主跨215 m連續(xù)剛構(gòu)橋施工監(jiān)控關(guān)鍵技術(shù)研究

邱云

摘 要：為做好主跨215 m連續(xù)剛構(gòu)橋的施工監(jiān)控工作，采用遠(yuǎn)程無(wú)線定時(shí)自動(dòng)采集系統(tǒng)，再結(jié)合工況應(yīng)力增量累計(jì)法，實(shí)現(xiàn)了應(yīng)力實(shí)測(cè)值與理論值較好的相符。同時(shí)采用正裝計(jì)算法，用Midas Civil軟件建立仿真計(jì)算模型，進(jìn)行了參數(shù)敏感性分析，分析結(jié)果表明：施工監(jiān)控采用的仿真計(jì)算模型應(yīng)按實(shí)測(cè)容重進(jìn)行施工過(guò)程累計(jì)撓度的計(jì)算;在混凝土齡期滿7天再進(jìn)行預(yù)應(yīng)力張拉，有利于避免大跨徑連續(xù)剛構(gòu)橋的長(zhǎng)期下?lián)稀＝Y(jié)合仿真計(jì)算和實(shí)測(cè)結(jié)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(shù)取水泥混凝土鋪裝對(duì)應(yīng)的基數(shù)進(jìn)行仿真計(jì)算。采用的立模標(biāo)高確定方式和預(yù)拱度設(shè)置方式可供同類(lèi)工程參考。

關(guān)鍵詞：連續(xù)剛構(gòu)橋;施工監(jiān)控;預(yù)拱度;溫度梯度;敏感性分析

中圖分類(lèi)號(hào)：U448.23? ? ? 文獻(xiàn)標(biāo)識(shí)碼：A ? ? ? 文章編號(hào)：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(xù)剛構(gòu)橋施工過(guò)程中結(jié)構(gòu)的安全和線形偏差等滿足規(guī)范[1]要求，要進(jìn)行施工監(jiān)控。施工過(guò)程中，對(duì)結(jié)構(gòu)安全和線形偏差產(chǎn)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(guó)內(nèi)外學(xué)者和橋梁工程師的關(guān)注和重視。溫度梯度作用對(duì)施工監(jiān)控的標(biāo)高觀測(cè)存在較大影響，但由于地域差異等因素[2-8]，已有標(biāo)準(zhǔn)[9]沒(méi)有給出溫度梯度對(duì)結(jié)構(gòu)變形測(cè)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(yù)拱度的設(shè)置一般按余弦曲線分配，但最大預(yù)拱度的取值還是沒(méi)有形成較一致的標(biāo)準(zhǔn)[9，10]。應(yīng)力測(cè)試誤差的消除方法[11]，撓度分析和仿真模型參數(shù)調(diào)整方法[12]也有研究，也是未形成較一致的標(biāo)準(zhǔn)。本文在已有研究的基礎(chǔ)上，結(jié)合實(shí)際工程，針對(duì)溫度梯度對(duì)結(jié)構(gòu)變形的影響、成橋預(yù)拱度的設(shè)置與應(yīng)力測(cè)試誤差消除的方法進(jìn)行研究，為后續(xù)工程和研究提供參考。