空腹重力壩體型優(yōu)化及施工期溫度場(chǎng)應(yīng)力場(chǎng)仿真分析
發(fā)布時(shí)間：2018-10-12 09:31
【摘要】：空腹重力壩因其具有減小揚(yáng)壓力、降低混凝土工程量、利于施工期散熱等優(yōu)點(diǎn)被國(guó)內(nèi)外廣泛采用。然而,該壩型的相關(guān)研究仍有不足之處。首先,空腹重力壩的優(yōu)化設(shè)計(jì)仍處在方案比選階段,有進(jìn)一步優(yōu)化的空間;其次,其便于散熱的特點(diǎn)始終未得到重視,施工過(guò)程仿真分析也一直處于空白。而近年來(lái),碾壓混凝土的應(yīng)用越來(lái)越普遍,這種施工技術(shù)應(yīng)用于空腹重力壩已成為必然趨勢(shì)。所以本文以碾壓混凝土空腹重力壩作為研究對(duì)象,借助ANSYS軟件平臺(tái),綜合考慮溫度、碾壓混凝土施工特點(diǎn)等影響因素。一方面提出了空腹重力壩的最優(yōu)結(jié)構(gòu)形式,另一方面通過(guò)施工過(guò)程熱-應(yīng)力耦合場(chǎng)仿真分析,探索了利用空腹散熱的實(shí)際效果。論文共分為5個(gè)章節(jié),從理論到實(shí)踐展開(kāi)研究論述。第一章為緒論,主要對(duì)論文研究背景、研究意義、研究?jī)?nèi)容、研究方法、研究框架進(jìn)行整合。第二章為仿真分析理論綜述。第三章基于空腹重力壩復(fù)雜多樣的腹孔形式,建立能夠完整表達(dá)各典型斷面的優(yōu)化數(shù)學(xué)模型,借助ANSYS優(yōu)化模塊對(duì)腹孔結(jié)構(gòu)各參數(shù)進(jìn)行一次性?xún)?yōu)化,確定最優(yōu)的斷面類(lèi)型和結(jié)構(gòu)尺寸;第四章基于優(yōu)化斷面進(jìn)行施工過(guò)程模擬,耦合溫度與應(yīng)力場(chǎng),以相同條件下實(shí)體重力壩作為參照,比較了空腹重力壩相比實(shí)體重力壩的散熱效果,得到了施工期不同空腹溫度條件下壩體溫度場(chǎng)變化規(guī)律;第五章為結(jié)論,對(duì)本文研究成果進(jìn)行提煉總結(jié)。主要成果如下:(1)應(yīng)用ANSYS優(yōu)化模塊對(duì)空腹重力壩典型斷面(城門(mén)洞型、扇形、上下游斜墻均向上游傾斜型)進(jìn)行優(yōu)化。針對(duì)空腹重力壩與壩基接觸面積小且受溫度影響較大的特點(diǎn),在優(yōu)化過(guò)程中,采用熱固耦合法和接觸單元法分析溫度荷載及壩體抗滑穩(wěn)定問(wèn)題。結(jié)果表明,上下游斜墻均向上游傾斜型的布局使空腹走向與壩體內(nèi)部合力方向相同,從而顯著的改善了空腹周?chē)膽?yīng)力條件;且由于空腹重力壩與基巖面的接觸面積較小,尋優(yōu)過(guò)程中不宜減小壩底長(zhǎng)度,應(yīng)將增大空腹高度作為減小工程量的主要手段。經(jīng)優(yōu)化,斷面面積減少約13.6%,優(yōu)化斷面上下游斜墻與水平面夾角72~76度。以相同的優(yōu)化過(guò)程,設(shè)置5種類(lèi)型的基巖參數(shù),得到不同壩基條件下優(yōu)化斷面的控制條件及變化規(guī)律,為不同地質(zhì)條件下的壩體斷面尺寸比選提供參考。在優(yōu)化結(jié)果的基礎(chǔ)上,將空腔替換為填渣開(kāi)展進(jìn)一步的優(yōu)化,結(jié)果表明:填渣結(jié)構(gòu)不僅能夠?yàn)槭┕ぬ峁O大地便利,其對(duì)壩體抗滑穩(wěn)定狀態(tài)的提升作用可以使空腹重力壩優(yōu)化斷面面積進(jìn)一步減小。(2)根據(jù)實(shí)際工程資料,對(duì)采用優(yōu)化后截面的壩體進(jìn)行施工全過(guò)程仿真計(jì)算,綜合考慮外界氣溫和壩體分層等因素,運(yùn)用有限元數(shù)值分析法模擬施工過(guò)程中溫度場(chǎng)的變化。在計(jì)算結(jié)果的基礎(chǔ)上,以控制空腹內(nèi)溫度作為溫控措施,設(shè)置不同方案,進(jìn)行仿真計(jì)算,分析各方案間的差別及對(duì)壩體的影響程度。結(jié)果表明,空腹重力壩施工完成時(shí)內(nèi)部最高溫度28.88度,相比實(shí)體重力壩下降5.56度,內(nèi)外溫差降低約40%。完建期實(shí)體壩最大拉應(yīng)力0.613Mpa,空腹壩0.354Mpa,下降0.259Mpa�？崭箟斡捎谏嵝阅芎�,產(chǎn)生的內(nèi)部溫升低,且與基巖接觸面積較小,建設(shè)期的溫度應(yīng)力狀態(tài)較實(shí)體重力壩更為理想。但空腹重力壩拉應(yīng)力主要出現(xiàn)在空腹頂拱處,在實(shí)際工程中應(yīng)通過(guò)配筋等工程措施進(jìn)行加強(qiáng)處理。本文的主要?jiǎng)?chuàng)新點(diǎn):一、建立了包含多種典型斷面的空腹重力壩通用數(shù)學(xué)優(yōu)化模型,在優(yōu)化過(guò)程中考慮溫度荷載和壩體與基巖的接觸問(wèn)題,并對(duì)施工過(guò)程中采用了空腹填渣技術(shù)的壩體進(jìn)行了結(jié)構(gòu)分析。二、分析總結(jié)了空腹重力壩便于混凝土散熱特點(diǎn)的實(shí)際效果,并首次提出利用空腹結(jié)構(gòu)散熱作為壩體的溫控措施。
[Abstract]:The hollow gravity dam has the advantages of reducing the uplift pressure, reducing the quantity of concrete, facilitating the heat dissipation in the construction period and the like, and is widely adopted at home and abroad. However, there are still some deficiencies in the study of the dam type. Firstly, the optimization design of the hollow gravity dam is still in the scheme ratio selection stage, there is further optimized space; secondly, it is convenient for the heat dissipation characteristic is not paid attention all the time, the construction process simulation analysis has been in the blank. In recent years, the application of roller compacted concrete has become more and more common, and this construction technology has become an inevitable trend. Therefore, as the research object of the rolling concrete hollow gravity dam, the factors such as the temperature and the construction characteristics of RCC are comprehensively considered by means of the software platform of ANSYS. On the one hand, the optimal structure of the hollow gravity dam is put forward, on the other hand, through the simulation analysis of the thermal-stress coupling field during the construction process, the practical effect of using the hollow heat dissipation is explored. The thesis is divided into five chapters, from theory to practice. The first chapter is the introduction, the research background, the research significance, the research content, the research method and the research framework of the thesis. The second chapter is an overview of the theory of simulation analysis. The third chapter is based on the complex and diverse abdominal hole form of an empty gravity dam, establishes an optimized mathematical model which can fully express each typical section, optimizes the parameters of the abdominal hole structure by means of the ANSYS optimization module, and determines the optimal section type and the structure size; In the fourth chapter, on the basis of the optimization section, the simulation, coupling temperature and stress field of the concrete gravity dam under the same condition are compared, and the heat radiation effect of the solid gravity dam is compared with the hollow gravity dam, and the temperature field change rule of the dam body under different fasting temperature conditions during the construction period is obtained. The fifth chapter concludes that the research results are summarized. The main results are as follows: (1) The optimization module of ANSYS is applied to optimize the typical section of hollow gravity dam (urban door opening type, sector, upstream and downstream inclined walls). Aiming at the characteristics of small contact area between hollow gravity dam and dam foundation and great influence of temperature, thermal solid coupling method and contact unit are used to analyze the temperature load and anti-slip stability of dam body during the optimization process. The results show that both the upstream inclined wall and the upstream inclined wall incline to the same direction as the inner force direction of the dam body, so that the stress condition around the empty stomach is obviously improved, and because the contact area between the hollow gravity dam and the bedrock surface is small, the bottom length of the dam should not be reduced during the optimization process, The increased fasting height should be used as the main means of reducing the amount of work. After optimization, the section area is reduced by about 13. 6%, and the angle between the inclined wall and the horizontal plane at the upper and lower reaches of the optimized section is 72 ~ 76 degrees. Based on the same optimization process, five types of bedrock parameters are set to obtain the control condition and rule of the optimized section under different dam foundation conditions, and provide reference for the size ratio of the dam section under different geological conditions. On the basis of the optimization results, the cavity is replaced with filling slag to carry out further optimization, and the results show that the slag filling structure can not only provide great convenience for the construction, but also can further reduce the optimized cross-section area of the hollow gravity dam by the lifting action of the anti-sliding stability state of the dam body. (2) According to the actual engineering data, the whole process simulation calculation of the dam body with optimized cross section is carried out, the factors such as external air temperature and dam body stratification are comprehensively considered, and the change of the temperature field during the construction process is simulated by using the finite element numerical analysis method. On the basis of the calculation result, different schemes are set up to control the temperature in the empty stomach as the temperature control measure, and the simulation calculation is carried out, and the difference between the schemes and the degree of influence on the dam body are analyzed. The results show that the internal maximum temperature is 28. 88 degrees in the completion of the construction of the empty gravity dam, and the difference of the internal and external temperature difference is reduced by about 40% compared with that of the solid gravity dam. The maximum tensile stress of the solid dam during the construction period is 0. 613Mpa, the empty dam is 0.354Mpa, and the drop is 0. 259Mpa. Due to the good heat dissipation performance of the hollow dam, the generated internal temperature rise is low, and the contact area with the bedrock is small, and the temperature stress state during the construction period is more ideal than that of the solid gravity dam. However, the tensile stress of the hollow gravity dam mainly occurs at the hollow top arch, and the reinforcement treatment shall be carried out through the engineering measures such as reinforcing bars in the actual project. The main innovation points in this paper are: firstly, a general mathematical optimization model of an empty gravity dam containing multiple typical sections is established, the contact problem between the temperature load and the dam body and the bedrock is considered during the optimization process, and the structure analysis of the dam body adopting the empty filling slag technology is adopted in the construction process. Secondly, the practical effect of the hollow gravity dam to facilitate the heat dissipation of concrete is analyzed, and the temperature control measures for the dam body using the hollow structure heat dissipation are put forward for the first time.
【學(xué)位授予單位】：西北農(nóng)林科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：TV642.3;TV544
[Abstract]:The hollow gravity dam has the advantages of reducing the uplift pressure, reducing the quantity of concrete, facilitating the heat dissipation in the construction period and the like, and is widely adopted at home and abroad. However, there are still some deficiencies in the study of the dam type. Firstly, the optimization design of the hollow gravity dam is still in the scheme ratio selection stage, there is further optimized space; secondly, it is convenient for the heat dissipation characteristic is not paid attention all the time, the construction process simulation analysis has been in the blank. In recent years, the application of roller compacted concrete has become more and more common, and this construction technology has become an inevitable trend. Therefore, as the research object of the rolling concrete hollow gravity dam, the factors such as the temperature and the construction characteristics of RCC are comprehensively considered by means of the software platform of ANSYS. On the one hand, the optimal structure of the hollow gravity dam is put forward, on the other hand, through the simulation analysis of the thermal-stress coupling field during the construction process, the practical effect of using the hollow heat dissipation is explored. The thesis is divided into five chapters, from theory to practice. The first chapter is the introduction, the research background, the research significance, the research content, the research method and the research framework of the thesis. The second chapter is an overview of the theory of simulation analysis. The third chapter is based on the complex and diverse abdominal hole form of an empty gravity dam, establishes an optimized mathematical model which can fully express each typical section, optimizes the parameters of the abdominal hole structure by means of the ANSYS optimization module, and determines the optimal section type and the structure size; In the fourth chapter, on the basis of the optimization section, the simulation, coupling temperature and stress field of the concrete gravity dam under the same condition are compared, and the heat radiation effect of the solid gravity dam is compared with the hollow gravity dam, and the temperature field change rule of the dam body under different fasting temperature conditions during the construction period is obtained. The fifth chapter concludes that the research results are summarized. The main results are as follows: (1) The optimization module of ANSYS is applied to optimize the typical section of hollow gravity dam (urban door opening type, sector, upstream and downstream inclined walls). Aiming at the characteristics of small contact area between hollow gravity dam and dam foundation and great influence of temperature, thermal solid coupling method and contact unit are used to analyze the temperature load and anti-slip stability of dam body during the optimization process. The results show that both the upstream inclined wall and the upstream inclined wall incline to the same direction as the inner force direction of the dam body, so that the stress condition around the empty stomach is obviously improved, and because the contact area between the hollow gravity dam and the bedrock surface is small, the bottom length of the dam should not be reduced during the optimization process, The increased fasting height should be used as the main means of reducing the amount of work. After optimization, the section area is reduced by about 13. 6%, and the angle between the inclined wall and the horizontal plane at the upper and lower reaches of the optimized section is 72 ~ 76 degrees. Based on the same optimization process, five types of bedrock parameters are set to obtain the control condition and rule of the optimized section under different dam foundation conditions, and provide reference for the size ratio of the dam section under different geological conditions. On the basis of the optimization results, the cavity is replaced with filling slag to carry out further optimization, and the results show that the slag filling structure can not only provide great convenience for the construction, but also can further reduce the optimized cross-section area of the hollow gravity dam by the lifting action of the anti-sliding stability state of the dam body. (2) According to the actual engineering data, the whole process simulation calculation of the dam body with optimized cross section is carried out, the factors such as external air temperature and dam body stratification are comprehensively considered, and the change of the temperature field during the construction process is simulated by using the finite element numerical analysis method. On the basis of the calculation result, different schemes are set up to control the temperature in the empty stomach as the temperature control measure, and the simulation calculation is carried out, and the difference between the schemes and the degree of influence on the dam body are analyzed. The results show that the internal maximum temperature is 28. 88 degrees in the completion of the construction of the empty gravity dam, and the difference of the internal and external temperature difference is reduced by about 40% compared with that of the solid gravity dam. The maximum tensile stress of the solid dam during the construction period is 0. 613Mpa, the empty dam is 0.354Mpa, and the drop is 0. 259Mpa. Due to the good heat dissipation performance of the hollow dam, the generated internal temperature rise is low, and the contact area with the bedrock is small, and the temperature stress state during the construction period is more ideal than that of the solid gravity dam. However, the tensile stress of the hollow gravity dam mainly occurs at the hollow top arch, and the reinforcement treatment shall be carried out through the engineering measures such as reinforcing bars in the actual project. The main innovation points in this paper are: firstly, a general mathematical optimization model of an empty gravity dam containing multiple typical sections is established, the contact problem between the temperature load and the dam body and the bedrock is considered during the optimization process, and the structure analysis of the dam body adopting the empty filling slag technology is adopted in the construction process. Secondly, the practical effect of the hollow gravity dam to facilitate the heat dissipation of concrete is analyzed, and the temperature control measures for the dam body using the hollow structure heat dissipation are put forward for the first time.
【學(xué)位授予單位】：西北農(nóng)林科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：TV642.3;TV544
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相關(guān)期刊論文 前10條
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