摘要
【目的】为建立桩板结构路基确定性安全设计和可靠度设计间的联系。【方法】首先推导了桩板结构路基沉降计算解析解,建立了桩板结构路基可靠度分析模型,研究了地基土弹性模量变异系数、上部荷载和桩间距对路基沉降失效概率的影响。然后提出了基于广义可靠度指标相对安全率的桩板结构路基沉降安全判据框架,分析了广义可靠度指标相对安全率和安全系数相对安全率的关系,进而探讨了上覆荷载对临界桩间距的影响。【结果】结果表明,该沉降计算方法能较好反映桩板结构路基沉降变形特征;桩板结构路基沉降由上部荷载和桩板组合刚度共同决定,其失效概率与荷载水平的关系曲线随地基土弹性模量变异系数的增大由陡增型转变为线性增长;广义可靠度指标相对安全率和安全系数相对安全率近似呈线性关系;此外,上覆荷载的增加将导致临界桩间距呈对数非线性减少。【结论】通过允许失效概率标定结构允许安全系数,保证了桩板结构路基确定性设计和可靠度设计的设计可行域基本一致。
【Objective】To establish the relationship between the deterministic safety design and reliability design of pile plate structure subgrade.【Method】This paper first derives the analytical solution for settlement calcula-tion of pile plate structure subgrade and establishes the reliability analysis model for the subgrade.The influence of the variability coefficient of subgrade soil elastic modulus,upper load,and pile spacing on the failure probabil-ity of subgrade settlement is studied.Subsequently,a framework for settlement safety criteria of pile plate struc-ture subgrade based on the generalized reliability ration of safety margin is proposed.The relationship between the relative safety margin of the generalized reliability index and the safety factor's relative safety margin is ana-lyzed,and the effect of overlying load on the critical pile spacing is discussed.【Result】The results show that the settlement calculation method in this paper can better reflect the settlement deformation characteristics of the pile plate structure subgrade.The settlement of the pile plate structure subgrade is jointly determined by the up-per load and the combined stiffness of the plate,and its failure probability curve with the load level changes from a steep increase to linear growth as the variability coefficient of the subgrade soil elastic modulus increases.The rela-tive safety margin of the generalized reliability index and the safety factor's relative safety margin exhibit an approxi-mately linear relationship.In addition,an increase in overlying load will lead to a logarithmic non-linear decrease in the critical pile spacing.【Conclusion】By allowing the failure probability to calibrate the allowable safety factor,the basic consistency of deterministic design and reliability design of the pile plate structure subgrade is ensured.
作者
李宝地
李锦良
冯超
Li Baodi;Li Jingliang;Feng Chao(Shaanxi Road and Bridge Group Co.,Ltd.,Xi'an 710065,China;School of Highway and Railway Engineering,Shaanxi College of Communications Technology,Xi'an 710018,China)
出处
《华东交通大学学报》
2024年第3期1-9,共9页
Journal of East China Jiaotong University
基金
陕西省交通运输厅交通科研项目(22-46K)。
关键词
道路工程
桩板结构
路基沉降
解析解
可靠度
相对安全率
roadway engineering
pile plate structure
subgrade settlement
analytical calculation
reliability
ra-tio of safety margin
