基于正交试验的坑中坑加固效果影响因素分析

Analysis of factors influencing the effect of pit-in-pit reinforcement based on orthogonal test

文章利用MIDAS/GTS有限元软件模拟坑中坑模型,研究坑中坑最佳加固区域,提出最合适加固尺寸,并通过改变加固体在平台中的位置及加固体弹性模量2个关键因素来探究其对加固效果的影响,最后设计正交试验来确定关键因素的显著性。研究结果表明:在对坑中坑平台靠外坑围护桩一侧进行加固时效果最好,最合适加固范围为深度为7 H/6(H为外坑开挖深度),宽度为3B/5(B为坑中坑平台宽度);加固体在平台中的位置及加固体弹性模量2个因素对加固效果的影响均有一定限值,且对桩顶侧向位移影响最大;加固体距外坑距离因素的显著性最高,其次为加固体深度和加固体弹性模量,最后为加固体宽度。研究结果可为类似坑中坑工程项目设计和施工提供理论参考。

This paper uses MIDAS/GTS finite element software to establish pit-in-pit model,studies the best reinforcement area of the pit-in-pit,proposes the most suitable reinforcement size,and then explores the impact of the position of the reinforcement in the platform and the elastic modulus of the reinforcement on the reinforcement effect.Finally,the orthogonal tests are designed to discuss the significance of the key factors affecting the reinforcement effect.Research indicates that the effect is the best when the pit-in-pit platform is reinforced on the side of the outer pit retaining pile,the most suitable reinforcement depth is 7 H/6(H is the excavation depth of the outer pit)and the width is 3 B/5(B is the width of the platform).The position of the reinforcement in the platform and the elastic modulus of the reinforcement have limited effect on the reinforcement,and have the greatest impact on the lateral displacement of the pile top.The significance of the factor of the distance between the reinforcement and the outer pit retaining pile is the highest,followed by the depth and elastic modulus of the reinforcement,and finally the width of the reinforcement.The research conclusions can provide a theoretical reference for the design and construction of similar pit-in-pit engineering projects.