周勇,胡玉丽. 2021. 基于改进增量法的桩锚支护结构位移与内力计算[J]. 工程地质学报,29(1):229-236. doi:10.13544/j.cnki.jeg.2020-039. DOI: 10.13544/j.cnki.jeg.2020-039
    引用本文: 周勇,胡玉丽. 2021. 基于改进增量法的桩锚支护结构位移与内力计算[J]. 工程地质学报,29(1):229-236. doi:10.13544/j.cnki.jeg.2020-039. DOI: 10.13544/j.cnki.jeg.2020-039
    Zhou Yong, Hu Yuli. 2021. Calculation for displacement and internal force of pile anchor retaining structure based on improved increment method[J]. Journal of Engineering Geology, 29(1): 229-236. doi: 10.13544/j.cnki.jeg.2020-039.
    Citation: Zhou Yong, Hu Yuli. 2021. Calculation for displacement and internal force of pile anchor retaining structure based on improved increment method[J]. Journal of Engineering Geology, 29(1): 229-236. doi: 10.13544/j.cnki.jeg.2020-039.

    基于改进增量法的桩锚支护结构位移与内力计算

    CALCULATION FOR DISPLACEMENT AND INTERNAL FORCE OF PILE ANCHOR RETAINING STRUCTURE BASED ON IMPROVED INCREMENT METHOD

    • 摘要: 在基坑设计计算中,就深基坑桩锚支护结构的受力与变形研究而言,目前运用较为广泛的是改进增量法理论,荷载增量的准确计算是该理论是否应用于实践的关键点,荷载增量的计算中是否应考虑开挖面以下土体因抗力系数变动引起弹性抗力变化释放的反力增量成为研究焦点,而对土体弹性抗力的影响因素却少有研究。鉴于此,本文在计算荷载增量时,综合考虑位移土压力及开挖面以下土体因抗力系数变动引起弹性抗力变化的影响,提出了更符合工程实际的增量计算方法。结合工程实例,编制了MATLAB计算程序,将其所得结果与未考虑前进行了对比,并进一步采用有限元软件PLAXIS对工程实例进行模拟,验证了此方法的合理性,结果表明本文提出的基于改进增量法的桩锚支护结构位移与内力计算方法是合理、可行的。最后对影响土体弹性抗力的两大因素——土体黏聚力c与内摩擦角φ,通过控制变量法分别进行了讨论分析,结果显示随着土体黏聚力c或内摩擦角φ的减小,桩身位移呈现逐渐增大的趋势,但最大位移都在基坑变形允许的范围内。

       

      Abstract: At present, the improved incremental method is widespread in the study of the internal force and deformation of the pile anchor retaining structure for deep excavation. The precise calculation of load increment plays a key role in applying this method into practice. Most of the researchers focus on the reaction increment of the soil below the excavated surface and released due to the soil elastic resistance change caused by resistance coefficient change. However, there are few studies on the influencing factors of soil elastic resistance. Therefore, we used the earth pressure considering displacement and considered the influence of the change of the elastic resistance caused by the change of the resistance factor of the soil below the excavation surface. We proposed an incremental calculation method that was more in line with the actual engineering. Then we compiled a MATLAB calculation program based on the engineering example and compared the results of the program with those before consideration. Furthermore, we adopted PLAXIS to simulate the engineering example to verify the rationality of this method. The results show that the calculation method for displacement and internal force of pile anchor retaining structure based on improved incremental method is reasonable and feasible. Finally, we used the method of control variable to discuss two factors that affected the soil elastic resistance—the cohesion of soil and the internal friction angle of soil. The results show that as the decrease of the cohesion of soil and the internal friction angle of soil, the displacement of pile shows a trend of increasing, but the maximum displacement is always within the allowable range of deep excavation deformation.

       

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