长江科学院院报2024，Vol.41Issue(7)：139-147,9.DOI:10.11988/ckyyb.20230348
高原山区微型群桩基础承载特征及竖向-水平联合荷载研究
Load Bearing Characteristics of Micropile Group Foundation in Plateau Mountainous Area under Combined Vertical-Horizontal Loads
摘要
Abstract
The aim of this study is to investigate the bearing characteristics of micropile group foundations in plateau mountainous areas under coupled horizontal and vertical loads(combined V-H loads),and to uncover the law of interaction between these loads.On the basis of field tests,FLAC3D was employed to numerically analyze three sin-gle load cases(pure vertical compression,vertical uplift,and horizontal load),and to simulate combined V-H loads on micropile group foundations with various load ratios.Results reveal distinct behaviors:1)Compression and horizontal loading tests exhibit gradual variations,underscored by significant pile cap effects,whereas pullout tests demonstrate abrupt changes.2)Under combined V-H loads,horizontal loading reduces vertical bearing capacity.Higher horizontal load proportion yields larger pile resistance moment and ultimate friction resistance along pile side,eliminating abrupt changes in the curve of load versus uplift displacement.A critical ratio(n)of vertical load to horizontal load exists,equaling 3.9 under combined compression and horizontal loads and 0.76 under combined uplift and horizontal loads.Beyond these ratios,horizontal bearing capacity weakens or strengthens accordingly.3)Under combined V-H loads,horizontal bearing capacity varies as a quartic function of load ratio inverse,while ver-tical bearing capacity varies quadratically.The yield envelope and the unidirectional ultimate load perpendicular line enclose a space divided into"failure"and"safety"zones,distinct from unidirectional load conditions.Optimal solutions exist under load coupling,maximizing the bearing capacity of foundation in all directions.关键词
微型群桩基础/V-H联合荷载/桩基承载性能/原型试验/数值模拟/高原山区/输变电工程Key words
micropile group foundation/joint vertical-horizontal loading/bearing capacity of pile foundation/pro-totype test/numerical simulation/plateau mountainous area/power transmission project分类
建筑与水利引用本文复制引用
李海涛,任光明,冯川,唐杨,王霆,王亮..高原山区微型群桩基础承载特征及竖向-水平联合荷载研究[J].长江科学院院报,2024,41(7):139-147,9.基金项目
国家电网公司科技项目(SGSCAB00JSJS1900683,SGSCDZ00JSJS2100272) （SGSCAB00JSJS1900683,SGSCDZ00JSJS2100272）
