高压水荷载下井壁混凝土力学性能试验研究
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摘要
随着浅部煤炭资源渐趋枯竭,为确保煤炭工业的可持续发展,需进行深部煤炭开发。目前,有的井筒深度已达到1000米,而在黄淮地区新井建设时井筒将要穿过深厚冲积层。随着井筒穿过冲积层厚度的增加,井壁承受的水压力也越来越大,由此而带来井壁在高压水荷载作用下的安全使用问题。因此,对井壁混凝土在高压水作用下的力学性能研究很有必要。
通过对深厚表土层冻结井壁实际受力状态的分析,指出在冻结壁解冻后,高压水荷载将直接作用在井壁上,因此,在井壁结构分析中应考虑高压水荷载直接作用下混凝土的力学特性。
在试验研究方面,利用安徽理工大学地下工程结构研究所的液压加载装置进行,混凝土试件采用100mm×100mm×100mm的立方体试件,试验中考虑了不同的加载方式(有水和无水作用)和不同的水荷载大小对试件强度的影响。试验的水荷载作用方式分为试件密封和试件不密封两种。水荷载大小分别为0、3MPa和5MPa。为了分析混凝土的强度等级对混凝土抗压强度的影响,分别采用C50、C60、C70的混凝土标准试件在0、3MPa、5MPa围压下,对混凝土的抗压强度进行试验。试验结果表明,在密封条件下(高压水荷载间接作用下),混凝土的抗压强度随着围压(高压水荷载)的增大而显著增大,在3MPa、5MPa条件下最大可分别增加16.2%和25.5%,并且随着混凝土强度等级的提高,增强效果有减弱趋势；在不密封条件下(高压水荷载直接作用下),混凝土抗压强度增加效果减弱,较密封条件下的强度值下降。
在理论方面,分析了在水力劈裂作用下井壁混凝土裂纹的萌生和扩展,研究了混凝土在高压水荷载作用下的破坏机理,从而对井壁混凝土的破坏机理有了更进一步的认识。本文结果可以为高压水荷载下井壁混凝土强度计算提供实验数据。
With the shallow coal resources exhausted, in order to ensure the sustainable development of coal industry, we need to develop the deep coal resources. Currently, some bore's depth has reached 1,000 meters, but the shaft will pass through deep alluvium during the construction of new wells in the Huang-huai region. The deeper the shafts, the higher the water-pressure imposed on the shaft lining, which brings the safety problem. So it is necessary to study the mechanical properties of wall concrete at the high water -pressure.
It points that the high-pressure water load will be directly on the shaft after the frozen wall thawing, by the analysis of the actual stress state of frozen wall of deep alluvium. Thus the concrete mechanical properties should be considered under direct high-pressure water load.
In the experimental research, sealed and unsealed concrete specimens with 100mm×100mm×100mm cube specimens were imposed loads on by the hydraulic loading device in the institute of underground structures of Anhui University of Science and Engineering, by the ways of different water loads with 0,3MPa and 5MPa. In order to analyze the influence of strength grade of concrete on compressive strength of concrete, we respectively use C50, C60 and C70 concrete standard specimens at the confining pressure of 0,3Mpa and 5MPa, the compressive strength of standard concrete specimens are respectively C50, C60 and C70. The results showed that the compressive strength of concrete evidently increased as increasing of confining pressure when the samples are sealed, it respectively increased 27.8%and 57.2% under 3MPa and 5Mpa confining pressure. And the compressive strength were increased less with the increasing of standard strength grade, also when the samples are not sealed.
In theoretical aspect, the initiation and growth of cracking in the wall concrete in the effect of hydraulic fracture was studied the damage mechanism of concrete under the high-pressure water load was also analyzed. Thus we have further understanding of the failure mechanism of wall concrete. The experimental data is good for the calculation of strength of wall concrete in the high-pressure water load.
通过对深厚表土层冻结井壁实际受力状态的分析,指出在冻结壁解冻后,高压水荷载将直接作用在井壁上,因此,在井壁结构分析中应考虑高压水荷载直接作用下混凝土的力学特性。
在试验研究方面,利用安徽理工大学地下工程结构研究所的液压加载装置进行,混凝土试件采用100mm×100mm×100mm的立方体试件,试验中考虑了不同的加载方式(有水和无水作用)和不同的水荷载大小对试件强度的影响。试验的水荷载作用方式分为试件密封和试件不密封两种。水荷载大小分别为0、3MPa和5MPa。为了分析混凝土的强度等级对混凝土抗压强度的影响,分别采用C50、C60、C70的混凝土标准试件在0、3MPa、5MPa围压下,对混凝土的抗压强度进行试验。试验结果表明,在密封条件下(高压水荷载间接作用下),混凝土的抗压强度随着围压(高压水荷载)的增大而显著增大,在3MPa、5MPa条件下最大可分别增加16.2%和25.5%,并且随着混凝土强度等级的提高,增强效果有减弱趋势；在不密封条件下(高压水荷载直接作用下),混凝土抗压强度增加效果减弱,较密封条件下的强度值下降。
在理论方面,分析了在水力劈裂作用下井壁混凝土裂纹的萌生和扩展,研究了混凝土在高压水荷载作用下的破坏机理,从而对井壁混凝土的破坏机理有了更进一步的认识。本文结果可以为高压水荷载下井壁混凝土强度计算提供实验数据。
With the shallow coal resources exhausted, in order to ensure the sustainable development of coal industry, we need to develop the deep coal resources. Currently, some bore's depth has reached 1,000 meters, but the shaft will pass through deep alluvium during the construction of new wells in the Huang-huai region. The deeper the shafts, the higher the water-pressure imposed on the shaft lining, which brings the safety problem. So it is necessary to study the mechanical properties of wall concrete at the high water -pressure.
It points that the high-pressure water load will be directly on the shaft after the frozen wall thawing, by the analysis of the actual stress state of frozen wall of deep alluvium. Thus the concrete mechanical properties should be considered under direct high-pressure water load.
In the experimental research, sealed and unsealed concrete specimens with 100mm×100mm×100mm cube specimens were imposed loads on by the hydraulic loading device in the institute of underground structures of Anhui University of Science and Engineering, by the ways of different water loads with 0,3MPa and 5MPa. In order to analyze the influence of strength grade of concrete on compressive strength of concrete, we respectively use C50, C60 and C70 concrete standard specimens at the confining pressure of 0,3Mpa and 5MPa, the compressive strength of standard concrete specimens are respectively C50, C60 and C70. The results showed that the compressive strength of concrete evidently increased as increasing of confining pressure when the samples are sealed, it respectively increased 27.8%and 57.2% under 3MPa and 5Mpa confining pressure. And the compressive strength were increased less with the increasing of standard strength grade, also when the samples are not sealed.
In theoretical aspect, the initiation and growth of cracking in the wall concrete in the effect of hydraulic fracture was studied the damage mechanism of concrete under the high-pressure water load was also analyzed. Thus we have further understanding of the failure mechanism of wall concrete. The experimental data is good for the calculation of strength of wall concrete in the high-pressure water load.
引文
[1]崔云龙主编.简明建井工程手册.北京：煤炭工业出版社,2003
[2]周兴旺.我国特殊凿井技术的发展与展望[J].煤炭科学技术,2007,35(10)：10-17.
[3]张荣立,何国纬,李铎.采矿工程设计手册[M].北京：煤炭工业出版社,2002.
[4]姚直书,程桦,杨俊杰.深表土中高强钢筋混凝土井壁力学性能的试验研究[J].煤炭学报,2004,29(2)：167-171.
[5]牛学超等.高强混凝土在立井井壁中的应用及展望[J].中国矿业,2004,13(11)：51-55.
[6]姚直书等.特厚表土层冻结井壁C70高强高性能混凝土配制及其应用.煤炭工程.2006.(8)：33-35.
[7]张元豹.深厚表土层井筒破壁注浆的实践[J].煤炭技术,2006,25(5)：871-91.
[8]李庆斌等.真实水荷载对混凝土强度影响的实验研究[J].水利学报,2007,38(7)：786-790.
[9]马芹永等.混凝土结构基本原理.北京.机械工业出版社,2005：19-25.
[10]李孝利等.岩石混凝土类材料单裂纹水力劈裂研究述评.水利水运工程学报,2005,(1)：67-70.
[11]刘全林等.混凝土井壁竖向极限承载能力计算的研究.煤炭学报,1995,20(6)：583-587.
[12]Mehta P K混凝土的结构、性能与材料[M]祝永年等,译。上海.同济大学出版社,1991.
[13]Clark, J. B A hydraulic process for increasing the productivity of wells Tran AIME (1949)186,1
[14]王媛,徐志英,速宝玉.裂隙岩体渗流计算模型综述[J].水科学进展,1995,(4)：276-282
[15]盛金昌.三维裂隙岩体渗流应力耦合数值分析及工程应用[博士学位论文D].南京：河海大学,2000
[16]郑少河,朱维申,王书法.承压水上采煤的固流耦合问题研究[J].岩石力学与工程学报,2000,19(4)：421-424
[17]柴军瑞,仵彦卿.岩体渗流场与应力场耦合分析的多重裂隙网络模型[J].岩石力学与工程学报,2000,19(6)：712-717
[18]郑少河,朱维申.裂隙岩体渗流损伤耦合模型的理论分析[J].岩石力学与工程学报,2003,20(5)：156-159
[19]杨延毅,周维垣.裂隙岩体的渗流——损伤耦合分析模型及其工程应用[J].水利学报,1991,(5)：19-27
[20]速宝玉,詹美礼,王媛.裂隙渗流与应力耦合特性的试验研究[J].岩土工程学报,1997,19(4)：73-77
[21]郑少河,朱维申.裂隙岩体渗流损伤耦合模型的理论分析[J].岩石力学与工程学报,2001,20(2)：156-159
[22]仵彦卿.岩体渗流场与应力场耦合的双重介质模型[J].水文地质工程地质,1998,1,43-46
[23]朱珍德,胡定.裂隙水压力对岩体强度的影响[J].岩土力学,2000,21(1)：64-67
[24]柴军瑞.考虑渗透动水压力时等效连续岩体渗流场与应力场耦合分析的数学模型[J].四川大学学报(工程科学版),2001,33(6)：14-17
[25]杨天鸿,唐春安,朱万成,冯启言.岩石破裂过程渗流与应力耦合分析[J].岩土工程学报,2001,23(4)：489-493
[26]Tsang Y W, Tsang C F. Channel model of flow through fractured media[J]. Water Resources Research,1987,23(3):467-479
[27]仵彦卿,张悼元.岩体水力学导论[M].成都：西南交通大学出版社,1994
[28]高庆.工程断裂力学[M].重庆：重庆大学出版社,1985
[29]Hillerborg A, Mod6er M, Peterson P E. Analysis of crack propagation and crack growth in concrete by means of fracture mechanics and finite elements[J]. Cement and Concrete Research,1976,6:773-782.
[30]Planas J, Elices M, Guinea GV, G mez F, Cend n D, Arbilla I. Generalizations and specializations of cohesive crack models[J]. Engineering Fracture Mechanics,2003, 70:1759-1776
[31]Alfano G, CrisfeldMA. Finite element interface models for the delamination analysis of laminated composites:mechanical and computational issues[J]. International Journal for Numerical Methods in Engineering,2001,50:1701-1736
[32]方修君,金峰,王进廷.用扩展有限元方法模拟混凝土的复合型开裂过程[J].工程力学,2007,24(增1)：46-52
[33]Barton N, Bandis S, Bakhtar K. Strength, deformation and conductivity coupling of rock joints[J]. International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts,1985,22(3):121-140
[34]Barton N, Choubey V. The shear strength of rock joints in theory and practice[J]. Rock Mechanics,1977,10(1-2):1-54
[35]Barton N, De Quadros E F. Joint aperture and roughness in the prediction of flow and groutability of rock masses[J]. International Journal of Rock Mechanics and Mining Sciences, 1997,34(3-4):252. e251-252. e214
[36]方修君,金峰,王进廷.基于扩展有限元法的粘聚裂纹模型[J].清华大学学报(自然科学 版),2007,47(3)：344-347
[37]李多权等.混凝土抗渗性能研究.科技信息,2008年第16卷：169-171.
[38]崔广心.相似理论与模型试验[M].徐州：中国矿业大学出版社.1990年9月
[2]周兴旺.我国特殊凿井技术的发展与展望[J].煤炭科学技术,2007,35(10)：10-17.
[3]张荣立,何国纬,李铎.采矿工程设计手册[M].北京：煤炭工业出版社,2002.
[4]姚直书,程桦,杨俊杰.深表土中高强钢筋混凝土井壁力学性能的试验研究[J].煤炭学报,2004,29(2)：167-171.
[5]牛学超等.高强混凝土在立井井壁中的应用及展望[J].中国矿业,2004,13(11)：51-55.
[6]姚直书等.特厚表土层冻结井壁C70高强高性能混凝土配制及其应用.煤炭工程.2006.(8)：33-35.
[7]张元豹.深厚表土层井筒破壁注浆的实践[J].煤炭技术,2006,25(5)：871-91.
[8]李庆斌等.真实水荷载对混凝土强度影响的实验研究[J].水利学报,2007,38(7)：786-790.
[9]马芹永等.混凝土结构基本原理.北京.机械工业出版社,2005：19-25.
[10]李孝利等.岩石混凝土类材料单裂纹水力劈裂研究述评.水利水运工程学报,2005,(1)：67-70.
[11]刘全林等.混凝土井壁竖向极限承载能力计算的研究.煤炭学报,1995,20(6)：583-587.
[12]Mehta P K混凝土的结构、性能与材料[M]祝永年等,译。上海.同济大学出版社,1991.
[13]Clark, J. B A hydraulic process for increasing the productivity of wells Tran AIME (1949)186,1
[14]王媛,徐志英,速宝玉.裂隙岩体渗流计算模型综述[J].水科学进展,1995,(4)：276-282
[15]盛金昌.三维裂隙岩体渗流应力耦合数值分析及工程应用[博士学位论文D].南京：河海大学,2000
[16]郑少河,朱维申,王书法.承压水上采煤的固流耦合问题研究[J].岩石力学与工程学报,2000,19(4)：421-424
[17]柴军瑞,仵彦卿.岩体渗流场与应力场耦合分析的多重裂隙网络模型[J].岩石力学与工程学报,2000,19(6)：712-717
[18]郑少河,朱维申.裂隙岩体渗流损伤耦合模型的理论分析[J].岩石力学与工程学报,2003,20(5)：156-159
[19]杨延毅,周维垣.裂隙岩体的渗流——损伤耦合分析模型及其工程应用[J].水利学报,1991,(5)：19-27
[20]速宝玉,詹美礼,王媛.裂隙渗流与应力耦合特性的试验研究[J].岩土工程学报,1997,19(4)：73-77
[21]郑少河,朱维申.裂隙岩体渗流损伤耦合模型的理论分析[J].岩石力学与工程学报,2001,20(2)：156-159
[22]仵彦卿.岩体渗流场与应力场耦合的双重介质模型[J].水文地质工程地质,1998,1,43-46
[23]朱珍德,胡定.裂隙水压力对岩体强度的影响[J].岩土力学,2000,21(1)：64-67
[24]柴军瑞.考虑渗透动水压力时等效连续岩体渗流场与应力场耦合分析的数学模型[J].四川大学学报(工程科学版),2001,33(6)：14-17
[25]杨天鸿,唐春安,朱万成,冯启言.岩石破裂过程渗流与应力耦合分析[J].岩土工程学报,2001,23(4)：489-493
[26]Tsang Y W, Tsang C F. Channel model of flow through fractured media[J]. Water Resources Research,1987,23(3):467-479
[27]仵彦卿,张悼元.岩体水力学导论[M].成都：西南交通大学出版社,1994
[28]高庆.工程断裂力学[M].重庆：重庆大学出版社,1985
[29]Hillerborg A, Mod6er M, Peterson P E. Analysis of crack propagation and crack growth in concrete by means of fracture mechanics and finite elements[J]. Cement and Concrete Research,1976,6:773-782.
[30]Planas J, Elices M, Guinea GV, G mez F, Cend n D, Arbilla I. Generalizations and specializations of cohesive crack models[J]. Engineering Fracture Mechanics,2003, 70:1759-1776
[31]Alfano G, CrisfeldMA. Finite element interface models for the delamination analysis of laminated composites:mechanical and computational issues[J]. International Journal for Numerical Methods in Engineering,2001,50:1701-1736
[32]方修君,金峰,王进廷.用扩展有限元方法模拟混凝土的复合型开裂过程[J].工程力学,2007,24(增1)：46-52
[33]Barton N, Bandis S, Bakhtar K. Strength, deformation and conductivity coupling of rock joints[J]. International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts,1985,22(3):121-140
[34]Barton N, Choubey V. The shear strength of rock joints in theory and practice[J]. Rock Mechanics,1977,10(1-2):1-54
[35]Barton N, De Quadros E F. Joint aperture and roughness in the prediction of flow and groutability of rock masses[J]. International Journal of Rock Mechanics and Mining Sciences, 1997,34(3-4):252. e251-252. e214
[36]方修君,金峰,王进廷.基于扩展有限元法的粘聚裂纹模型[J].清华大学学报(自然科学 版),2007,47(3)：344-347
[37]李多权等.混凝土抗渗性能研究.科技信息,2008年第16卷：169-171.
[38]崔广心.相似理论与模型试验[M].徐州：中国矿业大学出版社.1990年9月