摘要
碾压混凝土坝是近年来被广泛采用的一种筑坝技术,随着建坝数量的增加和规模的日益庞大,带来的温度应力问题更加复杂,从而出现裂缝的可能也在增加。为了引导坝体中的温度裂缝在预定位置开裂,诱导缝作为一种结构措施在许多大型水电工程中都有所应用,并收到了良好的应力释放效果。关于诱导缝的作用机理和破坏准则已经有一些相关报道,但是在实际工程中如何结合模拟诱导缝的作用来分析坝体混凝土的温度场和温度应力场,国内外有关文献中都研究的较少。
本文首先阐述了碾压混凝土坝筑坝材料的热力学性能,并且对混凝土的重要特性之一——徐变——进行了研究,并给出了较为精确的拟合公式和计算程序。另外,文中也对大坝建成蓄水后形成的水库水温进行了详细讨论,通过建立一维的数学模型仿真求解了某水电站建成后的水库水温,为大坝运行期温度场和温度应力场的三维仿真分析给出了准确的边界条件。
本文重点以有限元法对某碾压混凝土拱坝的温度场和温度应力进行三维仿真分析,结合实际工程中设置的诱导缝数量和位置剖分网格,并考虑了不同的浇筑温度、冷却措施等施工条件,共进行了三个典型方案的计算。对计算结果分析后不仅对坝体温度场和温度应力场的分布情况有了明确的认识,而且对诱导缝在释放坝体局部高应力上的作用也进行了阐明。
Roller-compacted concrete dam is a kind of widespread available construction technology in recent years. With the increasing of the quantity and scale of dams, there are such more sophisticated temperature-stress problems that the chances of appearing cracks are growing. For leading temperature-crack of dam concrete to split in the reserved positions, induced-crack was used in many large water-power engineering as a structure measure and gained well-known effectiveness in releasing stress. There are some coherent reports about mechanism of action and failure rules of induced-crack, but it is not enough how to analyze temperature field and temperature-stress field of concrete in dam body with simulating action of induced-crack in actual engineering in recent documents.
In first, the paper sets forth thermal and mechanical performance of materials of RCC dam construction, and study one of important characters of concrete—creep—and gives out relatively exact fitting formula and calculation program. Otherwise, it is detailed discussed water temperature of reservoir after dam completed and impounded. The paper calculates water temperature of actual engineering by establishing linear dimension mathematic model and supplies exact terminal condition for three dimension simulating analysis of temperature field and temperature-stress field in operating period.
The point of the paper is three dimension simulating analysis of temperature field and temperature-stress field of RCC arch dam by FEM. The paper divides meshes according quantity and position of induced-crack and takes in account of different construct conditions to calculate some typical schemes. After we analyzed the calculating results, we have clearly cognitions in distribution of temperature field and temperature-stress field. Furthermore, it illuminates action of induced-crack in releasing local high stress of dam body.
引文
[1] 沈崇刚.中国碾压混凝土坝当前技术进展与运行经验[J].碾压混凝土筑坝技术国际会议论文集(上册).1999年4月,四川成都
[2] 董福品,朱伯芳(1987).碾压混凝土坝温度徐变应力研究[J].水利水电技术,1987年第10期,10-25
[3] 水工设计手册(混凝土坝)[M],水利水电出版社
[4] Goodman R E, Taylor R L, Brekke T L. Model for the mechanic of joint rock[J]. J of the Soil Mechanics and Foundation Division, 1968, 94(3): 660-677.
[5] 李鹏,邹丽春,傅少君,陈胜宏.小湾拱坝诱导缝模拟计算[J].武汉大学学报(工学版),2005,38(3):27-30
[6] 王光纶,张楚汉,郭志松,金峰.设上游底缝改善拱坝应力状态的研究[J].水利学报,1998(1):69-75
[7] Wilson E L. The determination of temperatures within mass concrete structures (SESM Report No.68-17)[J]. Structures and Materials Research, 1968.12.
[8] Tatro, Stephen B, Ernest K. Thermal considerations for roller compacted concrete[J]. Journal of the American Concrete Institute, 1985.4.
[9] Frank J Vecchio. Nonlinear analysis of reinforced concrete frames subjected to thermal and mechanical load[J]. ACI Structural Journal. 1987.
[10] Enrique Mirambell, Antonoi Aguado. Temperature and stress distributions in concrete box girder bridges[J]. Journal of Structural Engineering, 1990.
[11] Mats Emborg, Stig Bemander. Assessment of risk of thermal cracking in hardening concrete[J]. Journal of Structural Engineering, 1994.
[12] Shin, Hak Chul. Early age behavior of bonded concrete overlays due to shrinkage and thermal changes[J]. Engineering, Materials Science, 2000.
[13] D.Pettersson, J.Alemo, S.Thelandersson. Influence on crack development in concrete structures from imposed strains and varying boundary conditions[J]. Construction and Building Materials, 2002.
[14] 朱伯芳.大体积混凝土温度应力与温度控制[M].北京:中国电力出版社,1999.3.
[15] 潘家铮.水工建筑物的温度控制[M].北京:水利电力出版社,1990.11.
[16] 刘光庭,麦家暄,张国新.溪柄碾压混凝土薄拱坝的研究[J].水利发电学报,1997.2.
[17] 赵代深,薄钟禾等.混凝土拱坝应力分析的动态模拟方法[J].水利学报,1994.8.
[18] 黄淑萍等.白莲崖碾压混凝土拱坝温控防裂研究.河海大学,2004.9.
[19] 黄淑萍等.光照碾压混凝土重力坝施工仿真混凝土温控防裂研究.河海大学,2004.12.
[20] 黄淑萍等.云南澜沧江小湾水电站混凝土双曲拱坝施工仿真及温控防裂研究.河海大学.2005.8.
[21] 吴胜兴.混凝土结构的温度应力与温度裂缝控制研究[博士论文].南京:河海大学,1994.6.
[22] 张小刚,宋玉普.碾压混凝土坝诱导缝设置及拱坝诱导缝等效强度[J].水利水运工程学报,2003(4):67-73
[23] 曾昭扬,马黥.高碾压混凝土拱坝的构造缝研究[J].水力发电,1998(2):30-33
[24] 曾昭扬,王燕生.高碾压混凝土拱坝诱导缝和横缝布置研究[R].北京:清华大学,1998.
[25] 钟永江.高碾压混凝土拱坝结构分缝及材料特性研究[J].水力发电,2001(8):17-20
[26] 陈刚,江启升,张林等.碾压混凝土高拱坝分缝形式研究[J].四川大学学报,2000,32(6):15-19
[27] 宋玉普,张林俊,殷福新.碾压混凝土坝诱导缝的断裂分析[J].水利学报,2004(6):21-26
[28] 路纲,宋加国,王智文.碾压混凝土坝诱导缝断裂特性试验研究与分析[J].混凝土,2003(5):25-28
[29] 赵中极,张镜剑,杨耀红.碾压混凝土断裂的数值仿真分析.华北水利水电学报,1995(3):1-7
[30] 吴峰.混凝土温度裂缝仿真系统研究[硕士论文].南京:河海大学,2005.6
[31] 袁勇.混凝土结构早期裂缝控制[M].北京:科学出版社,2004.4
[32] 张璧城.水工建筑物的有限元分析[M].北京:水利电力出版社,1991.11
[33] Lotfi, hamid Reza. Finite element analysis of fracture of concrete and masonry structures[J]. Applied Mechanics,1993.8.
[34] Yao, Budan. Finite element analysis of distributed discrete concrete cracking (crack behavior)[J]. Engineering, Civil, 1993.6.
[35] Shin, Hak-Chul. Early age behavior of bonded concrete overlays due to shrinkage and thermal changes[J]. Engineering, Materials Science, 2000.11.
[36] 南建林,过镇海,时旭东.混凝土的温度-应力耦合本构关系[J].清华大学学报,1997.
[37] 郭之章,傅华.水工建筑物的温度控制[M].北京:水利电力出版社,1990.11
[38] 孟涛,钱晓倩,詹树林,钱匡亮.含有复合胶凝材料的混凝土力学性能及其微观结构机理分析[J].浙江大学学报,2002.9,(5)
[39] 冯伯林,徐道远,周先贵,刘银屏.温度荷载作用下拱坝裂缝的断裂力学分析方法[J].合肥工业大学学报,2000.12,(6)
[40] 邓爱民,张小芹,王向东,徐道远.混凝土拱坝温度裂缝及其扩展稳定性分析[J].河海大学学报,2002.11,(6)
[41] Kenneth, Hansen D. Roller compacted concrete: A civil engineering innovation concrete[J]. International Design & Construction, 1996,18(3): 25-31
[42] 王应军.碾压混凝土坝裂缝成因及防治措施研究[D].大连:大连理工大学,2002.
[43] 杨洪才,陈宗卿.普定水电站碾压混凝土拱坝工程技术总结[J].贵州水力发电,1996(2):8-12
[44] 陈宗卿.普定碾压混凝土拱坝布置和结构设计[J].水力发电,1995(10):5-14
[45] 陈秋华.碾压混凝土拱坝成缝新技术[J].水力发电,2002(1):23-36
[46] 陈秋华,丁予通.沙牌碾压混凝土拱坝结构分缝设计研究[J].水电站设计,2002,13(1):21-25
[47] Xu Shilang, Reihardt H W. Crack extension resistance and fracture properties of quasi-brittle softening materials like concrete based on the complete process of fracture[J]. International Journal of Fracture, 1998, 00: 1-29
[48] 张雪虎,张社荣,陈祖坪.用任意加密有限元剖分的方法研究拱坝强度裂缝的产状[J].水利学报,2001(9):68-73
[49] 王润富,陈国荣.温度场和温度应力[M].北京:科学出版社,2004
[50] 杨忠义等.金沙江溪洛渡水电站可行性研究报告(专题报告三十五:混凝土试验研究总报告).国家电力公司成都勘测设计研究院,2001.12
[51] 黄淑萍等.小湾水电站混凝土拱坝通仓浇筑温度控制技术研究.北京:中国水利水电科学研究院结构所,1995
[52] 丁宝瑛,胡平,黄淑萍.水库水温的近似分析[J].水力发电学报,1987(4)
[53] 黄淑萍等.索风营微膨胀混凝土重力坝补偿温度徐变应力仿真分析.北京:中国水利水电科学研究院,2003
[54] 中华人民共和国水利部.混凝土拱坝设计规范(SL282-2003).中国水利水电出版社.2003.9
[55] 顾爱军,朱为玄,王向东,徐道远.碾压混凝土拱坝诱导缝的断裂力学分析[J].红水河,2004(1):21-24
[56] 顾爱军,王向东,徐道远等.碾压混凝土拱坝诱导缝的作用探讨[J].扬州大学学报自然科学版,2003,6(1):66-70
[57] F. Hollingworth, D.Jhooper, and J.J.Geringer. Roller Compacted Concrete Arched Dams[J]. Water Power & Dam Construction,1989(11): 29-34
[58] Zhu Bofang. Computation of thermal stresses in mass concrete with consideration of creep effect. Fifteenth International Congress on Large Dams,Suisse,Q.57.R.31, 24-28, Junin, 1985
[59] 陈改新,黄国兴,纪国晋.碾压混凝土拱坝的接缝重复灌浆试验研究[J].混凝土坝技术,1999(2):40-45
[60] 尹双增.断裂损伤理论及应用[M].北京:清华大学出版社,1992
[61] 黄达海,宋玉普,赵国藩.碾压混凝土拱坝诱导缝的等效强度研究[J].工程力学,2000(3):16-22
[62] Chang Xiao-lin, Zhou Wei. A contact model on basis of the augmented Lagrange method and engineering application[J]. Chinese Journal of Rock Mechanics and Engineering, 2004(9): 1568-1573
[63] Elwi A A, Murray D W. A 3D hypoelastic concrete constitutive relationship[J]. J Eng Mech Div, ASCE, 1979,105,Em4: 623-641
[64] Bathe K J, Ramaswamy S. On three-dimensional nonlinear analysis of concrete structures[J]. Nul Eng and Design, 1972, 52: 385-409
[65] 廖家煌.万安水电站厂房混凝土温控设计和裂缝情况[J].人民长江,1994(8):13-18
[66] 王威信,邓达华.基于任意六面体单元数据场的可视化研究[J].计算机辅助设计与图形学学报,2000(8):605-608
[67] 邓达华.现代有限元软件系统MAS(第4届全国计算机应用联合学术会议论文集).北京:电子工业出版社,1997:153-156
[68] 谢春,马兰,彭颖红.有限元计算结果的可视化处理[J].计算机辅助设计与图形学学报,2000(2):81-84
[69] 武君胜.有限元分析计算中的可视化技术及实现[J].计算机辅助工程,1995(1):47-51
[70] 张勇等.有限元计算结果的可视化处理[J].CAD技术,1995(6):56-58
[71] 李维特,黄保海,毕仲波.热应力理论分析及应用[M].北京:中国电力出版社,2004