板间距对风积沙金属装配式基础上拔承载力影响研究  

Influence of slab spacing on uplift bearing capacity of metal grillage foundations in aeolian sand

作　　者：张程程 刘观仕[2] 杨景胜 赵青松 徐国方 ZHANG Chengcheng;LIU Guanshi;YANG Jingsheng;ZHAO Qingsong;XU Guofang(Guangxi Key Laboratory of Rock and Soil Mechanics and Engineering,Guilin University of Technology,Guilin,Guangxi 541004,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China;Zhongnan Electric Power Design Institute Co.,Ltd.,China Power Engineering Consulting Group,Wuhan,Hubei 430071,China)

机构地区：[1]桂林理工大学广西岩土力学与工程重点实验室,广西桂林541004 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [3]中国电力工程顾问集团中南电力设计院有限公司,湖北武汉430071

出　　处：《岩石力学与工程学报》2022年第10期2149-2160,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(52179115);中国电力工程顾问集团公司中南电力设计院有限公司委托科研项目(DG1-T03-2018)。

摘　　要：新能源电力工程建设的发展,正推动金属装配式基础在风积沙地区的应用,底板间距的设计关系到上拔承载力的计算与成本控制。为此,在风积沙地基中开展真型试验与活动门试验,研究板间距与板宽之比为1.0,1.5和2.0情况下,基础的承载力、应力、周边土压力变化规律及板间土拱发展规律。结果表明,金属装配式基础的上拔承载力随板间距增大而线性减小;支架应力随板间距增大而减小,随距底板高度增大而增大,底板应力变化与支架相反,最大应力多出现于板条悬挑处;板间距对基础破裂面位置几乎无影响,反算的上拔角为20°;活动门试验发现,板间距越大,土拱越高,板间损失土体的体积越大,导致基础抗力损失越多;考虑板间土拱效应对土重法进行修正,计算结果更接近上拔承载力实测值。研究成果可为金属装配式基础板间距的合理设计提供参考依据。New energy power engineering construction is promoting the application of metal grillage foundations in aeolian sand areas.The design of the slab spacing involves the calculation of uplift bearing capacity and cost control.Therefore,full-scale uplift tests and trapdoor experiments for grillage foundations were carried out in aeolian sand.The variation in bearing capacity,stress and surrounding soil pressure of foundations as well as the development of the soil arch between the slabs,were investigated in the cases of the ratios of the slab spacing to the slab width of 1.0,1.5 and 2.0.The results show that:(1)the uplift bearing capacity of metal grillage foundations decreases linearly with the slab spacing;(2)the stress in the support decreases with the slab spacing,while increases with the height from the bottom slab.The change of the stress in the bottom slabs is opposite to that in the support,and the maximum stress mostly appears in the cantilever parts of the slabs;(3)the slab spacing has little effect on the location of the sliding plane,and the back-calculated angle of the slip plane to the horizontal is 20°;(4)the results of trapdoor experiment indicate that the larger the slab spacing is,the higher the soil arch is and the larger the lost volume of soil between the slabs is resulting in increasing loss of the foundation resistance;(5)considering the soil arching effect between the slabs,the soil weight method is modified,and the calculated results are closer to the tested uplift bearing capacity.The research can provide references for optimal slab spacing in grillage foundation design.

关 键 词：土力学 风积沙 金属装配式基础 板间距 土拱效应 上拔承载力 

分 类 号：TU41[建筑科学—岩土工程]