本文選題：碾壓混凝土 + 重力壩�。� 參考：《浙江大學(xué)》2014年碩士論文

【摘要】：近年來碾壓混凝土重力壩在國內(nèi)外的水電工程中被廣泛應(yīng)用,然而壩體在施工期的開裂現(xiàn)象依舊存在,最主要的一個(gè)原因就是溫度應(yīng)力。因此有必要對(duì)壩體進(jìn)行精細(xì)的數(shù)值耦合分析,比較壩體各部位應(yīng)力對(duì)溫度的敏感性。 本文為了驗(yàn)證混凝土強(qiáng)度對(duì)溫度的敏感性,先基于Arrhenius函數(shù)等效齡期方法,進(jìn)行了水工混凝土在不同養(yǎng)護(hù)溫度下的強(qiáng)度試驗(yàn),驗(yàn)證了等效齡期方法的適用性。然后在參考龍灘碾壓混凝土壩原材料試驗(yàn)數(shù)據(jù)資料的基礎(chǔ)上,擬合了碾壓混凝土彈性模量、徐變度、劈裂抗拉強(qiáng)度與齡期之間的相互關(guān)系。根據(jù)碾壓混凝土分層上升澆筑的特點(diǎn),運(yùn)用大型通用有限元ANSYS軟件中的生死單元模塊、參數(shù)化設(shè)計(jì)語言APDL命令流技術(shù),實(shí)現(xiàn)了碾壓混凝土重力壩擋水壩段復(fù)雜隨機(jī)施工過程的數(shù)值模擬,并用現(xiàn)場溫度實(shí)測數(shù)據(jù)加以驗(yàn)證；另外,不同的澆筑溫度和夏季停工因素也在溫度場結(jié)果分析中加以比較。應(yīng)力場分析時(shí),本文首次將普通混凝土中的Arrhenius函數(shù)等效齡期理論引入碾壓混凝土重力壩溫度應(yīng)力場分析中；并因此選擇了2種不同的計(jì)算方案,以對(duì)比實(shí)際齡期、等效齡期這2種計(jì)算方案對(duì)壩段應(yīng)力場分布的不同影響,并采用開裂系數(shù)評(píng)價(jià)壩體各部位開裂風(fēng)險(xiǎn)對(duì)溫度的敏感性,從而反映溫度對(duì)碾壓混凝土壩體材料性能的影響。 計(jì)算結(jié)果表明,考慮等效齡期時(shí),相比實(shí)際齡期,能大幅度減少各高程節(jié)點(diǎn)拉應(yīng)力峰值。而不管采用何種方案,高溫季節(jié)施工層面的外部節(jié)點(diǎn)都有較明顯的拉應(yīng)力峰值,而低溫季節(jié)施工層面的外部節(jié)點(diǎn)拉應(yīng)力峰值則很小。 考慮實(shí)際齡期時(shí),施工期y方向應(yīng)力最大值均出現(xiàn)在壩體的基礎(chǔ)強(qiáng)約束區(qū)。而考慮等效齡期時(shí),y方向應(yīng)力呈現(xiàn)明顯的縱向分布特征,而不再是沿壩高方向的季節(jié)性特征,基礎(chǔ)強(qiáng)約束區(qū)和基礎(chǔ)弱約束區(qū)y方向應(yīng)力值也較小。 考慮實(shí)際齡期時(shí),基礎(chǔ)強(qiáng)約束區(qū)中心節(jié)點(diǎn)沿y方向的后期開裂指數(shù)較大,如果不采取防護(hù)措施,就會(huì)產(chǎn)生基礎(chǔ)部位水平裂縫。當(dāng)考慮等效齡期時(shí),各高程中心節(jié)點(diǎn)均不會(huì)發(fā)生沿順河向的垂直裂縫,更絕對(duì)不會(huì)在碾壓層面產(chǎn)生水平裂縫。 等效齡期的計(jì)算方法重新評(píng)估了壩段各部位尤其是基礎(chǔ)強(qiáng)約束區(qū)的開裂風(fēng)險(xiǎn),表明溫度對(duì)碾壓混凝土重力壩材料性能和各部位的應(yīng)力分布有著明顯影響。
[Abstract]:In recent years, RCC gravity dams have been widely used in hydropower projects at home and abroad. However, the cracking of the dam body during the construction period still exists, one of the main reasons is the temperature stress. Therefore, it is necessary to carry on the fine numerical coupling analysis to the dam body, and to compare the sensitivity of the stress of each part of the dam body to the temperature. In order to verify the temperature sensitivity of concrete strength, based on the Arrhenius function equivalent age method, the strength tests of hydraulic concrete at different curing temperatures are carried out, and the applicability of the equivalent age method is verified. Based on the experimental data of RCC dam, the relationship between the elastic modulus, creep degree, splitting tensile strength and age of RCC is fitted. According to the characteristics of RCC layered upward pouring, using the birth and death element module in the large-scale finite element ANSYS software, the parameterized design language APDL command flow technology is used. The numerical simulation of complex random construction process of RCC gravity dam section is realized and verified by field temperature data. In addition, different pouring temperatures and summer shutdown factors are compared in the analysis of temperature field results. When the stress field is analyzed, the equivalent age theory of Arrhenius function in ordinary concrete is introduced into the analysis of thermal stress field of RCC gravity dam for the first time, and two different calculation schemes are selected to compare the actual age of RCC gravity dam. The two calculation schemes of equivalent age have different effects on the stress field distribution of the dam segment, and the cracking coefficient is used to evaluate the sensitivity of the cracking risk of the dam body to the temperature so as to reflect the influence of temperature on the material properties of the RCC dam body. The results show that when the equivalent age is considered, the peak tensile stress of each elevation node can be greatly reduced compared with the actual age. However, no matter what scheme is adopted, the peak tensile stress of the external node at the construction level in the high temperature season is obvious, but the peak value of the tensile stress in the construction layer in the low temperature season is very small. When considering the actual age, the maximum value of stress in the direction of y appears in the strong restraint zone of the dam foundation during the construction period. Considering the equivalent age, the stress in the y direction shows obvious longitudinal distribution, but is no longer seasonal along the direction of the height of the dam, and the stress value in the y direction of the strong constraint zone and the weak constraint zone of the foundation is also smaller. When considering the actual age, the later cracking index of the center node in the strong restraint zone of the foundation along the y direction is large, and if the protective measures are not taken, the horizontal crack in the foundation will occur. When the equivalent age is considered, the vertical cracks along the river direction will not occur in each elevation center node, and the horizontal cracks will not be produced in the rolling layer. The calculation method of equivalent age reevaluates the cracking risk in every part of dam section, especially in the strongly confined zone of foundation. It shows that temperature has a significant effect on the material performance and stress distribution of RCC gravity dam.
【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TV642;TV315

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 石妍,方坤河;碾壓混凝土抗拉強(qiáng)度的規(guī)律分析[J];大壩與安全;2005年02期

2 ;裂縫重力壩應(yīng)力應(yīng)變數(shù)值分析[J];大連工學(xué)院學(xué)報(bào);1973年03期

3 黃達(dá)海,殷福新,宋玉普;碾壓混凝土壩溫度場仿真分析的波函數(shù)法[J];大連理工大學(xué)學(xué)報(bào);2000年02期

4 卓旬;梅明榮;;混凝土徐變計(jì)算理論和方法綜述[J];水利與建筑工程學(xué)報(bào);2012年02期

5 姜冬菊,張子明,王德信;計(jì)算溫度應(yīng)力的廣義約束矩陣法[J];河海大學(xué)學(xué)報(bào)(自然科學(xué)版);2003年01期

6 張子明,馮樹榮,石青春,王嘉航;基于等效時(shí)間的混凝土絕熱溫升[J];河海大學(xué)學(xué)報(bào)(自然科學(xué)版);2004年05期

7 程多松;尚建麗;孫立春;宗偉;;輕集料混凝土早期強(qiáng)度預(yù)測的試驗(yàn)研究[J];混凝土;2007年01期

8 王建江，陸述遠(yuǎn)，魏錦萍;RCCD溫度應(yīng)力分析的非均勻單元方法[J];力學(xué)與實(shí)踐;1995年03期

9 石妍;方坤河;高鐘偉;;碾壓混凝土強(qiáng)度特性的研究[J];水力發(fā)電學(xué)報(bào);2006年01期

10 朱伯芳;多層混凝土結(jié)構(gòu)仿真應(yīng)力分析的并層算法[J];水力發(fā)電學(xué)報(bào);1994年03期

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