کاربرد رده بندی توده سنگ جهت تخمین تزریق پذیری (مطالعات موردی)

با استفاده از طبقه بندی توده سنگ به روش شاخص مقاومت زمین شناسی می توان اقدام به ارزیابی نفوذپذیری و تزریق پذیری توده های سنگی نمود. در این مقاله با انجام طبقه بندی شاخص مقاومت زمین‌شناسی میزان محدوده نفوذپذیری توده‌های سنگی براساس لوژان بر روی چارت طبقه بندی زون بندی شده است. در این چارت میزان gsi بیش از 55 محدوده لوژان 13 یا نفوذناپذیر ، میزان gsi بین 45 تا 55 محدوده لوژان 3 تا 10 یا نفوذپذیری کم ، میزان gsi بین 35 تا 45 محدوده لوژان 10 تا 30 یا نفوذپذیری متوسط و میزان gsi کمتر از 35 محدوده لوژان 30 تا 100 یا نفوذپذیری زیاد را نشان می‌دهند. پس از انجام این زون بندی در چارت طبقه‌بندی شاخص مقاومت زمین‌شناسی اقدام به تخمین تزریق پذیری و بهسازی توده های سنگی گردیده است. زون اول ناحیه بدون توان تزریق‌پذیری (none groutable) می‌باشد. زون دوم ناحیه با تزریق‌پذیری محدود که به صورت محلی (local) میباشد. زون سوم ناحیه با تزریق پذیری متوسط (medium groutable) می‌باشد. زون چهارم ناحیه با تزریق پذیری بالا (high groutable) می‌باشد.

application of rock mass classification in estimating of groutability(case studies)

1 introduction one of the conventional field methods for determine permeability of rock masses is lugeon test. the absorption is specific with division water permeability test (lugeon) on the number of joints. the secondary permeability index (spi) relative to the specific joint that included the degree of joints, consistency joints, and void filling. the secondary permeability index obtained based on dams foundation classification for improvement dams foundation and rock masses classification. the secondary permeability index relative to rock mass permeability. the lugeon test is a way for determination secondary permeability index in dams foundation. the geological strength index that the results of this test were used for evaluation groutability of rock masses. in the classification of rock masses, geological strength index is better than other classification of rock masses because geological strength index noticed the roughness of surface joint in rock masses and structure rock masses with interlocking components. the roughness has a direct relation with hydrology parameters in rock masses — the geological strength index preference for groutability. the geological strength index is not noticing to the in situ stress and underground water — the estimation efficiency joints by log excavation and outcrops. the surface condition rating concluded: roughness, weathering and filling. this parameters collection thogether and determination of scr. the structure rating determination by rock quality designation  (rqd( equations (3,4). the geological strength index classification of rock masses can be used for evaluation the permeability and groutability. the groutability determination by absorption specific.  this estimation is easy, rapid and without additional cost to the project and provide an estimation will be important role in allocation cost exploration, project management and programming.   2 methodology  in this paper, permeability and groutability are evaluated by lugeon and geological strength index in several dams. in this regard the groutability estimations are more or less in this relation, it is possible to zone the gsi chart based on lugeon number. in this research used of 200 lugeon test and geological strength index classifications. their projects selected for estimation. these projects include karun 2 dam, jamishan reservoir dam, and veniar reservoir dam. the 120 data used for the main chart and 80 data for validation. the structure rating (sr), surface condition rating (scr), and lugeon determination in geological strength index chart. the permeability zones determined and the groutability zones evaluated. the zonation in the chart has a suitable correlation.    3findings in the chart of figure 1, for gsi more than 55, the lugeon between 1 to 3 or impermeable, the range of gsi between 45 to 55 equal to lugeon 3 to 10 or low permeability, the range of gsi between 35 to 45 equal to lugeon10 to 30 or medium permeability. also, gsi less than 35 is lugeon between 30 to100 or high permeability. the three boundary zone determination on geological strength index. the boundary one zone is sr=30 or blocky/disturbed/seamy to blocky middle boundary in the vertical axis, and horizontal axis included total scr. the twozone is disintegrated to middle very blocky in the vertical axis, and horizontal axis included total scr. the threezone is boundary laminated/sheared to middle boundary blocky/disturbed/seamy in the vertical axis and boundary good to very poor in the horizontal axis.    after the zoning in geological strength index chart, groutability and ground treatment of rock masses estimated. the first zone is without groutability (none groutable), the second zone has the local groutability (local groutable, the third zone has the medium groutability (medium groutable) and the fourth zone has the high groutability (high groutable). this chart application in sedimentary and igneous rocks. this rocks include: limestone, sandstone, gabbro and diabase. this chart not application for fragmentation and impermeability rocks. for example shale and schist. the boundary of zonation has some vacillation it can improve in research future.     figure 1. zonation in chart of geological strength index with groutability and ground improvement   4conclusion in this chart, for gsi more than 55, the lugeon between 1 to 3 or impermeable, the range of gsi between 45 to 55 equal to lugeon 3 to 10 or low permeability, the range of gsi between 35 to 45 equal to lugeon10 to 30 or medium permeability. also gsi less than 35 is lugeon between 30 to100 or high permeability. based on the zonation in the chart, four zones namely none groutable, locally groutability, medium groutable and high groutable were identified. the zonation in chart also have a suitable correlation. this estimation is easy, rapid and without additional cost to the project and provide an estimation that will decrease exploration cost, project management and programming. in this paper, permeability and groutability are evaluated by lugeon and geological strength index for sealing and consolidation rock masses. the recommended that examination accomplished in zonation of geological strength index and groutability for more exactly boundary zonation.   references azimian, a., ajalloeian, r., 2015. permeability and groutability appraisal of the nargesi dam site in iran based on the secondary permeability index, joint hydraulic aperture and lugeon tests. bulletin of engineering geology and the environment 74, 845859. barton,  n., 2008. workshop rock engineering for drill and blast and tbm tunneling and important aspects of rock mass behavior, iran. cai., m., kaiser, uno, h., tasaka, y., minami, m., 2004. estimation of rock mass deformation  modulus and strenght of jointed hard rock masses using the gsi system. international journal of rock mechanics and mining sciences 41, p: 319. ewert, f. k., 1985. rock grouting with emphesises on dam sites, springerverlag, berlin, heidelberg. ewert, f. k., 2005. hydrofracturing of latent discontinuties in rock and implication for successful and economical execution of grouting, dam engineering 16, 556. foyo, a.m.a., sanchez, c., tomillo., 2005. a proposal for secondary permeability index obtained from water pressure test in dam foundations. engineering geology 77, 6982. houlsby, a.c., 1990. construction and design of cement grouting, john willy sons, p: 422. kayabasi, a., akgun, a., gokceoglu, c., hoek, e., martinos, p., martinos, v., 2005. characterization and engineering properties of tectonically undisturbed but lithologically varied sedimentary rock masses under publication. international journal of rock mechanics and minings sciences 42, 277285. rostami baran, h. r., lashkaripour, gh., ghafoori, m., 2014. a proposal for geological groutability index (ggi) of cement grouting in rock foundations. indian journal of science and technology 7, 95103. sonmez, h., ulusay, r., 2002. a discussion  on  the hoekbrown  failure  criterion  and suggested  modifications  to  the  criterion  verified  by  slope  stability  case  studies. yerbilimleri 26, 77 99. uromeihy, a., farrokhi, r., 2011. evaluating groutability at the kamalsaleh dam based on lugeon tests. bulletin of engineering geology and the environment 71, 5063. zeidabadi nezhad, h., ajalloeian, r., azimian, a., 2012. evaluation of geological and engineering geological properties of cheshmehasheq dam site, ejge 17, 26332644.