【摘要】：建設(shè)中的滬通長(zhǎng)江大橋28~#主墩承臺(tái)混凝土澆筑量多達(dá)4.2萬(wàn)m~3,需采取溫度控制措施。本文結(jié)合現(xiàn)場(chǎng)條件開展數(shù)值模擬分析,確定在夏季直曬高溫條件下承臺(tái)混凝土的最大絕熱溫升、冷卻水管對(duì)流換熱系數(shù)等關(guān)鍵參數(shù),以及承臺(tái)混凝土各控制點(diǎn)的溫度-時(shí)間曲線。計(jì)算結(jié)果表明,若使承臺(tái)混凝土溫度控制指標(biāo)滿足設(shè)計(jì)要求,則承臺(tái)混凝土澆筑后2~3 d內(nèi),作為溫度控制主要工程措施的冷卻水(溫度為25℃左右)流速應(yīng)≥1.5 m/s;達(dá)到峰值溫度以后流速降低為1 m/s;隨時(shí)間和混凝土內(nèi)部溫度變化流速可繼續(xù)降低;通水降溫時(shí)長(zhǎng)應(yīng)≥7 d。數(shù)值模擬結(jié)果可用于指導(dǎo)承臺(tái)大體積混凝土的施工。
[Abstract]:The concrete pouring capacity of the bearing cap of the main pier 28# of the Hutong Yangtze River Bridge under construction is up to 42000 mm3, so temperature control measures should be taken. In this paper, the maximum adiabatic temperature rise of cap concrete and the convection heat transfer coefficient of cooling water pipe are determined under the condition of direct drying and high temperature in summer. And the temperature-time curve of each control point of cap concrete. The calculation results show that if the temperature control index of the cap concrete meets the design requirements, the concrete of the cap can be poured within 2 ~ 3 days. The velocity of cooling water (about 25 鈩，

本文編號(hào)：2201415