结合混凝土、螺栓和钢管的弹塑性变形特性,基于纵向等效连续模型和平截面假定,建立衬砌管片、输水钢管及在衬砌管片与输水钢管之间填充混凝土的受弯分析模型.求解该模型,得到地基沉降作用下盾构隧道纵向接缝张开量、最大混凝土压应变及...结合混凝土、螺栓和钢管的弹塑性变形特性,基于纵向等效连续模型和平截面假定,建立衬砌管片、输水钢管及在衬砌管片与输水钢管之间填充混凝土的受弯分析模型.求解该模型,得到地基沉降作用下盾构隧道纵向接缝张开量、最大混凝土压应变及最大钢管拉应变等关键参数.将所建模型应用于杭州某输水盾构隧道工程,结果表明:地基沉降引起隧道受弯,隧道结构将产生7类临界状态,且先后顺序为螺栓达到屈服应力、环缝张开2 mm (螺栓和管片混凝土被侵蚀)、钢管达到屈服应力、环缝张开6 mm(钢管和填充混凝土被侵蚀)、管片混凝土开始受压屈服、填充混凝土开始受压屈服、螺栓达到破坏应力.当钢管紧贴衬砌管壁时,隧道结构处于最不利工况,容易导致钢管腐蚀和隧道脆性破坏.展开更多
The flexural behavior of eight FRP （ fiber reinforced polymer） strengthened RC （reinforced concrete） beams with different steel corrosion rates are numerically studied by Ansys finite element software. The influen...The flexural behavior of eight FRP （ fiber reinforced polymer） strengthened RC （reinforced concrete） beams with different steel corrosion rates are numerically studied by Ansys finite element software. The influences of the corrosion rate on crack pattern, failure mechanism, ultimate strength, ductility and deformation capacity are also analyzed. Modeling results show that the beams with low corrosion rates fail by the crushing of the concrete in the compression zone. For the beams with medium corrosion rates, the bond slip between the concrete and the longitudinal reinforcement occurs after steel yielding, and the beams finally fail by the debonding of the FRP plates. For the beams with high corrosion rates, the bond slip occurs before steel yielding, and the beams finally fail by the crushing of the concrete in the compression zone. The higher the corrosion rates of the longitudinal reinforcement, the more the carrying capacity of FRP strengthened RC beams reduces. The carrying capacity of RCB-1 （the corrosion rate is 0） is 115 kN, and the carrying capacity of RCB-7 （the corrosion rate is 20% ） is 42 kN. The deformation capacity of FRP strengthened corroded RC beams is higher than that of FRP strengthened uucorroded RC beams. The ultimate deflection of RCB-1 and RCB-7 are 20 mm and 35 nun, respectively, and the ultimate deflection of RCB-5 （the corrosion rate is 10% ） reaches 60 ilUn.展开更多
文摘结合混凝土、螺栓和钢管的弹塑性变形特性,基于纵向等效连续模型和平截面假定,建立衬砌管片、输水钢管及在衬砌管片与输水钢管之间填充混凝土的受弯分析模型.求解该模型,得到地基沉降作用下盾构隧道纵向接缝张开量、最大混凝土压应变及最大钢管拉应变等关键参数.将所建模型应用于杭州某输水盾构隧道工程,结果表明:地基沉降引起隧道受弯,隧道结构将产生7类临界状态,且先后顺序为螺栓达到屈服应力、环缝张开2 mm (螺栓和管片混凝土被侵蚀)、钢管达到屈服应力、环缝张开6 mm(钢管和填充混凝土被侵蚀)、管片混凝土开始受压屈服、填充混凝土开始受压屈服、螺栓达到破坏应力.当钢管紧贴衬砌管壁时,隧道结构处于最不利工况,容易导致钢管腐蚀和隧道脆性破坏.
基金The National Natural Science Foundation of China(No.51278118)Scientific and Technological Research Project of Ministry of Education(No.113028A)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK2012756)the Program for Special Talents in Six Fields of Jiangsu Province(No.2011-JZ-010)
文摘The flexural behavior of eight FRP （ fiber reinforced polymer） strengthened RC （reinforced concrete） beams with different steel corrosion rates are numerically studied by Ansys finite element software. The influences of the corrosion rate on crack pattern, failure mechanism, ultimate strength, ductility and deformation capacity are also analyzed. Modeling results show that the beams with low corrosion rates fail by the crushing of the concrete in the compression zone. For the beams with medium corrosion rates, the bond slip between the concrete and the longitudinal reinforcement occurs after steel yielding, and the beams finally fail by the debonding of the FRP plates. For the beams with high corrosion rates, the bond slip occurs before steel yielding, and the beams finally fail by the crushing of the concrete in the compression zone. The higher the corrosion rates of the longitudinal reinforcement, the more the carrying capacity of FRP strengthened RC beams reduces. The carrying capacity of RCB-1 （the corrosion rate is 0） is 115 kN, and the carrying capacity of RCB-7 （the corrosion rate is 20% ） is 42 kN. The deformation capacity of FRP strengthened corroded RC beams is higher than that of FRP strengthened uucorroded RC beams. The ultimate deflection of RCB-1 and RCB-7 are 20 mm and 35 nun, respectively, and the ultimate deflection of RCB-5 （the corrosion rate is 10% ） reaches 60 ilUn.
