深基坑内撑式支护结构的有限差分算法研究  

Research of finite difference method on retaining structures with internal braces in deep excavation engineering

作　　者：陈林靖[1] 孙永佳[1,2] 王志刚[1] 

机构地区：[1]福州大学岩土工程研究所,福建福州350108 [2]天津市天友建筑设计股份有限公司,天津300384

出　　处：《岩石力学与工程学报》2016年第A01期3315-3322,共8页Chinese Journal of Rock Mechanics and Engineering

摘　　要：为克服现行规范建议采用单参数m法的缺点,将分析水平推力桩的综合刚度原理和双参数法延伸至作用有水平分布荷载的基坑内撑式支护结构变形和内力计算中,建立一种基于此原理和方法的改进的弹性地基梁有限差分算法。此外,为考虑动态施工过程,引入增量法对各工况进行计算分析,并根据现场实测数据,反演出合适的综合刚度和双参数。计算结果表明,该方法得到的水平位移和弯矩,均与实测结果吻合良好,而采用单参数m法却很难使支护结构的位移和内力同时较好地与实测值相符。反分析所得的综合刚度和地基抗力双参数,可应用于同一基坑工程相同结构或同一地区工程地质条件和支护结构相似的设计计算,无疑可获得较现行单参数法更为准确的设计计算结果。To overcome the defects of the single parameter m method which the current specification recommended, put the composite stiffness principle and hi-parameter method that applied to piles subjected to laterally concentrated loads extended to calculate the deformation and internal force on intemal braces retaining structure in deep excavation. Based on the principle and the method, the modified finite difference solution of beam on elastic foundation was presented. In addition, the incremental method was introduced to consider the dynamic construction process. The composite stiffness EI and bi-parameters m and n were obtained through the back analyses from the field measurement. The result showed that both the calculated horizontal displacement and bending moment by the method proposed in this paper were in good agreement with the measured data. In contrast, the result by the current single-parameter method was unsatisfactory. The parameters obtained through the back analyses can be applied to the uniform structures in the same foundation pit or similar retaining structures and engineering geological conditions in the same areas. Undoubtedly it can obtain more accurate results than the current single parameter method.

关 键 词：基坑工程 内撑式支护结构 综合刚度原理和双参数法 增量法 有限差分算法 

分 类 号：TU47[建筑科学—结构工程]