Volume 31 Issue 3
Jun.  2025
Turn off MathJax
Article Contents
Article Navigation >  Journal of Geomechanics  > 2025  >  31(3): 444-457
MA J，HE D F，LU G，et al.，2025. The influence of weak layers on thrust structure deformation: A finite element numerical simulation study[J]. Journal of Geomechanics，31（3）：444−457 doi: 10.12090/j.issn.1006-6616.2024126
Citation: MA J，HE D F，LU G，et al.，2025. The influence of weak layers on thrust structure deformation: A finite element numerical simulation study[J]. Journal of Geomechanics，31（3）：444−457 doi: 10.12090/j.issn.1006-6616.2024126
shu

The influence of weak layers on thrust structure deformation: A finite element numerical simulation study

doi: 10.12090/j.issn.1006-6616.2024126
  • 1.

    School of Energy Resources, China University of Geosciences (Beijing), Beijing 100083, China

  • 2.

    Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059, Sichuan, China

Funds:  This research is financially supported by the Key Program of the National Natural Science Foundation of China (Grant No. 42330810).
More Information
  • Received: 2024-11-19
  • Revised: 2025-04-22
  • Accepted: 2025-04-27
    • Available Online: 2025-05-19
  • Published: 2025-06-28
    Abstract
  •   Objective  As ubiquitous critical structural units in sedimentary basins, weak layers are characterized by low shear strength, low Young’s modulus, and pronounced plastic rheological behavior, playing a key role in stress accommodation and strain partitioning during tectonic deformation. Seismic reflection profiles from areas such as Liangcun, Jiaoshiba, and Changning in southeastern Sichuan reveal widespread regional weak layers within sequences overlying deep thrust fault systems.   Methods  To investigate the dynamic control mechanism of weak layers on thrust deformation, a typical bend fault was selected as the pre-existing fault structure, and comparative experiments with/without weak layers were designed. Finite element modeling was employed to conduct numerical simulations under lateral compression. A comparative analysis of the simulation results from the two model sets systematically examines how weak layers control structural deformation during tectonic movement, particularly the influence of weak layer thickness on upper and lower structural deformation.   Results  (1) The weak layer-free model demonstrates that, under lateral compression, the overlying strata undergo thrust-parallel slip and fold deformation along the pre-existing bend fault. The deformation exhibits remarkable coherence among strata, with no observable interlayer slip or stratified differential deformation. Meanwhile, the maximum principal stress field displays characteristic tectonic stress zoning, while plastic strain concentrates on both the forelimb and the backlimb with upward-decreasing intensity. (2) The weak layer-bearing model reveals that, under combined lateral compression and underlying structural uplift, the weak layer experiences plastic flow, manifesting as top-thinning and limb-thickening. This results in stratified deformation patterns bounded by the weak layer. Furthermore, the distribution of maximum principal stress and plastic strain shows distinct stressen–strain decoupling across the weak layer interface.   Conclusion  (1) The weak layer constitutes a critical factor in initiating structural stratification. Under lateral compression conditions, the weak layer undergoes plastic flow accompanied by localized thickening and thinning. It significantly accommodates underlying structural deformation and stress-strain, thereby generating differential deformation across the weak layer interface and producing distinct stress-strain decoupling between the upper and lower structural domains. (2) The thickness of weak layers constitutes a critical parameter controlling deformation styles. Thicker weak layers result in longer wavelengths and gentler limb dips with reduced uplift amplitudes for overlying folds; they also produce shorter wavelengths, steeper limb dips and greater uplift amplitudes for underlying folds, thereby enhancing deformation partitioning. Conversely, thinner weak layers lead to more coherent deformation between the upper and lower structural domains. [ Significance] The research findings regarding the influence of weak layers on thrust structural deformation revealed in this study can provide valuable references for structural deformation analysis and dynamic modeling in regions with similar stratigraphic characteristics, such as the Liangcun area, the Jiaoshiba block, and the Changning region in southeastern Sichuan.

     

    • Full-text Translaiton by iFLYTEK

    The full translation of the current issue may be delayed. If you encounter a 404 page, please try again later.
    FullText(HTML)
  • loading
    • References(87)
  • [1]
    BAO H P, WANG Q P, YAN W, et al., 2023. Sedimentary characteristics and gas accumulation potential of the Ordovician carbonate-evaporite paragenesis system in central and eastern Ordos Basin[J]. Earth Science Frontiers, 30(1): 30-44. (in Chinese with English abstract
    [2]
    CAO H Y, XU Z X, GAO J J, et al., 2024. Genesis and distribution laws of reservoirs of Cambrian Xixiangchi Group in southeastern Sichuan[J]. Fault-Block Oil & Gas Field, 31(1): 50-59. (in Chinese with English abstract
    [3]
    DUAN Y J, LUO H Y, XIE H W, et al., 2021. Salt-related structural characteristics and deformation mechanism of the Zhongqiu-Dongqiu section of the Qiulitag structural belt, Tarim Basin[J]. Natural Gas Geoscience, 32(7): 993-1008. (in Chinese with English abstract
    [4]
    DUAN Y J, HUANG S Y, LUO C M, et al., 2023. Discussion on balance restoration of salt structure deformation and related problems in Kuqa Depression, Tarim Basin[J]. Natural Gas Geoscience, 34(5): 780-793. (in Chinese with English abstract
    [5]
    DUAN Y J, HUANG S Y, LUO C M, et al., 2024. Tectonic deformation characteristics of multi-detachment beds in Kuqa foreland thrust belt, Tarim Basin[J]. Natural Gas Geoscience, 35(9): 1544-1556. (in Chinese with English abstract
    [6]
    ERICKSON S G, STRAYER L M, SUPPE J, 2005. Numerical modeling of hinge-zone migration in fault-bend folds(Article)[J]. AAPG Memoir, (82): 438-452.
    [7]
    GU Z D, YIN J F, YUAN M, et al., 2015. Accumulation conditions and exploration directions of natural gas in deep subsalt Sinian-Cambrian System in the eastern Sichuan Basin, SW China[J]. Petroleum Exploration and Development, 42(2): 137-149. (in Chinese with English abstract
    [8]
    HE D F, LI D S, ZHANG G W, et al., 2011. Formation and evolution of multi-cycle superposed Sichuan basin, China[J]. Chinese Journal of Geology, 46(3): 589-606. (in Chinese with English abstract
    [9]
    HE D F, LI D S, HE J Y, et al., 2013. Comparison in petroleum geology between Kuqa depression and Southwest depression in Tarim Basin and its exploration significance[J]. Acta Petrolei Sinica, 34(2): 201-218. (in Chinese with English abstract
    [10]
    HE D F, SHAO D B, KAI B Z, et al., 2019a. Structural style and trap distribution in Majiatan area on the western margin of ordos basin[J]. Acta Geoscientica Sinica, 40(1): 219-235. (in Chinese with English abstract
    [11]
    HE D F, LU R Q, HUANG H Y, et al., 2019b. Tectonic and geological background of the earthquake hazards in Changning shale gas development zone, Sichuan Basin, SW China[J]. Petroleum Exploration and Development, 46(5): 993-1006. (in Chinese with English abstract
    [12]
    HE D F, 2022. Multi-cycle superimposed sedimentary basins in China: Formation, evolution, geologic framework and hydro-carbon occurrence[J]. Earth Science Frontiers, 29(6): 24-59. (in Chinese with English abstract
    [13]
    HU C B, ZHOU Y J, CAI Y E, 2009. A new finite element model in studying earthquake triggering and continuous evolution of stress field[J]. Science in China Series D: Earth Sciences, 52(7): 994-1004. doi: 10.1007/s11430-009-0082-3
    [14]
    HUDEC M R, JACKSON M P A, 2006. Advance of allochthonous salt sheets in passive margins and orogens[J]. AAPG Bulletin, 90(10): 1535-1564. doi: 10.1306/05080605143
    [15]
    JIA X L, 2016. Structural Geometry and Kinematics of Southeastern Sichuan: Tectonic Relationships with the Western Xuefeng Mountain[D]. China University of Geosciences (Beijing). (in Chinese with English abstract
    [16]
    JIANG Q C, LI J Z, WANG Z C, et al., 2022. Quantitative thickness prediction of Cambrian gypsum-salt rocks in eastern Sichuan Basin and its petroleum significance[J]. Natural Gas Industry, 42(5): 34-46. (in Chinese with English abstract
    [17]
    KHALIFEH-SOLTANI A, ALAVI S A, GHASSEMI M R, et al., 2023. Stress and strain evolution in fault-related folds: insights from 2D geomechanical modelling[J]. Frontiers in Earth Science, 11: 1249446. doi: 10.3389/feart.2023.1249446
    [18]
    LI B L, SUN Y, ZHU W B, et al., 2001. Study on the layer-slip parameter systems in the eastern Sichuan[J]. Journal of Southwest Petroleum Institute, 23(1): 29-33. (in Chinese with English abstract
    [19]
    LI C S, YIN H W, WU Z Y, et al., 2021. Effects of salt thickness on the structural deformation of foreland fold-and-thrust belt in the Kuqa Depression, Tarim Basin: insights from discrete element models[J]. Frontiers in Earth Science, 9: 655173. doi: 10.3389/feart.2021.655173
    [20]
    LIN L B, HAO Q, YU Y, et al., 2014. Development characteristics and sealing effectiveness of Lower Cambrian gypsum rock in Sichuan Basin[J]. Acta Petrologica Sinica, 30(3): 718-726. (in Chinese with English abstract
    [21]
    MA J, HE D F, ZHANG W K, et al., 2024. Numerical simulation of present-day stress field on the top surface of Ordovician Wufeng Formation shale in the Shilongxia anticline area, southeast Sichuan, China[J]. Chinese Journal of Geology, 59(3): 792-803. (in Chinese with English abstract
    [22]
    PANG Y Z, CHENG K Q, ZHANG P X, et al., 2025. Simulation of paleotectonic stress field of Silurian Longmaxi shale reservoirs in Wulong area of southeastern Chongqing[J]. Acta Seismologica Sinica, 47(1): 73-92. (in Chinese with English abstract
    [23]
    PLOTEK B, GUZMÁN C, CRISTALLINI E, et al., 2021. Analysis of fault bend folding kinematic models and comparison with an analog experiment[J]. Journal of Structural Geology, 146: 104316. doi: 10.1016/j.jsg.2021.104316
    [24]
    SUPPE J, 1983. Geometry and kinematics of fault-bend folding[J]. American Journal of Science, 283(7): 684-721. doi: 10.2475/ajs.283.7.684
    [25]
    TONG H M, ZHANG H X, HOU Q L, et al., 2024. Generalized fracturing activation criteria[J]. Journal of Geomechanics, 30(1): 3-14. (in Chinese with English abstract
    [26]
    WANG L, WU Z Y, YIN H W, et al., 2021. Compressional salt structures of salt-bearing sedimentary basins and its significance to hydrocarbon accumulation[J]. Bulletin of Geological Science and Technology, 40(5): 136-150. (in Chinese with English abstract
    [27]
    WANYAN Q Q, SHEN X M, GOU Y X, et al., 2016. The analysis of the mechanical properties of typical salt rock[J]. Journal of Southwest Petroleum University (Science & Technology Edition), 38(1): 60-67. (in Chinese with English abstract
    [28]
    WEI J, HOU G T, ZHANG B, et al., 2014. Insights into the damage zones in fault-bend folds from geomechanical models and field data[J]. Tectonophysics, 610: 182-194. doi: 10.1016/j.tecto.2013.11.022
    [29]
    WU Z Y, YANG X L, YIN H W, et al., 2023. Characteristics and influencing factors of salt structure evolution in Awate transfer zone, western Kuqa depression[J]. Earth Science, 48(4): 1271-1287. (in Chinese with English abstract
    [30]
    XIE J T, FU X P, QIN Q R, et al., 2021. Prediction of fracture distribution and evaluation of shale gas preservation conditions in Longmaxi Formation in Dongxi area[J]. Coal Geology & Exploration, 49(6): 35-45. (in Chinese with English abstract
    [31]
    XU B T, YAN C H, CHEN H Y, et al., 2008. Experimental study of mechanical property of weak intercalated layers in slope rock mass[J]. Rock and Soil Mechanics, 29(11): 3077-3081. (in Chinese with English abstract
    [32]
    XU K, DAI J S, FENG J W, et al., 2015. Application of ANSYS in discussing influence of weak interbed on rock fracture[J]. Fault-Block Oil & Gas Field, 22(6): 735-739. (in Chinese with English abstract
    [33]
    XU W L, LI J Z, LIU X S, et al., 2021. Accumulation conditions and exploration directions of Ordovician lower assemblage natural gas, Ordos Basin, NW China[J]. Petroleum Exploration and Development, 48(3): 549-561. (in Chinese with English abstract
    [34]
    YANG K J, QI J F, LIU A R, et al., 2022. Characteristics of basement faults in the middle section of Kuqa Depression and their influence on salt tectonic deformation[J]. Chinese Journal of Geology, 57(4): 991-1008. (in Chinese with English abstract
    [35]
    YANG X L, 2023. Physical Modeling on the deformation evolution of compressional salt structures in the western Kuqa depression[D]. Fuzhou: East China University of Technology. (in Chinese with English abstract
    [36]
    YANG X P, CHEN J, LI A, et al., 2024. Structural deformation characteristics of active anticline and their implications for seismogeological disaster effect under compression setting in the Late Cenozoic[J]. Journal of Geomechanics, 30(2): 225-241. (in Chinese with English abstract
    [37]
    YIN L, LUO G, 2018. Crustal deformation across the Longmen Shan fault zone from finite element simulation of seismic cycles[J]. Chinese Journal of Geophysics, 61(4): 1238-1257. (in Chinese with English abstract
    [38]
    YUAN J, ZHU S B, 2014. FEM simulation of the dynamic processes of fault spontaneous rupture[J]. Chinese Journal of Geophysics, 57(1): 138-156. (in Chinese with English abstract
    [39]
    ZHANG B L, ZHU G, JIANG D Z, et al., 2009. Numerical modeling and formation mechanism of the eastern Sichuan Jura-type folds[J]. Geological Review, 55(5): 701-711. (in Chinese with English abstract
    [40]
    ZHANG X L, LIU Z J, CHEN C, et al., 2023. Differences in preservation conditions of deep shale gas in high-steep complex tectonic belt: taking Qijiang high-steep complex tectonic belt in southeast Sichuan as an example[J]. Petroleum Geology & Experiment, 45(6): 1121-1131. (in Chinese with English abstract
    [41]
    ZHANG Z Q, LI N, CHEN F F, et al., 2010. A practical method to simulate thickness of weak interbed and its application[J]. Chinese Journal of Rock Mechanics and Engineering, 29(S1): 2637-2644. (in Chinese with English abstract
    [42]
    ZHAO L, LIAO Z T, XU X H, et al. , 2019. Physical modeling of thrusting structure zonation in front of an intracontinental orogen[J]. Petroleum Geology & Experiment, 41(6): 871-878, 884. (in Chinese with English abstract
    [43]
    ZHAO S X, XU W Q, YANG X F, et al., 2023. Structural characteristics and deformation mechanisms of multiple-detachments in Luzhou area, southeastern Sichuan Basin[J]. Geological Journal of China Universities, 29(5): 726-734. (in Chinese with English abstract
    [44]
    ZHAO W Z, HU S Y, WANG Z C, et al., 2003. Key role of basement fault control on oil accumulation of Yanchang Formation, Upper Triassic, Ordos Basin[J]. Petroleum Exploration and Development, 30(5): 1-5. (in Chinese with English abstract
    [45]
    ZHONG C, QIN Q R, ZHOU J L, et al., 2018. Study on fault sealing of organic-rich shale by present stress: a case study of Longmaxi formation in Dingshan area, southeast Sichuan[J]. Journal of Geomechanics, 24(4): 452-464. (in Chinese with English abstract
    [46]
    ZHOU S H, ZHANG H, SUN Y Q, et al., 2023. Numerical simulation of tectonic stress and strain rate fields in the northeastern margin of the Tibetan Plateau in association with major fault zones[J]. Science China Earth Sciences, 66(10): 2353-2367. doi: 10.1007/s11430-021-1177-9
    [47]
    ZU K W, ZENG L B, ZHAO X Y, et al., 2014. Discussion on development models of the shearing fractures in fault bend folds[J]. Journal of Geomechanics, 20(1): 16-24. (in Chinese with English abstract
    [48]
    包洪平,王前平,闫伟,等,2023. 鄂尔多斯盆地中东部奥陶系碳酸盐岩-膏盐岩体系沉积特征与天然气成藏潜力[J]. 地学前缘,30(1):30-44.
    [49]
    曹环宇,徐祖新,高俊杰,等,2024. 川东南地区寒武系洗象池群储层成因及分布规律[J]. 断块油气田,31(1):50-59.
    [50]
    段云江,罗浩渝,谢会文,等,2021. 塔里木盆地库车坳陷秋里塔格构造带中秋—东秋段盐相关构造特征及变形机理[J]. 天然气地球科学,32(7):993-1008.
    [51]
    段云江,黄少英,罗彩明,等,2023. 塔里木盆地库车坳陷盐构造变形平衡恢复及相关问题讨论[J]. 天然气地球科学,34(5):780-793. doi: 10.11764/j.issn.1672-1926.2022.11.006
    [52]
    段云江,黄少英,罗彩明,等,2024. 塔里木盆地库车前陆冲断带多滑脱层构造变形特征[J]. 天然气地球科学,35(9):1544-1556. doi: 10.11764/j.issn.1672-1926.2024.03.009
    [53]
    谷志东,殷积峰,袁苗,等,2015. 四川盆地东部深层盐下震旦系—寒武系天然气成藏条件与勘探方向[J]. 石油勘探与开发,42(2):137-149. doi: 10.11698/PED.2015.02.02
    [54]
    何登发,李德生,张国伟,等,2011. 四川多旋回叠合盆地的形成与演化[J]. 地质科学,46(3):589-606.
    [55]
    何登发,李德生,何金有,等,2013. 塔里木盆地库车坳陷和西南坳陷油气地质特征类比及勘探启示[J]. 石油学报,34(2):201-218.
    [56]
    何登发,邵东波,开百泽,等,2019a. 鄂尔多斯盆地西缘马家滩地区的构造样式与圈闭分布规律[J]. 地球学报,40(1):219-235.
    [57]
    何登发,鲁人齐,黄涵宇,等,2019b. 长宁页岩气开发区地震的构造地质背景[J]. 石油勘探与开发,46(5):993-1006.
    [58]
    何登发,2022. 中国多旋回叠合沉积盆地的形成演化、地质结构与油气分布规律[J]. 地学前缘,29(6):24-59.
    [59]
    胡才博,周一杰,蔡永恩,2009. 如何用有限元新模型研究地震触发和应力场连续演化[J]. 中国科学 D辑:地球科学,39(5):546-555.
    [60]
    贾小乐,2016. 川东南构造几何学与运动学特征及其与雪峰山西段的构造关系探讨[D]. 中国地质大学(北京).
    [61]
    江青春,李建忠,汪泽成,等,2022. 四川盆地东部地区寒武系膏盐岩厚度定量预测及其油气地质意义[J]. 天然气工业,42(5):34-46.
    [62]
    李本亮,孙岩,朱文斌,等,2001. 川东地区层滑参数系统研究[J]. 西南石油学院学报,23(1):29-33.
    [63]
    林良彪,郝强,余瑜,等,2014. 四川盆地下寒武统膏盐岩发育特征与封盖有效性分析[J]. 岩石学报,30(3):718-726.
    [64]
    马佳,何登发,张伟康,等,2024. 川东南石龙峡背斜区奥陶系五峰组页岩顶面现今应力场数值模拟研究[J]. 地质科学,59(3):792-803.
    [65]
    庞一桢,陈孔全,张培先,等,2025. 渝东南武隆地区志留系龙马溪组页岩储层的古构造应力场模拟[J]. 地震学报,47(1):73-92. doi: 10.11939/jass.20230137
    [66]
    童亨茂,张宏祥,侯泉林,等,2024. 广义破裂活动准则[J]. 地质力学学报,30(1):3-14. doi: 10.12090/j.issn.1006-6616.2023180
    [67]
    完颜祺琪,沈雪明,垢艳侠,等,2016. 典型盐岩力学特性分析[J]. 西南石油大学学报(自然科学版),38(1):60-67.
    [68]
    王莉,吴珍云,尹宏伟,等,2021. 含盐沉积盆地挤压盐构造及其对油气成藏的意义[J]. 地质科技通报,40(5):136-150.
    [69]
    吴珍云,杨秀磊,尹宏伟,等,2023. 库车坳陷西段阿瓦特构造转换带盐构造演化特征及影响因素[J]. 地球科学,48(4):1271-1287.
    [70]
    谢佳彤,付小平,秦启荣,等,2021. 川东南东溪地区龙马溪组裂缝分布预测及页岩气保存条件评价[J]. 煤田地质与勘探,49(6):35-45.
    [71]
    许宝田,阎长虹,陈汉永,等,2008. 边坡岩体软弱夹层力学特性试验研究[J]. 岩土力学,29(11):3077-3081. doi: 10.3969/j.issn.1000-7598.2008.11.033
    [72]
    徐珂,戴俊生,冯建伟,等,2015. 运用ANSYS法探讨软弱夹层对岩体破裂的影响[J]. 断块油气田,22(6):735-739.
    [73]
    徐旺林,李建忠,刘新社,等,2021. 鄂尔多斯盆地奥陶系下组合天然气成藏条件与勘探方向[J]. 石油勘探与开发,48(3):549-561. doi: 10.11698/PED.2021.03.10
    [74]
    杨克基,漆家福,刘傲然,等,2022. 库车坳陷中段基底断裂特征及其对盐构造变形的影响[J]. 地质科学,57(4):991-1008.
    [75]
    杨晓平,陈杰,李安,等,2024. 新生代晚期挤压作用下活动背斜区的构造变形特征及其地震地质灾害效应[J]. 地质力学学报,30(2):225-241.
    [76]
    杨秀磊,2023. 库车坳陷西段挤压盐构造变形演化过程的物理模拟实验研究[D]. 抚州:东华理工大学.
    [77]
    尹力,罗纲,2018. 有限元数值模拟龙门山断裂带地震循环的地壳变形演化[J]. 地球物理学报,61(4):1238-1257. doi: 10.6038/cjg2018L0248
    [78]
    袁杰,朱守彪,2014. 断层自发破裂动力过程的有限单元法模拟[J]. 地球物理学报,57(1):138-156. doi: 10.6038/cjg20140113
    [79]
    张必龙,朱光,JIANG D Z,等,2009. 川东“侏罗山式”褶皱的数值模拟及成因探讨[J]. 地质论评,55(5):701-711. doi: 10.3321/j.issn:0371-5736.2009.05.012
    [80]
    张旭亮,刘珠江,陈超,等,2023. 高陡复杂构造带深层页岩气保存条件差异性分析:以川东南綦江高陡复杂构造带为例[J]. 石油实验地质,45(6):1121-1131. doi: 10.11781/sysydz2023061121
    [81]
    张志强,李宁,陈方方,等,2010. 软弱夹层厚度模拟实用方法及其应用[J]. 岩石力学与工程学报,29(S1):2637-2644.
    [82]
    赵利,廖宗廷,徐旭辉,等,2019. 陆内山前冲断结构分带的构造物理模拟实验[J]. 石油实验地质,41(6):871-878,884. doi: 10.11781/sysydz201906871
    [83]
    赵圣贤,徐雯峤,杨学锋,等,2023. 川东南泸州地区多滑脱层构造特征及变形机制[J]. 高校地质学报,29(5):726-734.
    [84]
    赵文智,胡素云,汪泽成,等,2003. 鄂尔多斯盆地基底断裂在上三叠统延长组石油聚集中的控制作用[J]. 石油勘探与开发,30(5):1-5. doi: 10.3321/j.issn:1000-0747.2003.05.001
    [85]
    钟城,秦启荣,周吉羚,等,2018. 现今地应力对富有机质页岩断层封闭性的研究:以川东南丁山地区龙马溪组为例[J]. 地质力学学报,24(4):452-464.
    [86]
    周书红,张怀,孙云强,等,2023. 青藏高原东北缘与主要断裂带相关的构造应力率和应变率场的数值模拟[J]. 中国科学:地球科学,53(10):2392-2406.
    [87]
    祖克威,曾联波,赵向原,等,2014. 断层转折褶皱剪切裂缝发育模式探讨[J]. 地质力学学报,20(1):16-24.
    • Relative Articles
    • Supplements(0)
    • Cited By
  • 加载中

Catalog

    Figures(9)  / Tables(4)

    Get Citation
    PDF
    XML

    Article Metrics

    Article views (439) PDF downloads(49) Cited by()
    Proportional views
    Related

    Website Copyright © Journal of Geomechanics  京ICP备18031784号  Total visits：

    Supported by: Beijing Renhe Information Technology Co., Ltd.    

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return