改进规范地基承载力确定方法的建议  

Suggestions for improving the standard method for determing the foundation bearing capacity

作　　者：杨光华[1,2] YANG Guanghua(Guangdong Research Institute of Water Resources and Hydropower,Guangzhou 510610,Guangdong,China;The Geotechnical Engineering Technology Center of Guangdong Province,Guangzhou 510610,Guangdong,China)

机构地区：[1]广东省水利水电科学研究院,广东广州510610 [2]广东省岩土工程技术研究中心,广东广州510610

出　　处：《地基处理》2024年第6期633-636,共4页Journal of Ground Improvement

基　　金：国家自然科学基金(52078143)。

摘　　要：我国现行《建筑地基基础设计规范》(GB 50007—2011)和《建筑地基基础检测规范》(DBJ/T 15—60—2019)中,对压板载荷试验确定地基承载力特征值时采用沉降与压板宽度之比这一沉降比来确定,用沉降比确定的地基承载力特征值并不能保证实际基础在小于这一特征值作用下的沉降安全。另一方面按沉降比确定地基承载力特征值也可能偏小而保守,限制了对地基承载力的利用。文中提出改进规范确定地基承载力特征值的方法,认为可以把地基承载力分为强度承载力特征值和变形承载力特征值,强度承载力特征值保证地基的稳定安全,可以取载荷试验的极限荷载或最大试验荷载的50%,变形承载力特征值则依据地基基础的沉降控制要求确定,实际的允许地基承载力或修正承载力特征值则取两者的小值,这样既保证了地基的强度和变形安全,也能优化地基承载力的利用,使工程设计更科学、合理。The current Code for Design of Building Foundation(GB 50007—2011)and Code for Testing of Building Foundation(DBJ/T 15—60—2019)in China use the settlement ratio,defined as the ratio of settlement to the width of the pressure plate,to determine the characteristic value of foundation bearing capacity during the pressure plate load test.The characteristic value of foundation bearing capacity determined by the settlement ratio cannot guarantee the safety of actual foundation settlement under the action of loads smaller than this characteristic value.On the other hand,determining the characteristic value of foundation bearing capacity based on settlement ratio may be overly conservative,potentially underestimating the foundation’s bearing capacity and limiting its utilization.The article proposes a method to improve the standardized approach for determining the characteristic value of foundation bearing capacity.It suggests that foundation bearing capacity should be divided into two components:the strength bearing capacity characteristic value and the deformation bearing capacity characteristic value.The strength bearing capacity characteristic value ensures the structural stability and safety of the foundation,and can be taken as 50%of the ultimate load or the maximum test load obtained from the load test.The deformation bearing capacity characteristic value is determined based on the settlement control requirements of the foundation.The final allowable bearing capacity or modified bearing capacity characteristic value of the foundation is taken as the smaller of the two,which not only ensures the strength and deformation safety of the foundation,but also optimizes the utilization of the foundation’s bearing capacity,making engi-neering design more scientific and reasonable.

关 键 词：地基承载力特征值 变形控制 压板载荷试验 地基设计规范 

分 类 号：TU470[建筑科学—结构工程]