بررسی رابطۀ سختی سنگ و تولید واریزه به روش سلبی اصلاح‌شده (مطالعۀ موردی: ماسه‌سنگ آغاجاری)

نوع مقاله : مقاله کامل

نویسندگان

1 استادیار دانشکدة جغرافیا، دانشگاه تهران

2 دانشجوی دکتری دانشکدة جغرافیا، دانشگاه تهران

چکیده

در این پژوهش، با توجه به اهمیت لندفرم‌های واریزه‌ای، به وسیلة روش سلبی، به برآورد مقدار سختی سنگ‏ها در سازند آغاجاری و رابطة آن با تولید واریزه‏ پرداخته شد. در روش سلبی شش پارامترـ سختی چکش اشمیت، جهت درزه نسبت به شیب دامنه، درجة هوازدگی، عرض، فاصله، و پیوستگی درزه‌ـ در مقاومت سنگ دخیل است و هر پارامتر به پنج دسته تقسیم می‌شود: بسیار نامقاوم، نامقاوم، مقاومت میانه، مقاوم، و بسیار مقاوم. در روش بومی‌سازی‌شده، فاکتور تخلخل نیز اضافه ‌شد. نمونه‌ها از چهار خط نمونه‌برداری (هر خط شامل هشت نمونة A تا H است) شد؛ در مجموع، ۳۲ نمونه برداشت شد. در این پژوهش، از چکش اشمیت مدل N و استاندارد ISRM استفاده شد. برای ترسیم لندفرم‏های واریزه‏ای از نقشة ۲۵۰۰۰/۱ و نرم‌افزار Arc GIS و Surfer استفاده شد. نتایج این پژوهش حاکی است از رابطة قوی و مستقیم بین واریزه‏های سنگی با پارامترهای سختی چکش اشمیت، هوازدگی، و پیوستگی درزه و رابطة متوسط با پیوستگی درزه و تخلخل و رابطة ضعیف با فاصلة درزه‏ها و فقدان رابطه با پهنای درزه‏ها. لایة A (قدیمی‌ترین لایه) دارای کمترین مقاومت و سختی در سازند آغاجاری است.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Relationship between rock hardness and debris generation by modified Selby method (Case study: Agha - Jari Sandstone)

نویسندگان [English]

  • Shirin Mohammadkhan 1
  • Amir Ahmadi 2
1 Assistant Professor of geomorphology, Faculty of Geography, University of Tehran, Iran
2 PhD student in geomorphology, University of Tehran, Iran
چکیده [English]

Introduction
Debris and rocky hillsides are one of the important and typical landforms in arid and semi-arid regions. In this study, the relation between the hardness of Aghajari sandstone with producing the debris has been surveyed by Selby Method. The sandstone rocks display obviously landscape features. Debris is one of these landscapes. Rock fall and rock topple can create these landscapes. Debris is characteristic of arid and semi-arid region. Geology and climate are the main mechanisms for generation of the debris. Weathering, gravity, earthquake, joints and fluctuation of temperature are other agents. Selby (1980) method was used in order to determine the effective factors on production of the debris. To determine resistance of rocks, Schmidt Rebound Hardness (SRH) is so practical. So far in geomorphology and geology, more than half a century, the SRH was used in researches. In addition to the Selby method, porosity was used to determine  rock hardness in this paper. The aim of this study is to study the effects of rock hardness characteristics on generation of debris, based on modified Selby method, on Agha - Jari sandstone in southwest  Iran (Masjed - Soleyman).
 
Material and methods
In this study, in sampling  and estimation of SRH, the samples were taken along eight layers which are named from A to H. The samples A1 to A4 were taken from the oldest layer and samples H1 to H4 from the youngest. Because the thicknesses of layers vary from place to place, the sampling interval changes from 50 to 150 meters. Geomorphic map was prepared by freehand software and using 1:25,000 topographic maps of Iranian Survey Organization. Geological data, such as lithology and contacts of the Aghajari sandstone layers, were drawn by using 1:100,000 geological maps of Geological Survey of Iran. Also some factors of Selby method such as properties of joints including width, spacing, lateral or vertical continuity, and orientation with respect to the slopes as well as weathering of the rocks was estimated on the field. Thin section samples were prepared from fresh rock samples. After preparing thin sections, porosity was determined via point counting by 400 points in each sample.
 
Results and discussion
For understanding the effects of each Selby factor with debris, we compared all factors to measure the amount of debris on the layers. The samples B, C, D and F have the most debris in all layers and A layer don’t have any debris. The results showed that there is direct relationship by increasing between SRH and amount of debris with a high correlation (89%). The factors showed the correlations; Width of the joints: non correlation, the spacing of joints: low correlation (21%), weathering: high correlation (87%), lateral or vertical continuity of the joints: high correlation (83%), Orientation of joints with respect to the slopes: almost high correlation (63%) and porosity: mid correlation (56%).
 
Conclusion
The results of this paper showed high relationship between debris and SRH, weathering and lateral or vertical continuity of the joints and also low relationship between the spacing of joints and non-relationship between widths of the joints. Porosity and Orientation of joints with respect to the slopes have mid relationship with debris. The A layer (the oldest layer) is the weakest layer. The layers B, C, D, E, G, and F are resistances and H layer (the youngest) is mid hardness.
 

کلیدواژه‌ها [English]

  • Agha - Jari sandstone
  • Debris
  • Selby method
  • SRH
  • Rock hardness

مراجع

آقانباتی، س.ع. (۱۳۸۳). زمین‌شناسیایران، انتشارات سازمان زمین‌شناسی و اکتشافات کشور، صفحات ۴۵۶.
احمدی، ا. (۱۳۹۱). مکانیسم شکل‏زای کواترنری بر روی ماسه‌سنگ آغاجاری در شمال باختری مسجد سلیمان، پایان‌نامة کارشناسی ارشد دانشکدة جغرافیا، دانشگاه تهران، رشتة ژئومورفولوژی.
زمان‌زاده، س. م؛ احمدی، ا. و احمدی، ع.ح. (۱۳۹۳). بررسی اثر کربنات کلسیم و تخلخل در ایجاد دامنه‌های سنگی در سازند آغاجاری، نخستینهمایشعلومجغرافیاییایران، دانشگاه تهران، مؤسسة جغرافیا.
تهرانی، خسرو. 1384. زمین شناسی ایران، انتشارات دانشگاه تهران.
مطیعی، ﻫ. (۱۳۷۲). زمین‌شناسیایران: چینه‌شناسیزاگرس، انتشارات سازمان زمین‌شناسی کشور.
Aghanabati, S.A. (2004). Iran Geology, Geological Survey & Mineral Explorations of Iran (GSI) press, PP 456.
Ahmadi, A.; Moghimi, E.; Zamanzadeh, S.M. and Motamed, R. (2015). The Effect of Sandstone Composition on Distribution of Tafoni Landforms in the Aghajari Sandstone, Northwest of Masjed Soleyman, Iran, Hindawi Publishing Corporation Advances in Geology, Volume (2015). Article ID 862714, 10 pages.
Ahmadi, A. (2012). Mechanism of Quaternary morphogenesis on the sandstone Aghajari formation northwest MasjedSoleyman, Msc Thesis, Geography College, university of Tehtran.
Alavi, M. (1994). Tectonics of the Zagros organic belt of Iran: new data and interpretations, Tectonophysics, 229: 211-238.
Alejanoa, L.R.; Carranza, T.C.; Giani, G.P. and Arzúa, J. (2015). Study of the stability against toppling of rock blocks with rounded edges based on analytical and experimental approaches, EngineeringGeology, 195: 172-184.
Arribas, M.E.; Rodríguez-López, J.P.; Meléndez, N.; Soria, A.R. and Boer, P. (2012). Giant calcite concretions in aeolian dune sandstones; sedimentological and architectural controls on digenetic heterogeneity, mid-Cretaceous Iberian Desert System, Spain, Sedimentary Geology, 243-244: 130-147.
Aydin, A. and Basu, A. (2005). The Schmidt hammer in rock material characterization, Engineering Geology, 81: 1-14.
Babiker, A.F.; Smith, C.C.; Gilbert, M. and Ashby, J.P. (2014). Non-associative limit analysis of the toppling-sliding failure of rock slopes, International Journal of Rock Mechanics & Mining Science, 71: 1-11.
Bahroudi, A. and Koyi, H.A. (2004). Tectono-sedimentary framework of the Gachsaran Formation in the Zagros foreland basin, Marine and Petroleum Geology, 21: 1295-1310.
Ballantyne, C.K.; Black, N.M. and Finlay, D.P. (1989). Enhanced boulder weathering under late-lying snowpatches, Earth Sur faces Processes and Landforms, 14: 745-750.
Barton, N. and Choubey, V. (1977). The shear strength of rock joints in theory and practice, Rock Mechanics, 10: 1-54.
Benedict, J.B. (1993). Influence of snow upon rates of granodiorite weathering, Colorado Front Range, USA. Boreas, 22: 87-92.
Berberian, M. (1995). Master blind thrust faults hidden under the Zagros folds: active basement tectonics and surface morphotextonics, Tectonophysics, 241: 193-224.
Bridge, J. and Demicco, R. (2008). Earth surface processes, landforms and sediment deposits, Cambridge university press, UK, 815 pp.
Colman, S.M. (1981). Rock-weathering rates as functions of time, Quaternary Research, 15: 250-264.
Day, M.J. and Goudie, A.S. (1977). Field assessment of rock hardness using the Schmidt test hammer, British Geomorphology Research Group Technical Bulletin, 18: 19-29.
Day, M.J. (1980). Rock hardness: field assessment and geomor phic importance, Professional Geographer, 32: 72-81.
Deere, D.U. and Miller, R.P. (1966). Engineering classification and index properties for intact rocks, Technical Report Number AFNL-TR-65-116, Air Force Weapon Laboratory, Kirtland Base, New Mexico.
Demirdag, S.; Yavuz, H. and Altindag, R. (2009). The effect of sample size on Schmidt rebound hardness value of rocks, International Journal of Rock Mechanics & Mining Sciences, 46: 725-730.
Dewers, T.; Newell, P.; Broome, S.; Heath, J. and Bauer, S. (2014). Geomechanical behavior of Cambrian Mount Simon Sandstone reservoir lithofacies, Iowa Shelf, USA, International Journal of Greenhouse Gas Control, 21: 33-48.
Ericson., K. (2004). Geomorphological surfaces of different age and origin in granite landscapes: an evaluation of the Schmidt test hammer, Earth Surface Processes and Landforms, 29: 495-509.
Goudie, A.S. (2006). The Schmidt Hammer in geomorphological research, Progress in Physical Geography, 30(6): 703-718.
Goudie. A.S. (2013). The Schmidt Hammer and Related Devices in Geomorphological Research, Treatise on Geomorphology, 338-345.
Gupta, V.; Sharma, R. and Prasad Sah., M.  (2009). An Evaluation of Surface Hardness of Natural and Modified Rocks Using Schmidt Hammer: Study from Northwestern Himalaya, India. Geografiska Annaler. Series A, Physical Geography, 91(3): 179-188.
Hall, K. (1993). Enhanced bedrock weathering in association with late-lying snowpatches – evidence from Livingston Island, Antarctica, Earth Surface Processes and Landforms, 18: 121-29.
Homke, S.; Verge´s, J.; Garce´s, B.; Emami, H. and Karpuz, R. (2004). Magnetostratigraphy of Miocene-Pliocene Zagros foreland deposits in the front of the Push-e Kush Arc (Lurestan Province, Iran), Earth and Planetary Science Letters, 225: 397-410
Hsieh, Y.; Li, H.; Huang, T. and Jeng, F. (2008). Interpretations on how the macroscopic mechanical behavior of sandstone affected by microscopic Properties-Revealed by bonded-particle model, Engineering Geology, 99: 1-10.
ISRM (1978). Suggested methods for determining hardness and abrasiveness of rocks. International Journal of Rock Mechanics and Mining Sciences, 15: 89-97.
Khidir, A. and Catuneanu, O. (2010). Reservoir characterization of Scollard-age fluvial sandstones, Alberta foredeep, Marine and Petroleum Geology, 27: 2037-2050.
Kimber, O.G.; Allison, R.J. and Cox., N.J. (1998). Mechanisms of failure and slope development in rock masses, Transactions of the Institute of British Geographers, 23(3): 353-370.
Lerman, A. and Meybeck, M. (1988). Physical and Chemical Weathering in Geochemical Cycles, Kluwer Academic Publishers, ISBN-13: 978-94-010-7881-8.
Luckman, B.H. (2015). Processes, Transport, Deposition, and Landforms: Rockfall, Earth Systems and Environmental Sciences, 7: 174-182.
Ansari, M.K.; Rajesh Singh, M. Ahmad and Singh, T.N. (2015). Correlation between Schmidt hardness and coefficient of restitution of rocks, Journal of African Earth Sciences, 104: 1-5.
Matasci, B.; Jaboyedoff, M.; Loye, A.; Pedrazzini, A.; Derron, M.-H and Pedrozzi, G. (2015). Impacts of fracturing patterns on the rockfall susceptibility and erosion rate of stratified limestone, Geomorphology, 241: 83-97.
Matthews, J.A.; Dawson, A.G. and Shakesby, RA. (1986). Lake shoreline development, frost weathering and rock platform erosion in an alpine periglacial environment, Jotunheimen, southern Norway, Boreas, 15: 33-50.
McCarroll, D. and Nesje, A. (1993). The vertical extent of ice sheets in Nordfjord, western Norway: measuring degree of rock surface weathering, Boreas, 22: 255-265.
Mobasher, K. and Babaie, H.A. (2008). Kinematic significance of fold- and fault-related fracture systems in the Zagros Mountains, southern Iran, Tectonophysics, 451: 156-169.
Moon B.P. and Selby., M.J. (1983). Rock mass strength and scarp forms in southern Africa, Geografiska Annaler, Series A, Physical Geography, 65(1/2).
Moore, J.R.; Sanders, J.W.; Dietrich, W.E. and Glaser, S.D. (2009). Influence of rock mass strength on the erosion rate of alpine cliffs, EARTH SURFACE PROCESSES AND LANDFORMS Earth Surf, Process. Landforms.
Motiee, H. (1993).Iran Geology, Stratigraphy of Zagros, Geological Survey & Mineral Explorations of Iran (GSI) press.
Navabpour, P. and Barrier, E. (2012). Stress states in the Zagros fold-and-thrust belt from passive margin to collisional tectonic setting, Tectonophysics, 581: 76-83.
Nespereira, J.; Blanco, J.A.; Yenes, M. and Pereira, D. (2010). Irregular silica cementation in sandstones and its implication on the usability as building stone, Engineering Geology, 115: 167-174.
Owen, G.; Matthews, J.A. and Albert, P.G. (2007). Rates of Holocene chemical weathering 'Little Ice Age' glacial ero sion and implications for Schmidt-hammer dating at a glacier foreland boundary, Fabergstolsbreen, Southern Norway, The Holocene, 17: 829-834.
Rune, A. Aa; Sjastad, J.; Sønstegaard, E. and Blikra, L.H. (2007). Chronology of Holocene rock-avalanche deposits based on Schmidt-hammer relative dating and dust stratigraphy in nearby bog deposits, Vora, inner Nordfjord, Norway. The Holocene 17, 7, pp. 955-964
Schmidt, E. (1951). A non - destructive concrete tester, Concrete, 59(8): 34-5.
Selby, M.J. (1980). A rock mass strength classification for geomorphic purposes: with tests from Antarctica and New Zealand, Zeitschrift fur Geomorphologie, 24(1): 31-51.
Selby, M.J. (1993). Hillslope materials and processes, Oxford Oxford University Press.
Sengun, N.; Altindag, R.; Demirdag, S. and Yavuz, H. (2011). P wave velocity and Schmidt rebound hardness value of rocks under uniaxial compressional loading, International Journal of Rock Mechanics and Mining Sciences, 48: 693-696.
Shalabi, F.; Cording, E.J. and Al-Hattamleh, O.H. (2007). Estimation of rock engineering properties using hardness tests, Engineering Geology, 90: 138-147.
Sheorey, P.R.; Barat, D.; Das, M.N.; Makerjee, K.P. and Singh, B. (1984). Schmidt hammer rebound data for estimation of large scale in situ coal strength, International Journal of Rock and Mining Science and Geomechanic Abstracts, 21: 39-42.
Sherkati, S. and Letouzey, J. (2004). Variation of structural style and basin evolution in the central Zagros (Izeh zone and Dezful Embayment), Iran, Marine and Petroleum Geology, 21: 535-554.
Sjoberg, R. and Broadbent, N. (1991). Measurement and calibration of weathering using the Schmidt hammer on wave washed moraines in the upper Norrland coast, Sweden, Earth Surface Processes and Landforms, 16: 57-64.
Smith, J.V. (2015). Self-stabilization of toppling and hillside creep in layered rocks, Engineering Geology, 196: 139-149.
Stocklin, J. (1968). Structural history and tectonics of Iran: a review, American Association of Petroleum Geologists Bulletin, 52: 1229-1258.
Strzelecki, M. (2011). Schmidt hammer tests across a recently deglacierized rocky coastal zone in Spitsbergen - is there a "coastal amplification" of rock weathering in polar climates? Polish Polar Research 32.
Thornton, L.E. and Stephenson, W.J. (2006). Rock Strength: A Control of Shore Platform Elevation, Journal of Coastal Research, 22(1): 224-231.
Torabi, S.R; Ataei, M. and Javanshi, M. (2010). Application of Schmidt rebound number for estimating rock strength under specific geological conditions, Journal of Mining & Environment, 1(2): 2010, 1-8.
Tucker, M.E. (1982). The Field description of sedimentary rocks, The Open University press comprises, UK, PP. 1-117.
Turkington; A.V. and Paradise, T.R. (2005). Sandstone weathering: a century of research and innovation, Geomorphology, 67: 229-253.
Turkington, A.V.; Phillips, J.D. and Campbell, S.W. (2005). Weathering and landscape evolution, Geomorphology, 67: 1-6.
Varnes, D.J. (1978). Slope movements: types and processes. In: Schuster, R.L., Krizek, R.J. (Eds.), Landslide Analysis and Control, Special Report No. 176. Transportation Research Board, Washington, DC, pp. 11-33.
Viles, H.; Goudie, A.; Grab, S. and Lalley, J. (2011). The use of the Schmidt Hammer and Equotip for rock hardness assessment in geomorphology and heritage science: a comparative analysis, Earth Surface Processes and Landforms, 36:10.1002/esp. v36.3, 320-333.
Varnes, D. J. 1978. Slope movement types and processes. In: Special Report 176: Landslides: Analysis and Control (Eds: Schuster, R. L. & Krizek, R. J.). Transportation and Road Research Board, National Academy of Science, Washington D. C., 11-33.
Waragai, T. (1999). Weathering processes on rock surfaces in the Hunza Valley, Karakoram, North Pakistan, Zeitschrift für Geomorphologie Supplementband, 119: 119-136.
Williams, R.B.G. and Robinson, D.A. (1983). The effect of surface texture on the determination of the surface hardness of rock using the Schmidt hammer, Earth Surface Processes and Landforms, 8: 289- 292.
White, K., Bryant, R. and Drake, N. 1998: Techniques for measuring rock weathering: application to a dated fan segment sequence in southern Tunisia. Earth Surface Processes and Landforms 23, 1031–43.
Yaalon, D.H. and Singer, S. (1974). Vertical variation in strength and porosity of calcrete (nari) on chalk, Shefela, Israel and in terpretation of its origin, Journal of Sedimentary Petrology, 44: 1016-1023.
Yılmaz, N.; Goktan, R. and Kibici, Y. (2011). Relations between some quantitative petrographic characteristics and mechanical strength properties of granitic building stones, International Journal of Rock Mechanics and Mining Sciences, 48(3): 506513.
Young, R.W.; Wray, R. A.L. and Young, A.R.M. (2009). Sandstone Landforms, Published by Cambridge University press, p. 1-304.
Young, R.P., Fowell, R.J., 1978. Assesing rock discontinuities. Tunnels and Tunnelling, 45–8.
Zamanzade, S.M.; Ahmadi, A. and Ahmadi, A.H. (2014). Effect of calcium carbonate and porosity in theCreation rocky slopes in Aghajari Formation, The first Iranian Conference Geographical sciences, Tehran, Iran.
 
 
 
پژوهش های جغرافیای طبیعی
دوره 49، شماره 2
تیر 1396
صفحه 259-281

فایل ها

سابقه مقاله

  • تاریخ دریافت: 17 مهر 1395
  • تاریخ بازنگری: 21 آذر 1395
  • تاریخ پذیرش: 12 دی 1395

هم رسانی

ارجاع به این مقاله

آمار