17 research outputs found
The Effect Of The Rockmass Properties And Groundwater Inflow Related To Performance Of Tunnel Boring Machine (Tbm) At Pahang Selangor Raw Water Transfer Tunnel Project (Psrwt
Groundwater inflow into tunnels can constitute a potential hazard and an important
factor influencing the performance of tunnel excavation. In this research, the results
on analyses of localised jointing system are presented to study the link of
groundwater inflow and the joint orientations along the 2000 meters of TBM-1 site,
Karak in conjunction to the construction of Pahang Selangor Raw Water Transfer
Tunnel project (PSRWT). The geology along the tunnel route is predominantly the
Main Range granite batholith with a lesser extent of meta-sedimentary rocks of the
Karak Formation. Structurally, TBM-1 is dominated by joints orientated at N-S,
NW-SE and NE-SW direction. Faults that cross-cut the intrusive Main Range
Granite rocks trending faults formed the most prominent structures in the vicinity of
the Karak. Potential leakage places are identified of three main types of joints
orientations; the most permeable place is parallel along the main lineament
orientation, followed by perpendicular to 90 degrees to the tunnel drive direction, 45
degrees to the lineament line or combinations of both joints and crossing some of
voids which creating pocket water zones. At least three sets of prominent
topographic lineaments correspond to fault-zones permeability related. Based on the
stereographical projection and rosette diagram analysis, the dominant orientations of
joints seem to have occurred at the intersection of 3 cross-cutting trends. They are the
Kuala Lumpur – Bukit Tinggi trend, N-S trend and NE-SW trend, which corresponds
to the NW-SE Bukit Tinggi and Kuala Lumpur Fault Zones, the N-S faults and the
NE-SW faults, respectively. Results from the mechanical tests, Uniaxial
Compressional Strength Test, Brazillian Tensile Test, Triaxial by comparing dry and
wet condition of rockmass showed that the value of rockmass strength were lessened
into half. Parameter values that obtained from the mechanical tests were used in the
finite element method analysis showed that rockmass with poor grade and in wet
condition have higher potential to deform compared to dry and higher grade rock
Impact of Thermal Maturation of the Upper Cretaceous Bituminous Limestone of Attarat Um Ghudran Central Jordan on Calcareous Nannofossil Preservation
Oil shale deposits of the Late Cretaceous from three boreholes in central Jordan were examined to assess the impact of thermal maturation on the content of nannofossils. Thermal activity has been shown to have a strong effect on organic matter content and composition but its effect on calcareous nannofossil assemblages remains inconclusive. This study aims to determine the impact of thermal maturation on nannofossil assemblages and to compare this to an estimated maturity level based on bulk geochemical analysis. Micropaleontological and geochemical analyses were conducted on 31 samples from three oil shale wells drilled in Attarat Um Ghudran central Jordan. Several types of nannofossil preservation have been recorded, including dissolution, overgrowth, and breakage. In the Jordan oil shale sections, nannofossils exhibit a variety of preservation types, with intense dissolution in the middle part of the study sections. The vast majority of the samples had high TOC enrichment, with 29 samples exceeding values of \u3e10%. Kerogen recovery and quality from the oil shale are very good, with a predominance of fluorescent amorphous organic matter (AOM) and minor algal components. The low fluorescence preservation index (FPI), which is 1 in most of the samples, indicates that alteration occurred due to intense thermal activities in the study interval. The palynomorph and AOM fluorescence, ranging from a spore coloration index (SCI) of 3 to 5, suggest that the studied samples were approaching the oil window. A correlation between the nannofossil preservation and geochemical parameters shows a predominance of poorly preserved nannofossils along with high total organic carbon contents and an elevated hydrogen index (HI). We show that low FPI values and a higher level of maturity are associated with poor nannofossil preservation, suggesting that nannofossils, in conjunction with petrographic analysis of kerogen, could be used as a rapid screening technique for estimating levels of oil-shale maturity. The nature of the tectonism in the study area, including faulting and a metamorphosed zone, enhanced the maturity, which might explain why the nannofossils were so significantly affected
Groundwater potential zone in Bachok District, Malaysia: Application of Remote Sensing and GIS Technique
The research aimed to identify probable groundwater zones by integrating GIS, remote sensing, and AHP techniques. Given the rising demand for water resources due to population growth and economic expansion, groundwater resources are vital. The paper presented a comprehensive approach to achieving this goal. Integrating geographic information systems with analytic hierarchy processes is demonstrated to obtain precise decision-making information through transforming geographical data and weightage ranking. The present study has identified seven principal criteria controlling parameters significantly impacting groundwater occurrence. These criteria have been derived from analysing satellite imagery, existing maps, and data sources. The abovementioned variables encompass drainage density, elevation, annual precipitation, slope gradient, land use and land cover. The overlay-weighted sum method maps the potential groundwater zones in the research area by incorporating all thematic criteria. The groundwater potential index map has identified various zones with differing levels of groundwater potential, ranging from very low (1.61%, low (1.81%), moderate (2.66%), high (22.59%) and very high (71.33%). Ultimately, the mean groundwater level information obtained from five wells in the study area is employed to authenticate the map depicting the potential groundwater zones. This research discusses the significant implications that need to be considered for sustainable groundwater exploration in the area
Application of a Comprehensive Rock Slope Stability Assessment Approach for Selected Malaysian Granitic Rock Slopes (Pengaplikasian Pendekatan Penilaian Kestabilan Cerun Batu Komprehensif untuk Cerun Batu Granit Malaysia yang Terpilih)
In Malaysia, rock slope stability analysis has been largely confined to kinematic analysis with rock mass rating
systems as assessment tools for stability analysis. While this method addresses the fundamental issues of rock slope
stability including identifying potential failure modes, an information gap still exists between geologists and engineers
in designing proper mitigation measures for rock slopes. This paper aims to address this issue by incorporating several
methodologies, including kinematic analysis, slope mass rating and the Barton-Bandis criterion for the limit equilibrium
method. Four rock slopes with potential instabilities namely KSA, KSB, LHA, and LHB were studied. KSA and KSB were
located near Kajang, Selangor while LHA and LHB were located near Rawang, Selangor. Each slope exhibits multiple
potential failures, with attention given on sliding-type failures in planar or wedge form. A slope mass rating value was
assigned to each potential failure based on rock mass ratingbasic and the slope mass rating based on readjustments for
discontinuity orientation and excavation method. Factor of safety from limit equilibrium method show potentially
unstable blocks and failed blocks (Factor of Safety <1.00) with confirmation on site. Water filling of discontinuity
apertures plays an important role in destabilizing rock blocks, especially in wet conditions experienced in Malaysia’s
tropical climate. Several geometries are identified as potentially unstable due to low slope mass rating (Class V) and
factor of safety of <1.2, such as planar J5 and wedge J2*J5 at KSA, wedge forming with sets J3, J4 and fault plane at
KSB, planar J2 at LHA, and wedge J3*J4 at LHB. Stabilization structures such as rock bolts can be better designed with
the determined factor of safety values coupled with relevant geological and geotechnical inputs. In this comprehensive
rock slope stability assessment approach, limit equilibrium method serves as a useful method in analyzing rock slope
stability to complement kinematic analysis and stability ratings often used in Malaysia
Coal adsorption: comparison between the 3D imaging of gas sorption isotherms by X-rays computed tomography – a review
This study improves the characterization and measurement of gas interactions with coal porosity. Due to the complex structural and chemical properties present at various scales, natural micropore media such as coals (i.e. shales, mudstone) are difficult to define. Large surface area for gas sorption on micropore materials. The ability to estimate gas reserves, flow, and storage for increased recovery and CO2 sequestration is crucial in oil and gas applications. Other uses include industrial CO2 collection, hydrogen storage on sorbent surfaces, and ammonia synthesis heterogeneous catalysis. To understand the gas–solid interaction, high-resolution experiments are required. To increase quantitative agreement between CT-derived results, micro- to macro-millimeter CT imaging was used on coal samples (low rank). The importance of gas sorption in sophisticated micropore media is highlighted in relation to CT imaging mass balance data. On the Balingian, Sarawak sample, micro scan CT revealed that the operation may be reproduced on a lab size. These findings demonstrated the DRB method’s dependability for a wider deployment of digital adsorption research in micropore geomaterials
Hydraulic fracturing as unconventional production potential for the organic-rich carbonate reservoir rocks in the Abu El Gharadig Field, north western Desert (Egypt) : evidence from combined organic geochemical, petrophysical and bulk kinetics modeling results
Groundwater potential zone in Bachok District, Malaysia: Application of Remote Sensing and GIS Technique
The research aimed to identify probable groundwater zones by integrating GIS, remote sensing, and AHP techniques. Given the rising demand for water resources due to population growth and economic expansion, groundwater resources are vital. The paper presented a comprehensive approach to achieving this goal. Integrating geographic information systems with analytic hierarchy processes is demonstrated to obtain precise decision-making information through transforming geographical data and weightage ranking. The present study has identified seven principal criteria controlling parameters significantly impacting groundwater occurrence. These criteria have been derived from analysing satellite imagery, existing maps, and data sources. The abovementioned variables encompass drainage density, elevation, annual precipitation, slope gradient, land use and land cover. The overlay-weighted sum method maps the potential groundwater zones in the research area by incorporating all thematic criteria. The groundwater potential index map has identified various zones with differing levels of groundwater potential, ranging from very low (1.61%, low (1.81%), moderate (2.66%), high (22.59%) and very high (71.33%). Ultimately, the mean groundwater level information obtained from five wells in the study area is employed to authenticate the map depicting the potential groundwater zones. This research discusses the significant implications that need to be considered for sustainable groundwater exploration in the area
Integration methods to predict the rock mechanical behavior using RocSlope
This paper proposes a method to predict mechanical failure-mechanicsm. This method is capable of predicting failure mechanism of diverse geo-hazards, such as landslides, rock slope failures, etc. The method uses the displacement or strain divergence phenomenon in the fatal phase of failure to predict failure mechanism irrespective of failure mechanism, lithology and other parameters. Using the proposed method (RocSlope), prediction of failure mechanism of case histories was done (Rock mass failure and landslides) and laboratory studies (creep tests). In most cases, safe predictions were obtained. RocSlope, is a simple, quick and reliable practical method that revealed independency to volume of failure, lithology and failure mechanism. In addition, two empirical relations to estimate the terminal phase of failure and the critical deformation rate were developed, these practical relations complement the RocSlope method. This research will analysed rock orginally from a cool temperate region in West Hokkaido,Japan was presented. A rock slope deformations of jointed-chert rock were monitored using six surface fracturedisplacement sensors. Some movements that could be related to joint growth were observed. With the RocSlope, rock mass and rock deformations were numerically analysed and joints deformations were dominantly caused by thermal fatigue. Affects of the minor freezing on deformation of rock slope can be seen were observed