岩土力学
巖土力學
암토역학
Rock and Soil Mechanics
2015年
11期
3077-3084,3093
,共9页
张俊儒%孙克国%卢锋%郑宗溪%孙其清
張俊儒%孫剋國%盧鋒%鄭宗溪%孫其清
장준유%손극국%로봉%정종계%손기청
不等跨连拱隧道%围岩压力%受力特征%模型试验
不等跨連拱隧道%圍巖壓力%受力特徵%模型試驗
불등과련공수도%위암압력%수력특정%모형시험
unequal-span double-arch tunnel%surrounding rock pressure%mechanical characteristics%model test
以兰渝铁路新作坊隧道洞口明挖段不等跨连拱结构为背景,采用室内模型试验的方法,对不等跨连拱铁路隧道围岩压力分布及受力特征进行研究。试验结果表明:隧道水平侧压力均小于竖向围岩压力,拱顶处侧压力小于墙脚处侧压力,小洞侧侧压力系数平均为0.55,大洞侧侧压力系数平均为0.65;中隔墙顶部围岩压力均大于拱顶处围岩压力,且大洞拱顶围岩压力约为小洞的1.2倍;隧道结构总体为小偏心压弯构件,大洞所承受的轴力总体比小洞承受的轴力大20%~30%;隧道先后在大小洞靠近中隔墙的拱腰及仰拱处破坏,最终发生整体失稳;靠近中隔墙的大小洞拱腰及仰拱是设计施工时应重点关注的部位;最终获得不等跨连拱铁路隧道的围岩压力分布模式,研究结果可以直接指导新作坊隧道结构的设计与施工,有利于完善不等跨连拱隧道设计施工理念。
以蘭渝鐵路新作坊隧道洞口明挖段不等跨連拱結構為揹景,採用室內模型試驗的方法,對不等跨連拱鐵路隧道圍巖壓力分佈及受力特徵進行研究。試驗結果錶明:隧道水平側壓力均小于豎嚮圍巖壓力,拱頂處側壓力小于牆腳處側壓力,小洞側側壓力繫數平均為0.55,大洞側側壓力繫數平均為0.65;中隔牆頂部圍巖壓力均大于拱頂處圍巖壓力,且大洞拱頂圍巖壓力約為小洞的1.2倍;隧道結構總體為小偏心壓彎構件,大洞所承受的軸力總體比小洞承受的軸力大20%~30%;隧道先後在大小洞靠近中隔牆的拱腰及仰拱處破壞,最終髮生整體失穩;靠近中隔牆的大小洞拱腰及仰拱是設計施工時應重點關註的部位;最終穫得不等跨連拱鐵路隧道的圍巖壓力分佈模式,研究結果可以直接指導新作坊隧道結構的設計與施工,有利于完善不等跨連拱隧道設計施工理唸。
이란투철로신작방수도동구명알단불등과련공결구위배경,채용실내모형시험적방법,대불등과련공철로수도위암압력분포급수력특정진행연구。시험결과표명:수도수평측압력균소우수향위암압력,공정처측압력소우장각처측압력,소동측측압력계수평균위0.55,대동측측압력계수평균위0.65;중격장정부위암압력균대우공정처위암압력,차대동공정위암압력약위소동적1.2배;수도결구총체위소편심압만구건,대동소승수적축력총체비소동승수적축력대20%~30%;수도선후재대소동고근중격장적공요급앙공처파배,최종발생정체실은;고근중격장적대소동공요급앙공시설계시공시응중점관주적부위;최종획득불등과련공철로수도적위암압력분포모식,연구결과가이직접지도신작방수도결구적설계여시공,유리우완선불등과련공수도설계시공이념。
A model test is carried out to study the distribution of surrounding rock pressure and its mechanical characteristics based on open excavation section of Xinzuofang unequal-span double-arch tunnel of Lanzhou-Chongqing railway. Test results show that lateral pressure acting on the tunnel is smaller than the vertical stress of surrounding rock, and lateral pressure at the crown is smaller than that at the bottom of side wall, moreover, lateral pressure coefficient of small hole side is about 0.55 on average, while the big hole side is about 0.65. The stress of surrounding rock on the top of middle wall is bigger than that on the crown;the surrounding rock stress of big hole side is about 1.2 times that of the small hole. The tunnel is in a small eccentric bending state, and thrust stress in big hole is about 20%to 30%greater than that in small hole side;the destroy of tunnel structure firstly occurs at hance and invert near the middle wall in succession, finally the whole structure collapse; thus, the hance and invert near the middle wall are the place that should be focused on in the design and construction. Based on the above, the mode of surrounding rock pressure distribution is obtained finally. The results can directly provide guidance for the design and construction of Xinzuofang tunnel;what’s more, it’s also helpful to improving the design and construction concepts related to the unequal-span double-arch tunnel.