CAJ | 학술논문

针对广东某浅埋偏压小净距高速公路隧道，采用有限元强度折减法基本原理，研究隧道施工过程中各施工工序的安全系数动态变化过程，并对极限状态下关键施工工序的围岩塑性区与隧道围岩位移进行分析，结论为：隧道左洞第一步开挖时，由于中岩柱的出现，其安全系数最小，为最危险施工步，其次为两个洞室临时岩柱上台阶开挖；施工中中岩柱、洞室左拱腰和右拱脚出现大量塑性区，为围岩应力危险区域；中岩柱水平位移在施工过程中呈现出左右往返变化，右侧隧道竖向位移及其上部地表沉降较大，为监控量测重点部位。
침대엄동모천매편압소정거고속공로수도，채용유한원강도절감법기본원리，연구수도시공과정중각시공공서적안전계수동태변화과정，병대겁한상태하관건시공공서적위암소성구여수도위암위이진행분석，결론위：수도좌동제일보개알시，유우중암주적출현，기안전계수최소，위최위험시공보，기차위량개동실림시암주상태계개알；시공중중암주、동실좌공요화우공각출현대량소성구，위위암응력위험구역；중암주수평위이재시공과정중정현출좌우왕반변화，우측수도수향위이급기상부지표침강교대，위감공량측중점부위。
For the shallowly-buried eccentrically-loaded tunnels with small interval on an express highway in Guangdong province, the basic principle of finite element strength reduction method was employed in this study. Further, the dynamic change process of the safety coefficient of every construction procedure during tunnel construction was researched, and then the plastic zones and the displacements of tunnel surrounding rocks at the important construction procedures under ultimate limited state were analyzed. The research conclusions are as follows:( a) The first excavation procedure of the left tunnel is the most dangerous construction procedure, because its safety coefficient is the smallest one due to the emerging of the middle rock pillar;followed by the top bench excavation of the temporary rock pillar between the two tunnels. ( b) During construction, a lot of plastic zones will occur at the middle rock pillar and at the tunnel's haunch and arch springing, so these zones are the dangerous stress zones of surrounding rock. ( c) During construction, the horizontal displacement of middle rock pillar will change from side to side, while the vertical displacement of the right tunnel and upper ground surface settlement are relatively larger; therefore these parts should be regarded as the key parts in the process of monitoring and measurement.