نشریه علوم زمین خوارزمی

نشریه علوم زمین خوارزمی

تدوین یک رویکرد عمدتاً نظری برای استنتاج سختی‌های کشسان زهکشی‌شده ناهمسانگرد در خاک‌های دانه‌ای اشباع بر اساس ویژگی‌های زهکشی‌نشده

نویسنده
احسان پگاه
دانشگاه خوارزمی
10.22034/KJES.2025.11.2.107023
چکیده
سختی‌های کشسان ناهمسانگرد در رسوبات خاک‌های دانه‌ای نقش مهمی در تحلیل بسیاری از مسائل مهندسی ژئوتکنیک و زمین‌شناسی مهندسی دارند. در این مطالعه، امکان محاسبه سختی‌های کشسان زهکشی‌شده در خاک‌های دانه‌ای اشباع بر اساس ویژگی‌های زهکشی‌نشده بررسی شد. با فرض ناهمسانگردی متقاطع در خاک‌های دانه‌ای، مجموعه‌ای از معادلات بر مبنای اصول نظریه‌ی کشسانی از پیشینه‌ی تحقیق استخراج شدند که در ترکیب با یک رابطه تجربی توسعه‌داده‌شده در این مطالعه، ارتباط بین پارامترهای زهکشی‌شده و زهکشی‌نشده را بیان می‌کنند. سپس، رویکردی نوین برای محاسبه مدول‌های یانگ زهکشی‌شده ناهمسانگرد از دو مؤلفه‌ی ناهمسانگرد مدول برشی و مؤلفه‌ی قائم مدول یانگ در شرایط زهکشی‌نشده ارائه شد. برای ارزیابی دقت و اعتبار این رویکرد، داده‌های مربوط به ویژگی‌های کشسان ناهمسانگرد حاصل از 46 آزمون آزمایشگاهی روی 7 نمونه خاک دانه‌ای متفاوت متعلق به 3 نوع خاک از مکان‌های مختلف جهان، از پیشینه گردآوری شد. مدول‌های یانگ زهکشی‌شده ناهمسانگرد برای هر آزمون با روش پیشنهادی محاسبه و با مقادیر مستقیماً اندازه‌گیری‌شده مقایسه شدند. نتایج نشان‌دهنده‌ی توافق مطلوب بین مقادیر محاسبه‌شده و مقادیر واقعی بود. یافته‌های این مطالعه می‌تواند به عنوان مرجعی مناسب برای توصیف منطقی و مقرون‌به‌صرفه‌ی سختی‌های کشسان ناهمسانگرد در رسوبات خاک‌های دانه‌ای اشباع با بهره‌گیری از تکنیک‌های غیرمخرب لرزه‌ای به‌کار گرفته شوند.
کلیدواژه‌ها
خاک‌های دانه‌ای اشباع
ناهمسانگردی متقاطع
سختی کشسان زهکشی‌شده
سرعت امواج لرزه‌ای
روش‌های غیرمخرب لرزه‌ای

عنوان مقاله English

Formulation of a largely theoretical approach for inferring anisotropic drained elastic stiffnesses in saturated granular soils from undrained features

نویسنده English

Ehsan Pegah
Kharazmi University
چکیده English

The anisotropic elastic stiffnesses of granular soil sediments play an important role in analyzing many geotechnical and geological engineering problems. In this study, the feasibility of calculating drained elastic stiffnesses in saturated granular soils based on undrained features was investigated. By assuming cross-anisotropy in granular soils, a set of equations from the theory of elasticity was extracted from the literature and then combined with an experimentally developed relationship in this study to establish a link between drained and undrained parameters. Subsequently, a novel approach was proposed for computing the drained anisotropic Young’s moduli from two anisotropic components of the shear modulus and the vertical component of the Young’s modulus under undrained conditions. To evaluate the accuracy and reliability of the proposed approach, data related to anisotropic elastic parameters from 46 laboratory tests conducted on seven different soil specimens representing three types of sand from various sites worldwide were compiled from the literature. The drained anisotropic Young’s moduli for each test were then calculated using the proposed method and compared with directly measured values. The results showed a strong agreement between the calculated and measured moduli, confirming the validity and efficiency of the developed approach. The findings of this study can serve as a reliable basis for the rational and cost-effective characterization of anisotropic elastic stiffnesses in saturated granular soils using nondestructive seismic testing techniques.

کلیدواژه‌ها English

Saturated granular soils
Cross-anisotropy
Drained elastic stiffness
Undrained elastic features
Seismic waves velocity
Nondestructive seismic methods
Anhdan, L., Koseki, J., 2005. Small strain behavior of dense granular soils by true triaxial tests. Soils and Foundations 45 (3), 21-38.
Bellotti, R., Jamiolkowski, M., Lo Presti, D.C.F., O’Neill, D.A., 1996. Anisotropy of small strain stiffness in Ticino sand. Geotechnique 46 (1), 115-131.
Chowdhury, R.N., King, G.J.W., 1971. Discussion: Anisotropic elastic parameters for soil. Geotechnique 21 (2), 181-183.
Chowdhury, R.N., King, G.J.W., 1972. Discussion: Anisotropic elastic parameters for soil. Geotechnique 22 (1), 183-185
Clayton, C.R.I., 2011. Stiffness at small strain: research and practice. Geotechnique 61, 1, 5-37.
Das, B.M., Ramana, G.V., 2011. Principles of Soil Dynamics, 2nd Edition, Cengage Learning, Stamford, USA.
Das, B.M., Sobhan, K., 2014. Principles of Geotechnical Engineering, 4th ed. Cengage Learning, Stamford, USA.
Dutta, T.T., Otsubo, M., Kuwano, R., Sato, T., 2020. Estimating multidirectional stiffness of soils using planar piezoelectric transducers in a large triaxial apparatus. Soils and Foundations 60, 1269- 1286.
Ezaoui, A., Di Benedetto, H., 2009. Experimental measurements of the global anisotropic elastic behaviour of dry Hostun sand during triaxial tests, and effect of sample preparation. Geotechnique 59 (7), 621-635.
Fioravante, V., 2000. Anisotropy of small strain stiffness of Ticino and Kenya sands from seismic wave propagation measured in triaxial testing. Soils and Foundations 40 (4), 129-142.
Fioravante, V., Giretti, D., Jamiolkowski, M., 2013. Small strain stiffness of carbonate Kenya Sand. Engineering Geology 161, 65-80.
Foti, S., Lai, C.G., Rix, G., Strobbia, C., 2015. Surface wave methods for near-surface site characterization, 1st Edition, CRC Press, Taylor and Francis Group, New York, USA.
Gibson, R.E., 1974. The analytical method in soil mechanics. Geotechnique 33 (2), 165-180.
Graham, J., Houlsby, G.T., 1983. Anisotropic elasticity of a natural clay. Geotechnique 33 (2), 165-180.
Gu, X.Q., Hu, J., Huang, M., 2017. Anisotropy of elasticity and fabric of granular soils. Granular Matter, 19:33.
Gu, X.Q., Yang, S., 2018. Why the OCR may reduce the small strain shear stiffness of granular materials? Acta Geotechnica 13, 1467-1472.
Gu, X.Q., Yang, J., Huang, M., Gao, G., 2015. Bender element tests in dry and saturated sand: Signal interpretation and result comparison. Soils and Foundations 55 (5), 951-962.
He, H., Li, M., Senetakis, K., 2017. A note on influence of stress anisotropy on the Poisson’s ratio of dry sand. Journal of Rock Mechanics and Geotechnical Engineering 9, 1159-1164.
Hoque, E., Tatsuoka, F., 2004. Effects of stress ratio on small-strain stiffness during triaxial shearing. Geotechnique 54 (7), 429-439.
Ivanov, J., Miller, R.D., Feigenbaum, D., Morton, S.L.C., Peterie, S.L., Dunbar, J.B., 2017. Revisiting levees in southern Texas using Love-wave multichannel analysis of surface waves with the high-resolution linear Radon transform. Interpretation 5 (3), T287-98.
Khan, Z., Cascante, G., Hesham EI Naggar, M., 2011. Measurement of dynamic properties of stiff specimens using ultrasonic waves. Canadian Geotechnical Journal 48, 1-15.
Kumar, J., Madhusudhan, B. N., 2010. Effect of relative density and confining pressure on Poisson ratio from bender and extender elements tests. Geotechnique 60 (7), 561-567.
Kuwano, R., 1999. The stiffness and yielding anisotropy of sand. PhD Thesis, University of London (Imperial College).
Kuwano, R., Jardine, R.J., 2002. On the applicability of cross-anisotropic elasticity to granular materials at very small strains. Geotechnique 52 (10), 727-749.
Lings, M. L., 2001. Drained and undrained anisotropic elastic stiffness parameters. Geotechnique 51, 6, 555-565.
Nishimura, S., 2014. Cross-anisotropic deformation characteristics of natural sedimentary clays. Geotechnique 64, 12, 981-996.
Pegah, E., Gu, X.Q., Liu, H., 2024. Fabric anisotropy of granular soils and its dependency on grading and particles specifications. Acta Geotechnica 19, 7619-7633.
Pegah, E., Liu, H., 2016. Application of near-surface seismic refraction tomography and multichannel analysis of surface waves for geotechnical site characterizations: A case study. Engineering Geology 208, 100-113.
Pegah, E., Liu, H., 2020a. Evaluation of hyperbolic stress-strain and bulk-modulus model parameters in granular soil mass using seismic surveying. Engineering Geology 266, 105456.
Pegah, E., Liu, H., 2020b. Evaluating the overconsolidation ratios and peak friction angles of granular soil deposits using noninvasive seismic surveying. Acta Geotechnica 15, 3193-3209.
Pegah, E., Liu, H., 2025. Determination of cross-anisotropic elastic constants of in situ soils using joint application of seismic refraction and downhole surveys. Transportation Geotechnics 55, 101689.
Pegah, E., Liu, H., Dastanboo, N., 2017. Evaluation of the lateral earth pressure coefficients at-rest in granular soil deposits using the anisotropic components of S-wave velocity. Engineering Geology 230, 55-63.
Pegah, E., Liu, H., Gholami, A., 2021. Estimating drained cross-anisotropic elastic parameters in saturated clays using the undrained properties. Engineering Geology 293, 106340.
Pegah, E., Liu, H., Gu, X.Q., Gholami, A., 2022. A semi-analytical approach for efficient calculation of drained cross-anisotropic elastic moduli in saturated granular soils from undrained attributes. Computers and Geotechnics 148, 104794.
Pegah, E., Mahmoodi, M., Siavashpoo, A., 2016. Evaluation of seismic hazard and site geodynamic properties by using geophysical methods in the north of Iran. Journal of Civil Engineering and Construction 5 (2), 126-142.
Sloan, S. D., Nolan, J. J., Broadfoot, S. W., McKenna, J. R., Metheny, O. M., 2013. Using near-surface seismic refraction tomography and multichannel analysis of surface waves to detect shallow tunnels: A feasibility study. Journal of Applied Geophysics 99, 60-65.
Talaee Firozjaee, F., Pegah, E., Misaghi, A., 2024. Fabric anisotropy in sands and assessing its dependence on grading and surface appearance parameters. Kharazmi Journal of Earth Sciences 10 (1), 73-90.
Uyanik, O., 2011. The porosity of saturated shallow sediments from seismic compressional and shear wave velocities. Journal of Applied Geophysics 73, 16-24.
Xia, J., 2014. Estimation of near-surface shear wave velocities and quality factors using multichannel analysis of surface-wave methods. Journal of Applied Geophysics 103, 140-151.
Zhu, Y., Gong, J., Nie, Z., 2020. Numerical investigation of the elastic properties of binary mixtures as a function of the size ratio and fines content. International Journal of Geomechanics 20 (9), 04020155.