期得到更佳之應用

試驗結果得知, 在鋼管架上搭接木支撐之鋼管架聯合支撐系統, 若使用鋼
索提供鋼管架與木支撐搭接部份之側向位移束制時, 須特別留心鋼索預力
的對稱施加, 與提供鋼索反力束制處之牢固。鋼索補強面在in-plane方
向, 且鋼索與地面夾角為60度時, 預拉力提供220 kgf, 可使此鋼管架聯
合支撐系統之承載力提升為無搭接木支撐時之87.8%, 若補強方向與in-
plane面夾角45度時, 承載力提升為84.9%。由數值分析結果可知, 鋼索
預拉力與補強方向均會影響補強之效果, 理想的補強方向可使搭接木支撐
之兩層鋼管架極限承載力, 提升為兩層純鋼管架無搭接木支撐時之96%,
為實際工地中可加以考慮之補強方法。
在地基沉陷影響之鋼管架聯合支撐系統試驗方面, 當模擬沉陷之彈簧彈性
係數為432 kgf/cm與164 kgf/cm時, 無搭接木支撐之純兩層鋼管架極限承
載力, 最多可折減為無沉陷影響時之56%, 承載力之折減相當可觀。當鋼
管架上搭接85 cm之木支撐時, 模擬沉陷之彈簧彈性係數為432 kgf/cm時,
極限承載力折減為無地基沉陷影響時之35.9%, 當彈簧彈性係數為164
kgf/cm時, 更折減為19.3%。兩者之極限承載力與純兩層鋼管架之極限承
載力相比, 根本不及其15%, 幾乎無法發揮其支撐之功能, 其可觀之折減
不得不留意。由數值分析結果發現, 鋼管架底部受地基沉陷之影響時,其
極限承載力將受到地基勁度之影響而有增減, 而增減之趨勢又與地基沉陷
量相關, 另外, 木支撐與鋼管架搭接處之接頭勁度, 將因地基沉陷影響而
減弱。因此, 搭設鋼管架之工地現場, 若為鬆軟之地基時, 應先進行整平
與夯實處理, 以確保地基之強度, 避免因載重施加而有沉陷發生, 使承載
力降低。

There are two main objectives of this thesis: (1) to
determine the effects of cable strengthening on bearing capacity
of steel scaffolds with wooden shores; and (2) to investigate
how the base settlement affects the bearing capacity of the
steel scaffold system. The research work includes laboratory
experiments and numerical analyses. Experimental studies were
carried out todetermine the bearing capacity and failure modes
of the steel scaffold system.A commercial finite element code,
ANSYS, was used to perform numerical studies aimed at
establishing numerical models for parametric studies.
Experimental results show that the bearing capacity of a steel
scaffoldsystem with wooden shores is reduced dramatically to
less than 40% of thatfor a steel scaffold system without wooden
shores. As strengthened by cables,the steel scaffold system with
wooden shores can bear the load more than 80%of that for the
system without wooden shores. During the process of
stretchingcables, the forces must be symmetrically introduced
into cables to avoidstructural collapse. In addition, the base
providing cablereaction forces must be firmly fixed. Numerical
results show that the optimum initial forces in cables are 300
kgf and the cables should be placed possibly in the directionof
the weak plane of the scaffold system. It is better to have a
angle betweentwo lines formed by the cable and the ground less
than 60%.
To study the effects of base settlement, spring with various
stiffnesscoefficients was installed at the bottom of a tube of
the scaffold system.Experimental results show that the bearing
capacity of the scaffold systemwithout wooden shores subjected
to base settlement is less than 56% of thatwithout settlement.
For the scaffold system with wooden shores, the basesettlement
can dramatically reduce its bearing capacity to a degree of
losingits supporting function. Numerical studies show that the
tendency to reduce the bearing capacity will increase as the
stiffness of the base decreases.In addition, the base settlement
results in a less flexural stiffness at theinterface between the
wooden shores and the steel scaffolds. Therefore, it isstrongly
recommended that the base of a steel scaffold system be firm
enough to ensure the bearing capacity of the system as expected.
URI: http://hdl.handle.net/11455/13462
Appears in Collections:土木工程學系所

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