受軸力影響之鋼板混凝土複合牆耐震行為分析研究

An Analytical Study on Seismic Behavior of Steel-Plate Composite Walls Subjected to Axial Compression

高翊書(Yi-Shu Kao)

指導教授 ： 黃尹男

國立臺灣大學/工學院/土木工程學研究所/碩士(2019年)

https://doi.org/10.6342/NTU201902904

摘要

鋼板混凝土複合牆(Steel-Plate Composite Wall，簡稱SC牆)係以兩片鋼板內填充混凝土材料組合而成，具有高勁度與高強度。最早是應用於核能設備結構，因為高強度、施工快速，近幾年開始被應用於超高樓核心筒。用於超高樓核心筒之SC牆會受到軸力之影響，而現今設計規範AISC_341-16 (2016)的公式是假設牆體受純剪下之行為，公式中並未考慮牆體軸力對剪力強度之影響。在實務應用上，SC牆用於結構中抵抗側向載重時並非受到純剪作用，其行為應考慮到撓曲與剪力互制之影響；另一方面，SC牆兩端具有與其垂直相接的另一向牆體，猶如牆體之邊界構材，能使SC牆的撓曲強度大幅提升，進而可能使牆體破壞模式轉變為以剪力破壞所主控。因此，受軸力下含邊界構材之SC牆平面內剪力強度與撓曲強度之預測為一重要議題。
目前含邊界構材之SC牆平面內強度的相關研究中，關於軸力對剪力強度之影響看法不一，本研究將針對此議題進行研究。為研究軸力之影響，引入「軸壓比」一參數，並考量不同高度之牆體受軸力之影響程度會有差異，因此同時考慮「高寬比」一參數，最終發展出一套具有物理意義之剪力強度預測模型，能夠解釋並掌握軸力對剪力強度之影響。
本研究依上述兩參數之合理範圍，設計出參數分析所用之一組案例SC牆(簡稱分析試體)，進行斷面分析與有限元素分析。透過斷面分析了解軸力對撓曲強度與壓力區深度之影響；有限元素分析模型透過以往試驗結果驗證其準確性，並用此模型觀察出SC牆中鋼板與混凝土的側力位移曲線趨勢。接著，藉由SC牆之側力位移趨勢建立一剪力強度預測模型，並利用有限元素模型建立分析試體之耐震行為資料庫，將預測模型與資料庫比較，驗證預測模型能夠有效掌握軸力的影響，準確預估受軸力下的剪力強度，且符合SC牆的物理意義。為進一步簡化預測模型，如同規範公式的做法，採用迴歸分析的方式進行簡化，迴歸過程除了考量軸力，也對規範之參數進行適當的修正，最終，發展出一套簡化後的剪力強度預測模型。

關鍵字

鋼板混凝土複合牆 ； 剪力強度 ； 軸力 ； 軸壓比 ； 高寬比 ； 有限元素分析 ； 擬靜態反覆試驗

並列摘要

Steel-Plate Composite Wall (SC-wall) is a combination of two sheets of steel filled with concrete with high stiffness and high strength. It was first applied to the structure of nuclear power equipment. Because of its high strength and rapid construction, it has been applied to the core of super-high buildings in recent years. The SC wall used in the core tube of the super-high building will be affected by axial force. The shear strength formula of the current design specification AISC_341-16 (2016) assumes that the wall is subjected to pure shearing behavior, and axial force of the wall is not considered in the formula. In practice, the SC wall is not subjected to pure shearing when it is used to resist lateral load in the structure. Its behavior should take into account the influence of flexural and shear interaction. On the other hand, there are boundary walls at both ends of the SC wall. The boundary walls, like the boundary element of the SC wall, can greatly increase the flexural strength of the SC wall, which may change the wall failure mode to be dominated by shear damage. Therefore, the prediction of the in-plane shear strength and flexural strength of the SC wall with boundary members under axial force is an important issue.
In the current research on the in-plane strength of SC wall with boundary members, the effect of axial force is inconclusive. Therefore, this study will focus on this topic. In order to study the influence of axial force, this parameter of "axial compression ratio" was introduced. When the wall height is different, the influence of the axial force is different, so consider the "aspect ratio" parameter.
In order to research the influence of axial force, a parameter of "axial pressure ratio" is introduced, and the degree of influence of the axial force of the wall of different heights is considered. Therefore, considering the "aspect ratio" parameter, a set of The physical significance of the shear strength prediction model can explain and grasp the influence of axial force on shear strength. Finally, a set of physical prediction model of shear strength is developed to explain the effect of axial force on shear strength.
Based on the reasonable range of the above two parameters, this study designed a set of case SC wall (referred to as analytical sample) used for parameter analysis, and carried out section analysis and finite element analysis. Through the section analysis, the influence of axial force on the flexural strength and the depth of the pressure zone is known. The finite element model verifies its accuracy through previous experiment results. Use this model to observe the trend behavior of steel plate and concrete in SC wall. Then, a shear strength prediction model is established, and the finite element models are used to establish a database. The shear strength under axial force is accurately predicted by the prediction model which conforms to the physical meaning of the SC wall. In order to simplify the prediction model, as in the case of the design specification, regression analysis is used to simplify. In addition to considering axial force, the regression process also corrects the parameters of the specification. Finally, a simplified model of shear strength prediction is developed.

並列關鍵字

Steel-plate composite wall ； Shear strength ； Axial force ； Axial pressure ratio ； Aspect ratio ； Finite element method analysis ； In-plane cyclic loading

參考文獻

ACI (318-08). Design of reinforced concrete : ACI 318-08, John Wiley & Sons, Hoboken.

ACI_318-14 (2014). Building code requirements for structural concrete (ACI 318-14) : an ACI standard : commentary on building code requirements for structural concrete (ACI 318R-14), an ACI report.

AISC_341-16 (2016). "AISC 341-16 (2016). “Seismic Provisions for Structural Steel Buildings.” ANSI/AISC 341-16, American Institute of Steel Construction, Chicago, Illinois.".

AISC_N690s1-15 (2015). AISC N690s1-15 (2015). “Specification for Safety-Related Steel Structures for Nuclear Facilities.” AISC N690s1-15, American Institute of Steel Construction, Chicago, Illinois.

Booth, P., and Varma, A. (2015). Lateral Load Capacity of Steel Plate Composite Wall Structures.