地震作用下大型渡槽結(jié)構(gòu)輸水功能可靠性分析

張威 王博 徐建國 黃亮

摘要：大型鋼筋混凝土渡槽作為生命線類水工結(jié)構(gòu)，其輸水功能可靠性至關(guān)重要。然而，一方面混凝土材料的力學(xué)性能表現(xiàn)出顯著的隨機(jī)性與非線性特征，另一方面渡槽結(jié)構(gòu)在服役期內(nèi)可能遭受不確定的災(zāi)害性地震作用，對渡槽結(jié)構(gòu)的服役安全帶來威脅。為此，采用混凝土隨機(jī)損傷力學(xué)模型量化混凝土隨機(jī)性與非線性耦聯(lián)下渡槽結(jié)構(gòu)的動(dòng)力響應(yīng)，并基于概率密度演化理論給出了渡槽結(jié)構(gòu)輸水功能可靠性分析方法。以某實(shí)際大型鋼筋混凝土渡槽結(jié)構(gòu)為例，詳述了渡槽結(jié)構(gòu)輸水功能可靠性分析的原理和實(shí)現(xiàn)流程。研究表明，概率密度演化理論可以準(zhǔn)確高效地對渡槽結(jié)構(gòu)輸水功能可靠性進(jìn)行評估;不同設(shè)計(jì)水準(zhǔn)下渡槽結(jié)構(gòu)的輸水功能可靠性指標(biāo)存在一定的差異，在設(shè)計(jì)初期應(yīng)予以合理考慮。

關(guān)鍵詞：渡槽;輸水功能;可靠性;隨機(jī)損傷演化;概率密度演化理論;抗震分析

中圖分類號(hào)：TV312;TV672 文獻(xiàn)標(biāo)志碼：A 文章編號(hào)：20966717（2020）04014409

收稿日期：20191010

基金項(xiàng)目：國家自然科學(xué)基金（51579226）;河南省科技攻關(guān)項(xiàng)目（142102310535）

作者簡介：張威（1983 ），男，博士，主要從事結(jié)構(gòu)抗震分析與可靠性研究，Email：zw419064719@163.com。

Received：20191010

Foundation items：National Natural Science Foundation of China （No. 51579226）; Henan Science and Technology Program （No. 142102310535）

Author brief：Zhang Wei（1983 ）， PhD， main research interests： seismic and reliability of structures， Email： zw419064719@163.com.

Waterconveyance functional reliability analysis of largescale aqueduct structures subjected to earthquake excitations

Zhang Wei1， Wang Bo2a， Xu Jianguo2a， Huang Liang2b

（1.School of Engineering Management and Real Estate， Henan University of Economics and Law， Zhengzhou 450046， P.R. China;2a.School of Water Science and Engineering; 2b. School of Civil Engineering， Zhengzhou University， Zhengzhou 450001， P.R. China）

Abstract： Large scale reinforced concrete aqueduct， as a lifeline hydraulic structure， the reliability of its water transport function is very important. However， on one hand， the mechanical property of concrete is equipped with remarkable randomness and nonlinearity. On the other hand， the aqueduct structures may inevitably suffer from uncertain disastrous earthquake actions during service life， posing a great threat to their service safety. To these ends， the present paper proposed a quantification framework for the waterconveyance reliability assessment of the aqueduct structures by incorporating the stochastic damage mechanics model of concrete and the probability density evolution method. The principle and implementation procedures of the developed framework were illustrated in detail on an actual largescale RC aqueduct structure. The results show that the probability density evolution theory can accurately and efficiently evaluate the reliability of aqueduct structure water conveyance function. The waterconveyance reliability varies with the change of predefined seismic fortifications， which should be reasonably accounted for in early design phases.

通過微彈簧的隨機(jī)斷裂可將損傷表示為

式中：Af為斷裂的面積;A0為初始總面積;n表示在當(dāng)前荷載作用下斷裂的彈簧根數(shù);N為彈簧總數(shù);Δi為第i根彈簧的斷裂應(yīng)變;H（·）表示Heaviside函數(shù);ε為應(yīng)變量。

令彈簧總數(shù)趨于無窮，損傷變量可按隨機(jī)積分形式表述為

式中：D為混凝土損傷因子;Δ（x）為一維斷裂應(yīng)變隨機(jī)場;x為空間坐標(biāo)。……