南京工业大学学报（自然科学版）2025，Vol.47Issue(3)：297-307,11.DOI:10.3969/j.issn.1671-7627.2025.03.009
阶梯形承台岩锚基础承载力及其发挥机制
Bearing capacity and mobilization mechanism of rock anchor foundation with stepped cap
摘要
Abstract
To tackle the challenges in application of rock anchor foundation due to large cap dimension and extensive rock excavation in mountain areas,a new type of rock anchor foundation with a stepped cap is proposed,with a bottom profile designed to adapt to the terra in slope.To study the bearing behavior of the proposed stepped cap rock anchor foundation and promote its application in power transmission tower foundations,field tests were conducted at a typical rocky site in the mountainous area of Zhejiang Province.First,four full-size foundations with different bottom slope angles,embedment depths,and step numbers were designed based on the uplift and horizontal loads applied on 220 kV power transmission towers in China.Corresponding loading systems were also developed to reliably apply uplift and horizontal forces on the foundation.Through combined uplift and horizontal load field tests,the load-displacement curves,uplift bearing capacity,and the mobilization patterns of anchor resistance were obtained.Subsequently,refined numerical simulations were conducted to reveal the mobilization mechanism of the foundation's bearing capacity.The results showed that the uplift bearing capacity of the stepped-cap foundation was mobilized through a process where the bonding at the cap-rock interface gradually diminished,and the rock anchors progressively engaged in load-bearing.The vertical facets of the stepped cap at the bottom of the foundation were subject to additional constraints from the surrounding rock mass due to cap rotation,which enhanced the bearing capacity of the foundation.This constraint effect intensified with an increasing number of steps.The deformation patterns of the anchors varied across the three steps.The anchor at the top step primarily underwent oblique pull-out deformation,the anchor at the middle step mainly experienced vertical uplift deformation,and the anchor at the bottom step was mainly subject to bending deformation.The geometric parameters of the foundation(bottom slope angle,embedment depth,and step number)influenced the relative deformation between the cap and rock mass,thereby affecting the mobilization of anchor resistance.However,they had minimal influence on the ultimate uplift bearing capacity.Theoretical calculations over estimated the axial force in the anchor of the stepped cap,representing a conservative calculation method.关键词
岩锚基础/阶梯形承台/现场抗拔试验/承载力/发挥机制Key words
rock anchor foundation/stepped-cap foundation/field uplift test/bearing capacity/mobilization mechanism分类
建筑与水利引用本文复制引用
楼佳悦,章李刚,申志福,任远,李燚,李坚卿..阶梯形承台岩锚基础承载力及其发挥机制[J].南京工业大学学报（自然科学版）,2025,47(3):297-307,11.基金项目
国家自然科学基金(51908284) （51908284）
浙江华云电力工程设计咨询有限公司科技项目(2022C1D04P11) （2022C1D04P11）
