考虑非荷载因素影响的混凝土支撑轴力研究

Study on Axial Force of Concrete Support Considering Influence of Non-load Factors

混凝土支撑是深基坑工程中重要的支护结构,在对其进行现场监测时,由于轴力监测元器件安装保护不到位,混凝土干缩、徐变及温度变化等诸多非荷载因素的影响往往使得轴力监测数值产生较大偏差,因此需要对非荷载因素产生的影响进行研究分析,使轴力监测数值更贴近其真实受力值。以济南市某工程为依托,通过理论分析、现场监测及试验研究相结合的技术手段,研究非荷载因素对支撑轴力的影响,主要得到以下的研究成果。(1)通过对混凝土支撑测点埋设及保护进行系统阐述,规范了混凝土支撑轴力监测元器件在安装过程中施工工艺,解决了混凝土支撑轴力监测数据异常根源方面的问题。(2)通过对混凝土支撑轴力计算原理和现场轴力监测结果进行论述,分析了混凝土支撑轴力整体变化趋势,可针对轴力变化较为剧烈的施工薄弱阶段进行重点防护,为基坑工程的安全性提供保障。(3)最后针对现场轴力监测数据异常现象进行了分析,并通过现场浇筑试验梁的方式对非荷载因素进行了试验研究与轴力数值的修正,满足了基坑监测数据准确性和指导性的要求。

Concrete support is important supporting structure of deep foundation pit engineering,when carries on the field monitoring,because of the axial force monitoring components installed protection does not reach the designated position,concrete shrinkage,creep and temperature change,and many other non load factors tend to make larger axial force monitoring numerical produces deviation,so it is necessary to study the impact of the load factor analysis,makes the axial force monitoring values closer to the real stress value.This paper takes the jinan economy yet wear yellow road tunnel project as the backing,through theoretical analysis,field monitoring and experimental study on the combination of technology,research the load factor's influence on the strut axial forces,basically have the following findings(.1)through the concrete support point embedding and protection system,standardize the concrete strut axial forces monitoring components in the process of installation construction technology,to solve the concrete strut axial forces monitoring data of abnormal root cause problems.(2)By discussing the calculation principle of concrete support axial force and field axial force monitoring results,the overall variation trend of concrete support axial force is analyzed,which can be used to carry out key protection for the weak stage of construction where the axial force changes more violently,and provide guarantee for the safety of foundation pit engineering.(3)Finally,the abnormal phenomena of the field axial force monitoring data were analyzed,and the nonload factors were tested and the axial force values were corrected by pouring the test beam on site,which met the requirements of the accuracy and guidance of the foundation pit monitoring data.