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（中南林業(yè)科技大學(xué)土木工程學(xué)院， 長沙 410004）
［摘要］通過三榀單層雙跨體外預(yù)應(yīng)力混凝土框架結(jié)構(gòu)試驗研究，對比分析了中柱失效后體外預(yù)應(yīng)力混凝土框架與非預(yù)應(yīng)力混凝土框架連續(xù)倒塌的破壞全過程。研究結(jié)果表明：體外預(yù)應(yīng)力混凝土框架的連續(xù)倒塌過程分為梁機(jī)制與懸鏈線機(jī)制兩個階段，梁機(jī)制階段的倒塌抗力由體外預(yù)應(yīng)力筋的“懸索效應(yīng)”與框架梁的正截面抗彎承載力共同提供，約為非預(yù)應(yīng)力混凝土框架的1.5～2.6倍； 懸鏈線機(jī)制階段的倒塌抗力由體外預(yù)應(yīng)力筋和普通鋼筋的“懸索效應(yīng)”共同提供，約為非預(yù)應(yīng)力框架的3.5～6.1倍。體外預(yù)應(yīng)力筋的“反拱”作用將抑制框架壓拱機(jī)制的形成。直線布筋的框架倒塌極限變形約為非預(yù)應(yīng)力框架的1.5倍； 折線布筋的框架倒塌極限變形與非預(yù)應(yīng)力框架基本一致。結(jié)合試驗結(jié)果與現(xiàn)象對試驗?zāi)Ｐ涂蚣苁芰^程進(jìn)行了分析，推導(dǎo)出了基于結(jié)構(gòu)變形的體外預(yù)應(yīng)力混凝土框架倒塌抗力計算公式，計算結(jié)果與試驗結(jié)果吻合良好，可用來預(yù)估考慮懸鏈線作用的體外預(yù)應(yīng)力混凝土框架的倒塌極限抗力。
［關(guān)鍵詞］體外預(yù)應(yīng)力混凝土框架； 連續(xù)倒塌； 靜力試驗； 懸鏈線作用； 預(yù)應(yīng)力
中圖分類號：TU398-7文獻(xiàn)標(biāo)識碼：A文章編號：1002-848X(2020)23-0077-09
Research on collapse resistance performance of external prestressed concrete frame
FAN Yunlei, WANG Jie, PENG Yifan
(College of Civil Engineering, Central South University of Forestry and Technology, Changsha 410004, China)
Abstract:Through the experimental research on the external prestressed concrete frame structure of three single-story two-span, the failure process of the progressive collapse of the external prestressed concrete frame and the non-prestressed concrete frame after the failure of the middle-column was compared and analyzed. The research results show that the progressive collapse of external prestressed concrete frame is divided into two stages: the beam mechanism stage and the catenary mechanism stage. The collapse resistance with beam mechanism is jointly provided by the “catenary effect” of external prestressing tendons and ultimate moment capacity in normal section of frame beam, which is about 1.5～2.6 times that of the non-prestressed concrete frame. The collapse resistance with catenary mechanism is provided by the "catenary effect" of external prestressing tendons and non-prestressed tendons, which is about 3.5～6.1 times that of non-prestressed frame. The "anti-arch" effect of external prestressing tendons will restrain the formation of compressive arch action. The collapse limit deformation of the frame with linearly arranged tendons is about 1.5 times that of the non-prestressed frame. The collapse limit deformation of the frame with tendons arranged in the broken line is basically the same as that of the non-prestressed frame. Based on the test results and phenomena, the force process of the experimental model frame was analyzed, and the formula of the collapse resistance of external prestressed concrete frame based on the structural deformation was deduced. The calculation results are in good agreement with the experimental results and can be used to predict the ultimate resistance of external prestressed concrete frame considering the role of the catenary action.
Keywords:external prestressed concrete frame; progressive collapse; static test; catenary action; prestressing
*國家自然科學(xué)基金青年基金項目（51308556）。
作者簡介：范云蕾，博士，副教授，碩士生導(dǎo)師，Email:fanyunlei@163.com。
