主跨215 m連續剛構橋施工監控關鍵技術研究

邱云

摘 要：為做好主跨215 m連續剛構橋的施工監控工作，采用遠程無線定時自動采集系統，再結合工況應力增量累計法，實現了應力實測值與理論值較好的相符。同時采用正裝計算法，用Midas Civil軟件建立仿真計算模型，進行了參數敏感性分析，分析結果表明：施工監控采用的仿真計算模型應按實測容重進行施工過程累計撓度的計算;在混凝土齡期滿7天再進行預應力張拉，有利于避免大跨徑連續剛構橋的長期下撓。結合仿真計算和實測結果，溫度修正的理論最大值可采用JTG D60—2015給出的日照溫差分布模式，溫度基數取水泥混凝土鋪裝對應的基數進行仿真計算。采用的立模標高確定方式和預拱度設置方式可供同類工程參考。

關鍵詞：連續剛構橋;施工監控;預拱度;溫度梯度;敏感性分析

中圖分類號：U448.23? ? ? 文獻標識碼：A ? ? ? 文章編號：1003-5168（2021）24-0065-05

Research on Construction Monitor and Control Technology of Continuous Rigid Frame Bridge with Main Span of 215 Meter

QIU Yun

（Foshan Road and Bridge Supervision Station Co.，Ltd.， Foshan Guangdong 528041）

Abstract：In order to achieve the construction monitor and control the continuous rigid frame bridge with main Span of 215 meter， the remote wireless automatic timing acquisition system combined with the working condition of stress increment cumulative method was adopted， and realized the stress measured values are better in conformity with the theoretical value. At the same time， the formal calculation method and Midas Civil software were used to establish a simulation calculation model， and the sensitivity analysis of parameters was carried out. The results show that the simulation calculation model used in construction monitoring should calculate the accumulated deflection in the construction process according to the measured bulk density， and the concrete should be prestressed until it has reached 7 days， the purpose of which is to avoid long-term deflection of long-span continuous rigid frame bridge. According to the simulation calculation and measured results， the theoretical maximum value of temperature correction can be obtained by using the distribution mode of temperature difference given by JTG D60-2015， and the temperature base corresponding to the cement concrete pavement can be used for simulation calculation. The determination method of the elevation and the setting method of the pre-arch can be used as reference for similar projects.

Keywords：continuous rigid frame bridge; construction monitoring and control; camber;temperature gradient; sensitivity analysis

為了確保采用掛籃懸臂澆筑的連續剛構橋施工過程中結構的安全和線形偏差等滿足規范[1]要求，要進行施工監控。施工過程中，對結構安全和線形偏差產生影響的因素很多，這些影響因素的分析和控制方法引起了國內外學者和橋梁工程師的關注和重視。溫度梯度作用對施工監控的標高觀測存在較大影響，但由于地域差異等因素[2-8]，已有標準[9]沒有給出溫度梯度對結構變形測試的修正公式。跨徑在80 m及以上的掛籃施工梁橋的成橋預拱度的設置一般按余弦曲線分配，但最大預拱度的取值還是沒有形成較一致的標準[9，10]。應力測試誤差的消除方法[11]，撓度分析和仿真模型參數調整方法[12]也有研究，也是未形成較一致的標準。本文在已有研究的基礎上，結合實際工程，針對溫度梯度對結構變形的影響、成橋預拱度的設置與應力測試誤差消除的方法進行研究，為后續工程和研究提供參考。