Estimation of rock engineering properties using hardness tests     

Faisal I. Shalabi  Edward J. Cording  Omar H. Al-Hattamleh 《Engineering Geology》2007,90(3-4):138-147

In engineering projects such as tunnels, dams, foundations, and slope stability, the strength and elastic properties of the intact rock affect both the project design and the construction operation. It is sometimes expensive and time consuming to perform direct tests to evaluate the engineering properties (such as strength, modulus of elasticity, and Poisson's ratio) of the intact rock. The purpose of this work is to investigate the relationships between the engineering properties of the intact rock and the different types of hardness (Schmidt, shore scleroscope, abrasion, and total hardness), which are relatively cheap and easy to evaluate. In this study, dolomite, dolomitic limestone, and shale rocks were used. For simplicity, linear statistical analyses were performed. The results show that there are good relationships between the engineering properties of the intact rock and its hardness. Also, the results of this study are compared well with the results obtained by other investigators conducted on different types of rocks.  相似文献   

Spatial prediction model and its application to chemistry of atmospheric precipitation in Jordan     

Omar Ali Al-Khashman  Qassem Y. Tarawneh 《Atmospheric Research》2007,84(4):399-409

This study is concerned with the spatial variability of some wet atmospheric precipitation parameters such as; pH, conductivity (EC). The study also depicts the spatial variability of some ions (cations and anions) of atmospheric precipitation in Jordan such as, Ca²⁺, Mg²⁺, Na⁺ and K⁺, HCO₃⁻, Cl⁻, NO₃⁻ and SO₄²⁻. The basis of the work is to establish a relationship through the cumulative semivariogram technique between the distance ratios and the spatial dependence structure of the chemical composition of atmospheric precipitation. All semivariogram models are constructed in this study in order to understand the behavior of the spatial distribution. The spatial distributions of rainwater parameters show differences from station to station which is expressed in terms of angle, where the larger the angle the weaker the correlation. The semivariogram (SV) models are constructed to show the variation of the rainfall chemistry in Jordan. The SV models show weak correlation between mountain and leeside mountain stations, i.e. mountain and desert stations. On the other hand, good correlations are observed when transferring from south to north of the country. The larger is the found angle, the weaker is the correlation. For most of the SV model the correlation is found to be very weak between desert and mountainous locality. The Standard Regional Dependence Factor (SRDF) is used for prediction of the distribution of rain fall parameters. It shows the relative error between observed and predicted values of rainwater parameters. The overall regional relative error between the observed and estimated concentrations remains less than 15%.  相似文献   

Developing artificial neural network models to predict allowable bearing capacity and elastic settlement of shallow foundation in Sharjah,United Arab Emirates     

Maher Omar  Khaled Hamad  Mey Al Suwaidi  Abdallah Shanableh 《Arabian Journal of Geosciences》2018,11(16):464

This research proposes the use of artificial neural network to predict the allowable bearing capacity and elastic settlement of shallow foundation on granular soils in Sharjah, United Arab Emirates. Data obtained from existing soil reports of 600 boreholes were used to train and validate the model. Three parameters (footing width, effective unit weight, and SPT blow count) are considered to have the most significant impact on the magnitude of allowable bearing capacity and elastic settlement of shallow foundations, and thus were used as the model inputs. Throughout the study, depth of footing was limited to 1.5 m below existing ground level and water table depth taken at the level of the footing. Performance comparison of the developed models (in terms of coefficient of determination, root mean square error, and mean absolute error) revealed that the developed artificial neural network models could be effectively used for predicting the allowable bearing capacity and elastic settlement. As such, the developed models can be used at the preliminary stage of estimating the allowable bearing capacity and settlements of shallow foundations on granular soils, instead of the conventional methods.  相似文献   

Surrogate-based parameter inference in debris flow model     

Maria Navarro  Olivier P. Le Maître  Ibrahim Hoteit  David L. George  Kyle T. Mandli  Omar M. Knio 《Computational Geosciences》2018,22(6):1447-1463

This work tackles the problem of calibrating the unknown parameters of a debris flow model with the drawback that the information regarding the experimental data treatment and processing is not available. In particular, we focus on the evolution over time of the flow thickness of the debris with dam-break initial conditions. The proposed methodology consists of establishing an approximation of the numerical model using a polynomial chaos expansion that is used in place of the original model, saving computational burden. The values of the parameters are then inferred through a Bayesian approach with a particular focus on inference discrepancies that some of the important features predicted by the model exhibit. We build the model approximation using a preconditioned non-intrusive method and show that a suitable prior parameter distribution is critical to the construction of an accurate surrogate model. The results of the Bayesian inference suggest that utilizing directly the available experimental data could lead to incorrect conclusions, including the over-determination of parameters. To avoid such drawbacks, we propose to base the inference on few significant features extracted from the original data. Our experiments confirm the validity of this approach, and show that it does not lead to significant loss of information. It is further computationally more efficient than the direct approach, and can avoid the construction of an elaborate error model.  相似文献   

Extreme water levels along the central Red Sea coast of Saudi Arabia: processes and frequency analysis     

Antony  Charls  Langodan  Sabique  Dasari  Hari Prasad  Knio  Omar  Hoteit  Ibrahim 《Natural Hazards》2021,105(2):1797-1814

Natural Hazards - Knowledge about extreme water levels is essential for efficient planning and design of coastal infrastructure. This study uses a high-resolution (~?60 m) coupled...  相似文献   

First Telescope of the Russian–Cuban Observatory     

Bisikalo  D. V.  Sachkov  M. E.  Ibrahimov  M. A.  Savanov  I. S.  Nalivkin  M. A.  Naroenkov  S. A.  Fateeva  A. M.  Shugarov  A. S.  Mata  Rudy Montero  Pons  Omar Rodriguez  Rodriguez Uratsuka  Marta R. 《Astronomy Reports》2022,66(1):38-41

Astronomy Reports - Beginning of operation of the first Russian–Cuban Observatory telescope, a wide-field 20-cm robotic telescope installed at the observational site optical station in...  相似文献   

Quantifying uncertainties in fault slip distribution during the Tōhoku tsunami using polynomial chaos     

Ihab Sraj  Kyle T. Mandli  Omar M. Knio  Clint N. Dawson  Ibrahim Hoteit 《Ocean Dynamics》2017,67(12):1535-1551

An efficient method for inferring Manning’s n coefficients using water surface elevation data was presented in Sraj et al. (Ocean Modell 83:82–97 2014a) focusing on a test case based on data collected during the Tōhoku earthquake and tsunami. Polynomial chaos (PC) expansions were used to build an inexpensive surrogate for the numerical model GeoClaw, which were then used to perform a sensitivity analysis in addition to the inversion. In this paper, a new analysis is performed with the goal of inferring the fault slip distribution of the Tōhoku earthquake using a similar problem setup. The same approach to constructing the PC surrogate did not lead to a converging expansion; however, an alternative approach based on basis pursuit denoising was found to be suitable. Our result shows that the fault slip distribution can be inferred using water surface elevation data whereas the inferred values minimize the error between observations and the numerical model. The numerical approach and the resulting inversion are presented in this work.  相似文献   

PITCHER PLANTS RECORDED FROM BRIS FOREST IN JAMBU BONGKOK, KUALA TRENGGANU, MALAYSIA     

Jumaat H Adam　Nurulhuda Edy Muslim　Abdul Halim Hashim　Abd Rahim Othman　Hafiza Abd Hamid　Gire Kibe Gopir　Lydia M Pilik　Ramlan Omar　Muhammad Barzani Qasim　Jumat Salimon　Sahibin Abd Rahim 　Marlia Mohd Hanafiah 《湿地科学》2005,3(3):183-189

1INTRODUCTION NepentheswhichareknownlocallyinPeninsular Malaysiaasperiukkerabelongtoamonogenericfami lyNepenthaceae.Atpresent,atotalofninespecies(excludingnaturalhybrids)arerecordedfromPenin sularMalaysia.Ofthese,fourspeciesareendemic,whilsttheotherfivespeciesarefoundoutsidethepen insula.Thespeciescanarbitrarilybeclassifiedinto thelowlandspeciesandthehighlandspecies(Clarke,2002;Shivas,1984;Kurata,1976).Threespeciesarefoundinthehighlandhabitatscom monlyatanelevationofabove1000mforaboves…  相似文献   

Flow Estimation in a Basin by Using a Hydrological Model: Application to the Basin of Wadi Djendjen (Jijel,North-East Algeria)     

Abdelmadjid Boufekane  Omar Saighi 《Water Resources》2018,45(4):523-531

The aim of this study was to transform the rain into flow in the basin of Wadi Djendjen by using a simulation model in absence of the continuous measurements of the flow. The obtained results indicated and confirmed the strong adaptability of this model with varied hydroclimatic situations. The validation process showed an interesting result, which lead to conclude that the model is well calibrated and has a good performance to be used for the basins with Mediterranean climate. The obtained results for the simulation by the GR2M model over the studied period (1973–1986) showed that there no significant difference between the obtained value for the yearly average flow (197.70 hm³) and that measured at Missa hydrometric station (200.80 hm³), which allow us to estimate quantitatively the flow in Missa hydrometric station. While, for the period of 2000–2012, the results showed that the yearly average flow value (171.90 hm³), is significantly different (reduction of 15% for 12 years), in comparison with that measured at Missa hydrometric station (200.80 hm³). This can be due to the dryness which struck the region since 2000, and the local degradation of the forest ecosystem, which has considerably affected the runoff surface.  相似文献   

Bayesian inference of spatially varying Manning’s n coefficients in an idealized coastal ocean model using a generalized Karhunen-Loève expansion and polynomial chaos     

Siripatana  Adil  Le Maitre  Olivier  Knio  Omar  Dawson  Clint  Hoteit  Ibrahim 《Ocean Dynamics》2020,70(8):1103-1127

Ocean Dynamics - Bayesian inference with coordinate transformations and polynomial chaos for a Gaussian process with a parametrized prior covariance model was introduced in Sraj et al. (Comput...  相似文献