徐志军，赵世鹏，王政权，等.基于GBDT算法的基桩竖向承载力预测方法［J］.河南理工大学学报（自然科学版），2024，43（2）：186-193.

XU Z J，ZHAO S P，WANG Z Q，et al.Prediction method of vertical bearing capacity of piles assisted with GBDT algorithm［J］.Journal of Henan Polytechnic University（Natural Science），2024，43（2）：186-193.

基于GBDT算法的基桩竖向承载力预测方法

徐志军，赵世鹏，王政权，田江涛，宗飞龙

河南工业大学 土木工程学院，河南 郑州 450000

摘要: 目的 为研究支撑-半刚接钢框架结构体系的抗震性能，方法 设计了一榀由嵌套式单边螺栓与T型钢构成的半刚性梁柱节点的中心支撑钢框架，并进行了拟静力试验与有限元数值模拟，通过观测整个试验现象，分析了其滞回、承载力、刚度退化、耗能等抗震指标。结果 结果表明：试件破坏过程明显经历了弹性段、塑性段、破坏段三个阶段，试件破坏模式主要为支撑受压失稳破坏，塑性变形主要累积在支撑体系上，整体呈现延性破坏特征；支撑断裂后，梁柱及T型钢节点无明显塑性变形，钢框架仍具有较高的安全储备，符合“强节点、弱构件”设计原则，表明了结构具有两道抗震防线；结论 支撑与半刚接钢框架协同工作使得试件具有较高的抗侧刚度抵抗水平变形，且承载力较高、滞回性能稳定、耗能能力优良；单边螺栓在试验过程中的受力性能较普通高强螺栓并无较大差别，未出现严重的预紧力松弛现象，并能高效的保持螺栓预紧力。通过有限元数值模拟分析可知，减小支撑长细比，虽能有效提高结构的抗震性能，但长细比较小会导致支撑刚度增大，加速其余构件的损坏。故应以考虑结构的延性为前提，降低支撑的长细比，才能有效提高结构的抗震性能。

关键词:基桩竖向承载力；梯度提升决策树；预测模型；评价指标；鲁棒性

doi:10.16186/j.cnki.1673-9787.2022110051

基金项目:国家自然科学基金资助项目（51978247）

收稿日期: 2022/11/21

修回日期: 2023/03/13

出版日期:2024/03/25

Prediction method of vertical bearing capacity of piles assisted with GBDT algorithm

XU Zhijun，ZHAO Shipeng，WANG Zhengquan，TIAN Jiangtao，ZONG Feilong

College of Civil Engineering，Henan University of Technology，Zhengzhou 450000，Henan，China

Abstract: Objectives In order to study the seismic performance of braced and semi-rigid steel frame structure system， Methods a center-braced steel frame with semi-rigid beam-column joints composed of nested one-side bolts and T-stub was designed. Quasi-static test and finite element numerical simulation were conducted to analyze seismic indicators such as hysteresis， bearing capacity， stiffness degradation， and energy dissipation by observing the entire experimental phenomenon. Results The results show that the failure process of the specimen has gone through three stages： elastic section， plastic section， and failure section. The failure mode of the specimen is mainly the buckling failure of the brace under compression，and the plastic deformation mainly accumulates on the brace system， presenting the characteristics of ductile failure as a whole.After the brace breaks，there is no obvious plastic deformation in the beam-column and T-shaped steel joints，and the steel frame still has a high safety reserve，which conforms to the design principle of “strong joints and weak members.” It indicates that the structure has two lines of seismic resistance. Conclusions The cooperative work of brace and semi-rigid steel frame makes the specimen have high lateral stiffness，horizontal deformation resistance， high bearing capacity， stable hysteretic performance， and excellent energy dissipation capacity.During the test， the mechanical performance of the one-side bolts is not significantly different from that of the ordinary high-strength bolt，and there is no serious relaxation of the preload；it can effectively maintain the bolt preload. Through finite element numerical analysis，it is known that reducing the slenderness ratio of brace can effectively improve the seismic performance of the structure.However，a small slenderness ratio can lead to an increase in the stiffness of the brace and accelerate the damage of other components. Therefore， in order to effectively improve the seismic performance of the structure，it is necessary to consider the ductility of the structure and reduce the slenderness ratio of the brace.

Key words:vertical bearing capacity of piles；gradient boosting decision tree；prediction model；evaluation index；robustness