Numerical simulation for migration rule of fault gas radon in different overburden
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摘要: 断层气氡浓度是探测断层位置与断层活动性的一种有效手段. 该文基于Abdoh和Pilkington提出的氡迁移二维偏微分方程与相应的边界条件, 建立内部含裂隙、 裂隙系-断层带和非均质等3种覆盖层物理模型, 在Matlab平台上运用偏微分工具箱(pdetool)与非线性求解函数(pdenonlin), 对模型求解以及模拟覆盖层中氡迁移. 通过对3种模型的模拟结果分析, 分别解释了地表氡异常点与断层带位置不同步现象, 覆盖层厚度对氡浓度曲线形状的影响, 以及土壤结构性质对氡异常强度和异常形态的影响.Abstract: Measuring the concentration of the fault gas radon is an effective method to explore fault location and fault activity. Based on Abdoh and Pilkington’s two-dimensional partial differential equation and corresponding boundary conditions of radon migration, we establish three physical models of the overburden: internal fracture, fracture-fault and heterogeneous overburden. Then we solve these models and simulate radon migration in the overburden using partial differential toolbox (pdetool) and non-linear solution function (pdenonlin) on the Matlab platform. Finally, we analyze the simulation results of the three models, which explain the phenomena that the radon abnormal points on overburden surface are out of sync with the fault location. It is also interpreted the effect of thickness of overburden on the shape of the radon concentration curve, and impactions of the soil structural properties on the radon anomaly intensities and shapes.
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Keywords:
- fault gas /
- radon /
- migration rule /
- numerical simulation /
- physical model /
- Matlab
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图 1 含氡源断层带上方覆盖层的物理模型(引自Abdoh, Pilkington, 1989)
Figure 1. The physical model of fault zone that contains a radon source and is covered by overburden (after Abdoh, Pilkington, 1989)
表 1 氡气在不同土壤性质下的有效扩散系数(D*)、 扩散系数(D)和孔隙度(e)三者之间的关系(据吴慧山等, 1995)
Table 1 The relationship among effective diffusion coefficient (D*), diffusion coefficient (D) and porosity (e) of radon in different types of soils (Wu et al, 1995)
土壤性质 孔隙度e 扩散系数D/(10-2 cm2·s-1) 有效扩散系数D*/(cm2·s-1) 砂子 40% 4.5—7.0 0.11—0.175 疏松沉积物 20% 2.0—2.5 0.1—0.125 白黏土 59.3% 1.53 0.023 砂质黏土 10.8% 1.09 0.1 -
陈万春. 1996. 地震断层气监测的现状与展望[J]. 四川地震, (2): 56-60 Chen W C. 1996. The presents and prospects about the monitoring of seismic fault product gas[J]. Earthquake Research in Sichuan, (2): 56-60 (in Chinese)
国家地震局科技监测司. 1985. 地震地下水手册[M]. 北京: 地震出版社: 621-623 Department of Science and Technology Monitoring, China Earthquake Administration. 1985. The Seismic Groundwater Handbook[M]. Beijing: Seismological Press: 621-623 (in Chinese)
贾文懿, 方方, 周蓉生, 马英杰, 邱元德, 候新生, 吴允平, 祖秀兰, 王小琴. 2000. 氡及其子体运移规律与机理研究[J]. 核技术, 23 (3): 169-175 Jia W Y, Fang F, Zhou R S, Ma Y J, Qiu Y D, Hou X S, Wu Y P, Zu X L, Wang X Q. 2000. Study on the migration rule and mechanism of radon and its daughters[J]. Nuclear Techniques, 23 (3): 169-175 (in Chinese)
刘菁华, 王祝文, 田钢, 王晓丽. 2007. 均匀覆盖层中氡迁移的数值模拟[J]. 地球物理学报, 50 (3): 921-925 Liu J H, Wang Z W, Tian G, Wang X L. 2007. Numerical simulation for radon migration in the homogeneous overburden[J]. Chinese J Geophys, 50 (3): 921-925 (in Chinese)
汪成民, 李宣瑚, 魏柏林. 1991. 断层气测量在地震科学中的应用[M]. 北京: 地震出版社: 58-60, 84-86 吴华平, 郭良田, 常郁, 陈少坚. 2009. 氡断层气测量在佛山西淋岗活断层探测中的应用研究[J]. 华南地震, 29 (4): 108-113 Wu H P, Guo L T, Chang Y, Chen S J. 2009. An experimental study on active fault radon gases measurement in Foshan Xilingang fault[J]. South China Journal of Seismology, 29 (4): 108-113 (in Chinese)
吴慧山, 林玉飞, 白云生, 常桂兰. 1995. 氡测量方法与应用[M]. 北京: 原子能出版社: 142-143 Wu H S, Lin Y F, Bai Y S, Chang G L. 1995. Methods and Applications of Radon Measurement[M]. Beijing: Atomic Energy Press: 142-143 (in Chinese)
张慧, 张新基, 苏鹤军, 刘旭宙. 2005. 金城关活动断裂带土壤气氡、 汞地球化学特征[J]. 西北地震学报, 27 (2): 150-153 Zhang H, Zhang X J, Su H J, Liu X Z. 2005. The geochemical features of radon and mercury on Lanzhou Jinchengguan active fault[J]. Northwestern Seismological Journal, 27 (2): 150-153 (in Chinese)
张慧, 张新基, 苏鹤军, 刘旭宙. 2010. 兰州市活动断层土壤气汞、 氡地球化学特征场地试验[J]. 西北地震学报, 32 (3): 273-278 Zhang H, Zhang X J, Su H J, Liu X Z. 2010. Field test on the geochemical features of radon and mercury from soil gas on the active faults in Lanzhou[J]. Northwestern Seismological Journal, 32 (3): 273-278 (in Chinese)
张新基, 张慧, 苏鹤军, 刘旭宙. 2005. 刘家堡活动断层土壤气氡汞地球化学特征[J]. 地震, 25 (4): 87-92. Zhang X J, Zhang H, Su H J, Liu X Z. 2005. Geochemical feature of radon and mercury across Liujiapu active fault[J]. Earthquake, 25 (4): 87-92 (in Chinese)
Султанходжаев А Н, Тыминский В Г, Спиридонов А И(著). 1979. 蔡祖煌, 石慧馨(译). 1983. 放射性气体在研究地质过程中的应用[M]. 北京: 地震出版社: 1-3 Султанходжаев А Н, Тыминский В Г, Спиридонов А И. 1979. The Application of Radioactive Gas in the Study of Geological Process[M]. Beijing: Seismological Press: 1-3 (in Chinese)
Abdoh A, Pilkington M. 1989. Radon emanation studies of the Ile Bizard fault, Montreal[J]. Geoexploration, 25 (4): 341-354
Fleischer R L, Hart H R, Mogro-Campero A.1980. Radon emanation over an ore body: Search for long-distance transport of radon[J]. Nuclear Instruments and Methods, 173 (1): 169-181
Flügge S, Zimens K E. 1939. Die bestimmung von korngröβen und von diffusionskonstanten aus dem emaniervermögen (Die theorie der emardermethode)[J]. Z Phys Chem B, 42 : 179-220
Ioannides K, Papachristodoulou C, Stamoulis K, Karamanis D, Pavlides S, Chatzipetros A, Karakala E. 2003. Soil gas radon: A tool for exploring active fault zones[J]. Appl Radiat Isot, 59 (2/3): 205-213
Iskandar D, Iida T, Yamazawa H, Moriizumi J, Koarashi J, Yamasoto K, Yamasaki K, Shimo M, Tsujimoto T, Ishikawa S, Fukuda M, Kojima H. 2005. The transport mechanisms of 222Rn in soil at Tateishias as an anomaly spot in Japan[J]. Appl Radiat Isot, 63 (2): 401-408
Kohl T, Medici F, Rybach L. 1994. Numerical simulation of radon transport from subsurface to buildings[J]. J Appl Geophys, 31 (1/2/3/4): 145-152
Malmquist L, Isaksson M, Kristiansson K. 1989. Radon migration through soil and bedrock[J]. Geoexploration, 26 (2): 135-144
Morin J P, Seidel J L, Monnin M. 1993. A tri-dimensional model for radon transport in a porous medium[J]. Nucl Tracks Radiat, 22 (1/2/3/4): 415-418
Semkow T M, Parekh P P. 1990. The role of radium distribution and porosity in radon emanation from solids[J]. Geophy Res Lett, 17 (6): 837-840
Swakon J, Kozak K, Paszkowski M, Gradzin′ ski R, Loskiewicz J, Mazur J, Janik M, Bogacz J, Horwacik T, Olko P. 2004. Radon concentration in soil gas around local disjunctive tectonic zones in the Krakow area [J]. J Environ Radioactiv, 78 (2): 137-149
Voltattorni N, Lombardi S. 2010. Soil gas geochemistry: Significance and application in geological prospectings[J]. Natural Gas, 9 : 183-205
Walia V, Yang T F, Hong W L, Li S J, Fu C C, Wen K L, Chen C H. 2009. Geochemical variation of soil-gas composition for fault trace and earthquake precursory studies along the Hsincheng fault in NW Taiwan[J]. Appl Radiat Isot, 67 (10): 1855-1863
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