CAJ | 학술논문

坑中坑式基坑由于相关设计规范对一些关键参数的确定缺乏明确规定，有时因为对内坑开挖引起外坑支护结构土压力的变化估计不足而引发一些工程事故；现有研究成果在坑中坑工程的被动区土压力分析中，没有考虑岩土工程中广泛存在的土拱效应，土压力分析不准确。通过合理的假定，对内坑支撑刚度较大且距离外坑支护结构较近的情况下，建立了无黏性土被动土压力力学模型，分析得到了坑间土体在极限应力条件下基于土拱效应的水平土压力系数和主应力旋转角；利用水平分层分析法求解得到了考虑土拱效应的被动土压力分布、合力大小、合力作用点位置等表达式。通过算例与经典土压力理论分析成果比较表明，研究成果能更好地反映实际土压力分布。
갱중갱식기갱유우상관설계규범대일사관건삼수적학정결핍명학규정，유시인위대내갱개알인기외갱지호결구토압력적변화고계불족이인발일사공정사고；현유연구성과재갱중갱공정적피동구토압력분석중，몰유고필암토공정중엄범존재적토공효응，토압력분석불준학。통과합리적가정，대내갱지탱강도교대차거리외갱지호결구교근적정황하，건립료무점성토피동토압력역학모형，분석득도료갱간토체재겁한응력조건하기우토공효응적수평토압력계수화주응력선전각；이용수평분층분석법구해득도료고필토공효응적피동토압력분포、합력대소、합력작용점위치등표체식。통과산례여경전토압력이론분석성과비교표명，연구성과능경호지반영실제토압력분포。
Due to the lack of a clear definition for some key parameters in engineering design specifica-tions,the wrong estimation of earth pressure produced by the inner pit excavation often results in acci-dents.The existing researches of earth pressure in the passive zone of pit-in-pit have not considered the soil arching effects,which widely exist in geotechnical engineering.As a result,an accurate analysis on passive earth pressure is impossible.In this paper,an earth pressure mechanical model of cohesionless soil is established by presuming the inner pit support structure with large stiffness and very close to the outer pit support structure.Coefficient of earth pressures and the large principal stress rotation angle are obtained by analysing the horizontal earth pressure between two pit supporting structures at a limit state based on soil arching effects,and then the theoretical formulae and the force point are obtained.The case study shows that this method can better reflect the actual situation by analysing horizontal differential ele-ments comparing to the classical earth pressure theory.