摘要
隧道衬砌发生的局部破坏主要由轴向压力和弯矩控制,因此其承载能力极限状态设计重点在于结构在偏心受压作用下的验算。为了研究钢纤维混凝土(SFRC)应用于隧道衬砌时的受力特征,确定承载能力极限状态时的衬砌断面应力分布,参考国内外相关试验标准和分析方法,对32个钢纤维混凝土压弯梁进行了韧性试验,并得到了32个试件的荷载-张口位移(CMOD)曲线。通过分析试验结果,确定了特定水泥基体、钢纤维类型和掺量等情况下钢纤维混凝土应力-应变本构关系简化模型中受拉区强度指标,并提出了在考虑轴力及附加偏心时,与梁高有关的尺寸效应经验公式。
Local failure occurred in tunnel lining is mainly caused by the axial pressure and bending moment,hence the design of ultimate bearing capacity limit state is focused on checking the structure in eccentric compression.In order to study the stress characteristics of steel fiber reinforced concrete( SFRC) applied in tunnel lining,determining the stress distribution of tunnel lining under the ultimate limit state,a toughness test of 32 SFRC compression-bending beams was conducted referring to relevant experiment guidelines and analytical methods at home and abroad. Based on the test results,load-crack mouth opening displacement( CMOD) curves of 32 SFRC specimens were obtained,the strength indices in the tension zone of the simplified model of SFRC stress-strain relationship for given concrete of given cement matrix,given steel fiber type and given steel fiber mixture ratio had been determined; an empirical size-effect formula related to beam depth in consideration of both axial force and additional eccentricity was proposed.
出处
《地下空间与工程学报》
CSCD
北大核心
2014年第S2期1800-1805,1810,共7页
Chinese Journal of Underground Space and Engineering
基金
中央高校基本科研业务费专题项目(SWJTU11ZT33)
关键词
钢纤维混凝土
残余抗弯拉强度
张口位移
本构关系
隧道衬砌
尺寸效应
steel fiber reinforced concrete(SFRC)
residual flexural and tensile strength
crack mouth opening displacement(CMOD)
constitutive relation
tunnel lining
size effect
