应力应变监控技术在管道桁架跨越中的应用

大跨度管道桁架跨越多采用牵引（顶推）方法施工,但施工荷载和外界因素导致桁架杆件产生复杂的应力状态,因而过程控制对整个施工成败具有关键作用。以境外某管道桁架跨越工程为例,从桥路选择、数据采集系统、施工过程数值模拟计算、传感器选择与安装等方面详细论述了应力应变监控技术在该工程中的应用。监控结果显示桁架最大应力为121 MPa,经现场及时调整牵引速度后,桁架应力稳定在90 MPa以内,与计算值基本吻合。应力应变监控技术能够及时、准确地提供关键结构部位的受力情况,具有较强的可实施性,可以有效保障工程施工的安全。

Stress-strain monitoring technology used in truss overhead crossing installation of pipeline

The installation for truss overhead crossing of large span pipeline is mostly made with pulling (jacking) method, the stress applied on the truss members is complex due to impact of installation load and external factors, and process control plays a critical role in installation. Taking a truss overhead crossing project abroad as an example, the application of stress-stain monitoring technology in selection of bridge route, data acquisition system, numerical simulation calculation of installation process, selection and installation of sensors, etc. is discussed in detail. The monitoring results show that the maximum stress of a truss is 121 MPa, after field adjustment of pulling speed, the stress of truss is stable within 90 MPa, which is basically consistent with calculated value. The stress-strain monitoring technology is able to provide force condition applied on critical structure locations, with strong feasibility of implementation and can ensure installation safety effectively.