串联式锚定板抗拔承载特性及影响因素分析

Analysis of pullout bearing characteristics and influencing factors of tandem anchor plates

为提高锚定板抗拔承载能力,设计串联式锚定板锚固系统。借鉴侧向受荷桩的“M”法,通过锚固系统受力平衡条件及位移连续性条件,提出串联式矩形锚定板锚固系统抗拔力-位移关系的理论分析方法。基于FLAC3D有限差分软件,建立锚定板锚固系统与土相互作用的数值模拟模型,进行埋设于黏性土中不同尺寸的方形锚定板抗拔承载力室内模型试验。结合室内模型试验及数值模拟结果,通过拟合分析,获得串联式矩形锚定板锚固系统抗拔力-位移关系的近似解析解,将3个工程案例中不同尺寸及埋深的锚定板抗拔力-位移的现场试验结果与理论分析及数值模拟结果对比,验证理论分析方法及数值模拟结果的正确性。探讨串联式方形锚定板锚固系统埋深及相邻锚定板间距对锚固系统抗拔承载力的影响。研究结果表明:当锚定板锚固系统埋深H<5b(b为锚定板边长)时,其破坏模式呈现浅埋锚定板的破坏特征;当埋设深度H≥5b时,其破坏模式呈现深埋锚定板破坏特征。对于串联式锚定板锚固系统,为避免相邻锚定板相互影响而降低锚固系统的抗拔承载能力,相邻锚定板间距应满足L≥3b。

In order to improve the pullout bearing capacity of the anchor plate,a tandem anchor plates anchoring system was proposed.Based on the"M"method of the laterally loaded pile,the theoretical analysis method of the pull-out resistance−displacement relationship of the tandem rectangular anchor plates anchoring system was established by the force equilibrium condition and displacement continuity condition of the anchoring system.Based on FLAC3D finite difference software,a numerical simulation model of the interaction between anchoring system of anchor plate and soil was established,and the indoor modeling tests of the pull-out capacity of square anchor plate of different sizes buried in cohesive soil were carried out.Combining the indoor model test and numerical simulation results,the approximate analytical solution of the relationship between the pull-out resistance and displacement of the tandem rectangular anchor plates anchoring system was obtained by fitting analysis.The field test results of the pull-out resistance and displacement of the anchor plates with different sizes and depths of burial of the three engineering cases were compared with the theoretical analysis and numerical simulation results,and the correctness of the theoretical analysis method and numerical simulation results was verified.The effects of the burial depth of the tandem square anchor plates anchoring system and the spacing between neighboring anchor plates on the pull-out bearing capacity of the anchoring system were investigated.The results show that when the anchor plate anchoring system is buried at a depth of H<5b(b is the side length of the anchor plate),its damage pattern presents the damage characteristics of shallow buried anchor plate,and when the buried depth H≥5b,its damage pattern presents the damage characteristics of deep buried anchor plate.For the tandem anchor plates anchoring system,in order to avoid the mutual influence of neighboring anchor plates to reduce the pullout bearing capacity of the anchoring system,the spacing of neighboring anchor plates should meet L≥3b.