@article{rafiei_rahman_gabr_2023, title={Evaluation of wave-induced instability of nearly saturated sandy slopes under partially undrained condition: A case study of landslide in Fraser River delta front}, volume={159}, ISSN={["1873-7633"]}, DOI={10.1016/j.compgeo.2023.105496}, abstractNote={A significant amount of Methane gas in soil deposits at Fraser River Delta (FRD), Canada, was identified as it adversely impacted the stability of the sloping seabed in the area under waves and tides. In this study, an integrated FEM model is utilized to investigate the instability of FRD front due to 1985 storm waves. Despite earlier studies that focused only on the role of residual pore pressure reached at late wave cycles in inducing the slide of FRD front (using empirical correlations), the transient response of sediments at early wave cycles is considered herein. The effect of coupled-flow-and-deformation processes within the sediments on the extent of the sliding plane is considered. For wave-seabed interaction modeling, Biot's poroelasticity and linear wave theory are employed to represent the fluid and seabed domains, respectively. The slide evaluation of the sloping seabed is conducted using Strength Reduction Technique with Mohr-Coulomb failure criterion. The results indicate that the storm waves cause a shallow slide within the slope, and the proximity of the unsaturated layer to mudline exacerbated the instability condition. Moreover, instantaneous liquefaction zones are found to emerge away from the slope; thus, they may not lead to an exacerbated sliding of the slope.}, journal={COMPUTERS AND GEOTECHNICS}, author={Rafiei, Amin and Rahman, M. S. and Gabr, M. A.}, year={2023}, month={Jul} }
 @article{rafiei_rahman_gabr_2022, title={Response and Instability of Sloping Seabed Supporting Small Marine Structures: Wave - Structure-Soil Interaction Analysis}, volume={144}, ISSN={["1528-896X"]}, DOI={10.1115/1.4052864}, abstractNote={Abstract}, number={3}, journal={JOURNAL OF OFFSHORE MECHANICS AND ARCTIC ENGINEERING-TRANSACTIONS OF THE ASME}, author={Rafiei, Amin and Rahman, M. S. and Gabr, M. A.}, year={2022}, month={Jun} }
 @article{rafiei_rahman_gabr_ghayoomi_2021, title={Analysis of wave-induced submarine landslides in nearly saturated sediments at intermediate water depths}, volume={40}, ISSN={1064-119X 1521-0618}, url={http://dx.doi.org/10.1080/1064119X.2021.2001610}, DOI={10.1080/1064119X.2021.2001610}, abstractNote={Abstract Evaluation of wave impacts on submarine landslides is an essential element in geohazard studies. The slight desaturation of sediments (due to dissociation of gas hydrates) has been found to adversely impact the slide of the sloping seabed in the Fraser River Delta in Canada. In this study, to investigate the role of wave action on the slide of partially saturated seabed slopes, an integrated FEM model is developed. Despite most earlier studies that used a simplified decoupled undrained analysis, in this article, a more realistic model for coupled flow-and-deformation processes (within the sediments) and fluid-seabed interaction is utilized. Linear wave theory and Biot’s poroelasticity for the fluid and seabed domains are considered, respectively, and continuity of flux and traction is enforced along the interface of the media. The instability of the sloping seabed is investigated using strength reduction finite element method (SRFEM) with Mohr-Coulomb failure criterion. The limitation of limit equilibrium methods in the evaluation of submarine landslides is shown through comparison with SRFEM analyses where partly-dynamic and quasi-static idealizations of seabed response are considered. Finally, the adverse impacts of slight desaturation on seabed instability are assessed, and the reduction of the stability number with seabed steepness is presented.}, number={12}, journal={Marine Georesources & Geotechnology}, publisher={Informa UK Limited}, author={Rafiei, Amin and Rahman, M. Shamimur and Gabr, Mohammed A. and Ghayoomi, Majid}, year={2021}, month={Nov}, pages={1411–1423} }
 @article{cen_du_wang_yan_rahman_2021, title={Impact of Underliner on the Local Deformation of HDPE Geomembranes}, volume={147}, ISSN={["1943-5606"]}, DOI={10.1061/(ASCE)GT.1943-5606.0002533}, abstractNote={AbstractA series of short-term puncture tests is conducted to investigate the deformation behavior of a 0.5-mm-thick high-density polyethylene (HDPE) geomembrane on particulate underliners subjecte...}, number={6}, journal={JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING}, author={Cen, W. J. and Du, X. H. and Wang, H. and Yan, J. and Rahman, M. S.}, year={2021}, month={Jun} }
 @article{cen_du_he_yan_rahman_2020, title={Laboratory testing and numerical modeling of geomembrane electrical leak detection surveys}, volume={27}, ISSN={["1751-7613"]}, DOI={10.1680/jgein.20.00012}, abstractNote={ Laboratory tests were conducted to evaluate the influence of the positions of positive and negative electrodes on the electrical response of a leak in the geomembrane. A numerical evaluation was performed to model the laboratory conditions and to investigate the effect of dipole spacing, excitation voltage, and impoundment resistivity on the leak detection sensitivity. The results of laboratory tests show that leaks cannot be identified when the positive electrode is very close to the leak and the electrical response of a leak in the geomembrane is independent of the position of the negative electrode. The results from the 3D finite element model indicate that leak detection sensitivity improves nonlinearly as the dipole spacing increases, and it tends to be stable after the dipole spacing exceeds 5% of the length of the survey line. The results also indicate that there is an almost linear increase in the leak detection sensitivity with increasing excitation voltage. Substantial improvement was obtained in the leak detection sensitivity for a greater impoundment resistivity. The numerical results indicate that 90% of leaks in a geomembrane liner can be effectively detected and accurately located for the 3D finite element model of a geomembrane lined earth-rock dam. }, number={5}, journal={GEOSYNTHETICS INTERNATIONAL}, author={Cen, W. J. and Du, X. H. and He, H. N. and Yan, J. and Rahman, M. S.}, year={2020}, month={Oct}, pages={490–502} }
 @article{cen_wang_yu_rahman_2020, title={Response of High-Density Polyethylene Geomembrane-Sand Interfaces under Cyclic Shear Loading: Laboratory Investigation}, volume={20}, ISSN={["1943-5622"]}, DOI={10.1061/(ASCE)GM.1943-5622.0001540}, abstractNote={AbstractGeomembranes are thin polymeric sheets used as barriers to liquid or gas intrusion in earth structures due to their low permeability. The mechanical behavior of geomembrane-soil interfaces ...}, number={2}, journal={INTERNATIONAL JOURNAL OF GEOMECHANICS}, author={Cen, W. J. and Wang, H. and Yu, L. and Rahman, M. S.}, year={2020}, month={Feb} }
 @article{cen_luo_yu_shamin rahman_2020, title={Slope Stability Analysis Using Genetic Simulated Annealing Algorithm in Conjunction with Finite Element Method}, volume={24}, ISSN={["1976-3808"]}, DOI={10.1007/s12205-020-2051-5}, number={1}, journal={KSCE JOURNAL OF CIVIL ENGINEERING}, author={Cen, Weijun and Luo, Jiarui and Yu, Jishun and Shamin Rahman, M.}, year={2020}, month={Jan}, pages={30–37} }
 @inproceedings{rafiei_rahman_gabr_2019, title={Computational Geotechnics}, ISBN={9780784482124}, url={http://dx.doi.org/10.1061/9780784482124.019}, DOI={10.1061/9780784482124.019}, abstractNote={Instability of seabed due to wave action may cause serious damages to coastal infrastructure. The wave-induced instantaneous liquefaction near and around a structure, may impact the stability and capacity of foundation elements. The wave-seabed interaction has been mostly studied based on decoupled analysis for the flat or slightly sloping seabed (slope less than five degrees). However, some of marine structures, near shore may be built on (or anchored to) seabed with considerable slopes. In this paper, the response and instability of the sloping seabed supporting a marine structure and subjected to surface waves is evaluated. The scope included developing a numerical model using a fully coupled approach. Biot's equations of the seabed in conjunction with governing equations for other domains (structure and fluid regions) are solved simultaneously using finite element method. The instability of seabed due to wave-induced instantaneous liquefaction around the marine structure is evaluated and the effect of slope on the extent of liquefied zone is examined. The results indicated that seabed response and the extent of liquefied zone near the structure are reduced with increasing steepness of seabed. The effect of various slope steepness and soil parameters on the extent of the liquefied zone is characterized and discussed.}, booktitle={Geo-Congress 2019}, publisher={American Society of Civil Engineers}, author={Rafiei, Amin and Rahman, M. S. and Gabr, M. A.}, year={2019}, month={Mar} }
 @article{cen_luo_zhang_rahman_2018, title={An Enhanced Generalized Plasticity Model for Coarse Granular Material considering Particle Breakage}, volume={2018}, ISSN={["1687-8094"]}, DOI={10.1155/2018/7242936}, abstractNote={In this study, an enhanced constitutive model is developed for coarse granular soil within the framework of generalized plasticity (Pastor, Zienkiewicz, and Chan, 1990). In this model, particle breakage is also considered by introducing the state parameter and the compression index into the plastic modulus, loading vectors, and plastic flow direction vectors of a generalized plasticity model. The calibration of constitutive parameters of the enhanced model is addressed in detail. The numerical simulation of triaxial tests for two types of coarse granular soils under different confining pressures is carried out to illustrate the particle breakage performance of the enhanced model. The good agreement between numerical results and experimental data indicates that the enhanced model can accurately characterize the influence of particle breakage on essential behavior of coarse granular soils.}, journal={ADVANCES IN CIVIL ENGINEERING}, author={Cen, W. J. and Luo, J. R. and Zhang, W. D. and Rahman, M. S.}, year={2018} }
 @article{liu_lei_zheng_feng_rahman_2018, title={Improved Synchronous and Alternate Vacuum Preloading Method for Newly Dredged Fills: Laboratory Model Study}, volume={18}, ISSN={1532-3641 1943-5622}, url={http://dx.doi.org/10.1061/(ASCE)GM.1943-5622.0001220}, DOI={10.1061/(ASCE)GM.1943-5622.0001220}, abstractNote={Cost effectiveness is a major factor in most vacuum preloading projects, considering the significantly reduced time allotted to achieve a relatively high degree of consolidation. However, the shallow base and deep layer of newly dredged fills are always treated separately because the traditional vacuum preloading method can barely make sufficient improvement in the one-time treatment in these weak and complex grounds. Therefore, an improved vacuum preloading method was developed to consolidate newly dredged fills in the Lin Gang Industrial Zone of Tianjin City, China. This improved method consists of three main systems: loading devices, a vacuum preloading system, and a moisture separator technique. By using two loading devices, two lengths of the prefabricated vertical drains (PVDs), and a novel moisture separator, the shallow base and deep layer of the newly dredged fills can be simultaneously processed. The results of water discharge and pore water pressure were measured using three parallel laboratory model tests. The moisture content test and the mercury intrusion porosimetry (MIP) test were conducted along with the vane shear strength test. The testing data shows that the improved vacuum preloading method can substantially improve the bearing capacity of an ultrasoft ground. The multiple vacuum preloading method and the improved synchronous and alternate vacuum preloading method increased the water discharge amount by 8.4% and 27.9%, respectively, over the traditional method. The final dissipation of pore water pressure by the traditional method was one-fifth of that of the improved method because the motion directions of soil particles were changed in the improved method. In addition, the pore size distribution (PSD) of soil changed from a bimodal distribution to a unimodal distribution, as shown by the MIP test results. With similar values in total intrusion volume, porosity, and median pore diameter, the data show that by using this newly improved synchronous and alternate vacuum preloading method, the treatment of ultrasoft dredged fills can be more even, which successfully avoids the common problem of uneven settlement of the ground.}, number={8}, journal={International Journal of Geomechanics}, publisher={American Society of Civil Engineers (ASCE)}, author={Liu, Jingjin and Lei, Huayang and Zheng, Gang and Feng, Shuangxi and Rahman, M. S.}, year={2018}, month={Aug}, pages={04018086} }
 @misc{rahman_ulker_2018, title={Modeling and Computing for Geotechnical Engineering}, ISBN={9780429426186}, url={http://dx.doi.org/10.1201/9780429426186}, DOI={10.1201/9780429426186}, publisher={CRC Press}, author={Rahman, M.S. and Ulker, M.B. Can}, editor={Rahman, M.S. and Can Ülker, M.B.Editors}, year={2018}, month={Sep} }
 @article{zheng_liu_lei_rahman_tan_2017, title={Improvement of very soft ground by a high-efficiency vacuum preloading method: A case study}, volume={35}, ISSN={["1521-0618"]}, DOI={10.1080/1064119x.2016.1215363}, abstractNote={ABSTRACT This paper describes a full-scale test on a very soft clay ground around 70,000 m2, which is conducted in Huizhou of Guangdong Province, China, to present a new method of vacuum preloading method. A novel moisture separator was developed, which can automatically regulate the vacuum pressure variation by changing the volume of the gas inside it. A large quantity of water drained by the proposed moisture separators can be directly used as a surcharge loading, which would shorten the ground improvement time and save costs as well. Three levels of silt-prevention prefabricated vertical drains were used in the treating process to accelerate the consolidation. In addition, the vacuum preloading method also included an effective radial drainage device which would strengthen the dredged soft clay fill in a deep layer. In the in situ test, tens of piezometers and settlement plates were installed to measure the variations of excess pore water pressures and settlement of two stages of observation points at different positions in the ground. The results show that the largest average consolidation settlement was 314.1 cm and made a saving of more than 66% in power consumption compared with traditional method. It demonstrates that this adopted method is an efficient, cost-effective, and environmentally friendly method for improving sites with low bearing capacity and high compressibility soils.}, number={5}, journal={MARINE GEORESOURCES & GEOTECHNOLOGY}, author={Zheng, Gang and Liu, Jingjin and Lei, Huayang and Rahman, M. S. and Tan, Zaikun}, year={2017}, pages={631–642} }
 @article{aghazadeh ardebili_gabr_rahman_2016, title={Uplift Capacity of Plate Anchors in Saturated Clays: Analyses with Different Constitutive Models}, volume={16}, ISSN={1532-3641 1943-5622}, url={http://dx.doi.org/10.1061/(ASCE)GM.1943-5622.0000518}, DOI={10.1061/(asce)gm.1943-5622.0000518}, abstractNote={AbstractEvaluation of the uplift capacity of plate anchors in saturated clay is an important aspect in the design of offshore foundation systems of various structures. In most of the literature reviewed, simple constitutive models such as Tresca or Mohr–Coulomb (MC) have been used in evaluating the plates’ pullout capacity. There exists a need to study the pullout capacity of anchors using other advanced soil models and explore differences in computed behavior. In addition to the MC model, two other constitutive models are used herein to represent the soil behavior. These are Modified Cam-Clay and Soft Soil models. A series of finite-element analyses are performed using the three constitutive models. Undrained effective stress analyses are conducted to study the response of both strip and circular plate anchors in saturated soils. The capacities of plate anchors are assessed through the application of the displacement control approach. The effective stress parameters are correlated with the undrained shea...}, number={2}, journal={International Journal of Geomechanics}, publisher={American Society of Civil Engineers (ASCE)}, author={Aghazadeh Ardebili, Zahra and Gabr, M. A. and Rahman, M. S.}, year={2016}, month={Apr} }
 @article{hassan_rahman_2015, title={Constitutive Models in Simulating Low-Cycle Fatigue and Ratcheting Responses of Elbow}, volume={137}, ISSN={["1528-8978"]}, DOI={10.1115/1.4029069}, abstractNote={As stated in the sister article that the objective of this study was to explore the low-cycle fatigue and ratcheting failure responses of elbow components through experimental and analytical studies. Low-cycle fatigue and ratcheting damage accumulation in piping components may occur under load reversals induced by earthquakes or thermomechanical operations. Ratcheting damage accumulation can cause failure of components through cracking or plastic buckling. Hence, design by analysis of piping components against ratcheting failure will require simulation of this response with reasonable accuracy. In developing a constitutive model that can simulate ratcheting responses of piping components, a systematic set of elbow experiments involving deformation and strain ratcheting were conducted and reported in the sister article. This article will critically evaluate seven different constitutive models against their elbow response simulation capabilities. The widely used bilinear, multilinear, and Chaboche models in ansys are first evaluated. This is followed by evaluation of the modified Chaboche, Ohno–Wang, modified Ohno–Wang, and Abdel Karim–Ohno models. Results from this simulation study are presented to demonstrate that all the seven models can simulate the elbow force response reasonably. The bilinear and multilinear models can simulate the initial elbow diameter change or strain accumulation, but always simulate shakedown during the subsequent cycles when for some of the cases the experimental trends are ratcheting. Advanced constitutive models like Chaboche, modified Chaboche, Ohno–Wang, modified Ohno–Wang, and Abdel Karim–Ohno can simulate many of the elbow ratcheting responses well, but for some of the strain responses, these models simulate negative ratcheting, which is opposite to the experimental trend. Finally, implications of negative ratcheting simulation are discussed and suggestions are made for improving constitutive models ratcheting response simulation.}, number={3}, journal={JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME}, author={Hassan, T. and Rahman, M.}, year={2015}, month={Jun} }
 @article{hassan_rahman_bari_2015, title={Low-Cycle Fatigue and Ratcheting Responses of Elbow Piping Components}, volume={137}, ISSN={["1528-8978"]}, DOI={10.1115/1.4029068}, abstractNote={The objective of this study was to investigate low-cycle fatigue and ratcheting responses of elbows through experimental and analytical studies. Low-cycle fatigue and ratcheting damage accumulation in piping components may occur under repeated reversals of loading induced by earthquake and/or thermomechanical operation. Ratcheting and fatigue damage accumulation can cause failure of piping systems through fatigue cracks or plastic buckling. However, the ratcheting damage induced failures are yet to be understood clearly; consequently, ASME Code design provisions against ratcheting failure continue to be a controversial issue over the last two decades. A systematic set of piping component experimental responses involving ratcheting and a computational tool to simulate these responses will be essential to rationally address the issue. Development of a constitutive model for simulating component ratcheting responses remains to be a challenging problem. In order to develop an experimentally validated constitutive model, a set of elbow experiments was conducted. The loading prescribed in the experiments involved displacement-controlled or force-controlled in-plane cyclic bending with or without internal pressure. Force, displacement, internal pressure, elbow diameter change, and strains at four locations of the elbow specimens were recorded. This article presents and discusses the results from the experimental study. A sister article evaluates seven different constitutive models against simulating these elbow ratcheting and fatigue responses.}, number={3}, journal={JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME}, author={Hassan, T. and Rahman, M. and Bari, S.}, year={2015}, month={Jun} }
 @article{gabr_xiao_rahman_2015, title={Plastic Flow of Sand and Pullout Capacity of Suction Caissons}, volume={141}, ISSN={1090-0241 1943-5606}, url={http://dx.doi.org/10.1061/(ASCE)GT.1943-5606.0001331}, DOI={10.1061/(ASCE)GT.1943-5606.0001331}, abstractNote={A suction caisson has a relatively small length-to-diameter ratio, and the suction-induced seepage forces can liquefy the sand surrounding the caisson, depending on the pullout rate. Houlsby et al. (2005) modeled the seepage forces effect, and its related impact on the effective stresses and the corresponding pullout capacity. However, ignoring potential liquefaction and sand flow that may occur due to the seepage-induced forces can yield an overestimate of pullout capacity as a function of the induced deformation. A Bingham plastic flow model is used to describe the shear stresses as a function of shear strain rate. The general rheological behavior is expressed as when sand flow occurs}, number={8}, journal={Journal of Geotechnical and Geoenvironmental Engineering}, publisher={American Society of Civil Engineers (ASCE)}, author={Gabr, M. A. and Xiao, J. and Rahman, M. S.}, year={2015}, month={Aug}, pages={02815002} }
 @inproceedings{aghazadeh_rahman_gabr_2014, title={Evaluation of plate anchors capacity in saturated soils using different constitutive models}, DOI={10.1115/omae2014-24226}, abstractNote={Evaluation of the uplift capacity of plate anchors in saturated clay is an important aspect in offshore anchoring of various structures. In most of the literature reviewed, a constitutive model such as Tresca or Mohr-Coulomb has been used in analyses. There exists a need to study the anchors’ pull out capacity using other advanced soil models and discern differences in results.}, booktitle={33rd International Conference on Ocean, Offshore and Arctic Engineering, 2014, vol 3}, author={Aghazadeh, Z. and Rahman, M. S. and Gabr, Mohammed}, year={2014} }
 @inproceedings{xiao_gabr_rahman_2014, title={Preliminary Structural Design of OCAES Vessel}, DOI={10.1115/omae2014-24053}, abstractNote={A vessel for Offshore Compressed Air Energy Storage (OCAES) is being considered as a part of the emerging technology to store intermittently generated energy from offshore renewable sources. The basic idea is to submerge the storage vessel into the ocean at a large water depth, convert the energy into compressed air, store it with using the hydrostatic water pressure to balance the compressed air pressure without requiring the storage vessels to resist high internal air pressure. An additional advantage is that the interface of air and water acts as a piston to maintain the air pressure level.}, booktitle={Volume 9B: Ocean Renewable Energy}, publisher={ASME International}, author={Xiao, Jinfu and Gabr, M. and Rahman, M. S.}, year={2014}, month={Jun} }
 @article{mashrei_seracino_rahman_2013, title={Application of artificial neural networks to predict the bond strength of FRP-to-concrete joints}, volume={40}, ISSN={["1879-0526"]}, DOI={10.1016/j.conbuildmat.2012.11.109}, abstractNote={A Back-Propagation Neural Network (BPNN) model for predicting the bond strength of FRP-to-concrete joints is proposed. Published single-lap shear test specimens were used to predict the bond strength of externally bonded FRP systems adhered to concrete prisms. A database of one hundred and fifty experimental data points from several sources was used for training and testing the BPNN. The data used in the BPNN are arranged in a format of six input parameters including: width of concrete prism; concrete cylinder compressive strength; FRP thickness; bond length; bond width (i.e. FRP width); and FRP modulus of elasticity. The one corresponding output parameter is the bond strength. A parametric study was carried out using BPNN to study the influence of each parameter on the bond strength and to compare results with common existing analytical models. The results of this study indicate that the BPNN provides an efficient alternative method for predicting the bond strength of FRP-to-concrete joints when compared to experimental results and those from existing analytical models.}, journal={CONSTRUCTION AND BUILDING MATERIALS}, author={Mashrei, Mohammed A. and Seracino, R. and Rahman, M. S.}, year={2013}, month={Mar}, pages={812–821} }
 @article{ulker_rahman_guddati_2011, title={Breaking wave-induced response and instability of seabed around caisson breakwater}, volume={36}, ISSN={0363-9061}, url={http://dx.doi.org/10.1002/nag.1073}, DOI={10.1002/nag.1073}, abstractNote={SUMMARY}, number={3}, journal={International Journal for Numerical and Analytical Methods in Geomechanics}, publisher={Wiley}, author={Ulker, M. B. C. and Rahman, M. S. and Guddati, M. N.}, year={2011}, month={Aug}, pages={362–390} }
 @article{mashrei_abdulrazzaq_abdalla_rahman_2010, title={Neural networks model and adaptive neuro-fuzzy inference system for predicting the moment capacity of ferrocement members}, volume={32}, ISSN={["0141-0296"]}, DOI={10.1016/j.engstruct.2010.02.024}, abstractNote={In this paper, back-propagation neural networks (BPNN) and an adaptive neuro-fuzzy inference system (ANFIS) models developed to predict the moment capacity of ferrocement members are presented. A database from tests on ferrocement members is developed from the review of literature and some new tests. The selected input variables include the width and the depth of specimens, cube compressive strength of mortar, and tensile strength and volume fraction of wire mesh. A parametric study is carried out using BPNN to study the influence of each parameter affecting the moment capacity of the ferrocement member. The results of this study indicate that both BPNN and ANFIS provide good predictions which are better than those from other available methods. These models can serve as reliable and simple predictive tools for the prediction of moment capacity of ferrocement members.}, number={6}, journal={ENGINEERING STRUCTURES}, author={Mashrei, Mohammed A. and Abdulrazzaq, Nabeel and Abdalla, Turki Y. and Rahman, M. S.}, year={2010}, month={Jun}, pages={1723–1734} }
 @inproceedings{ulker_rahman_guddati_2010, title={Standing wave-induced dynamic response and instability of seabed under a caisson breakwater}, DOI={10.1115/omae2010-20524}, abstractNote={The wave-induced dynamic response and instability of the porous seabed and the rubble mound foundation under a composite caisson-type breakwater is studied using finite elements. In this study the focus is on the effect of inertial terms on the dynamic response and instability of the foundation material underneath the breakwater. It is assumed that a fully standing wave condition occurs in front of the caisson under the cyclic wave action and the dynamic response of the seabed and rubble mound is presented in terms of pore pressures and stresses induced around the breakwater. A complete formulation of the fully dynamic (FD) response requires inclusion of the inertial terms associated with both the motion of solid skeleton and that of pore fluid. However, partly dynamic (PD) and quasi-static (QS) idealizations are also possible. The objective of this study is to investigate the standing wave induced dynamic response and instability of seabed-rubble-breakwater system.}, booktitle={Proceedings of the ASME 29th International Conference on Ocean, Offshore and Arctic Engineering, 2010,  vol 1}, author={Ulker, M. B. C. and Rahman, M. S. and Guddati, M. N.}, year={2010}, pages={737–746} }
 @article{ulker_rahman_guddati_2010, title={Wave-induced dynamic response and instability of seabed around caisson breakwater}, volume={37}, ISSN={["0029-8018"]}, DOI={10.1016/j.oceaneng.2010.09.004}, abstractNote={In this study, standing wave-induced dynamic response and instability of seabed around a caisson breakwater are investigated. A seabed-rubble-caisson breakwater system is modeled using finite elements. The dynamic response of the porous seabed-rubble foundation is assumed to be governed by the Biot’s equations of coupled flow and deformation. Three possible formulations (fully dynamic, partly dynamic and quasi-static) are considered with respect to the inclusion of inertial terms associated with the motion of fluid and solids. The response is presented in terms of stress and pore pressure distributions at three locations underneath the breakwater. The instability of seabed and rubble mound due to instantaneous liquefaction is also studied. The effects of seabed and wave parameters and the effect of inertial terms on the standing wave-induced dynamic response and instability of the system are investigated through a set of parametric studies. Analyses show that quasi-static and partly dynamic formulations yield similar results while the fully dynamic formulation provides different response. The results from different formulations suggest the use of all inertial terms (fully dynamic formulation), providing the most complete solution and the least conservative response.}, number={17-18}, journal={OCEAN ENGINEERING}, author={Ulker, M. B. C. and Rahman, M. S. and Guddati, M. N.}, year={2010}, month={Dec}, pages={1522–1545} }
 @article{ulker_rahman_2009, title={Response of saturated and nearly saturated porous media: Different formulations and their applicability}, volume={33}, ISSN={["1096-9853"]}, DOI={10.1002/nag.739}, abstractNote={Abstract}, number={5}, journal={INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS}, author={Ulker, M. B. C. and Rahman, M. S.}, year={2009}, month={Apr}, pages={633–664} }
 @article{ulker_rahman_jeng_2009, title={Wave-induced response of seabed: Various formulations and their applicability}, volume={31}, ISSN={["1879-1549"]}, DOI={10.1016/j.apor.2009.03.003}, abstractNote={In this study, a set of generalized analytical solutions are developed for the wave-induced response of a saturated porous seabed under plane strain condition. When considering the water waves originating in deep water and travelling towards the shore, their velocities, lengths and heights vary. Depending on the characteristics of the wave and the properties of the seabed, different formulations (fully dynamic, partly dynamic, quasi-static) for the wave-induced response of the seabed are possible. The solutions for the response with these formulations are established in terms of non-dimensional parameters. The results are presented in terms of pore pressure, shear stress and vertical effective stress distributions within the seabed. For typical values of wave period and seabed permeability, the regions of applicability of the three formulations are identified and plotted in parametric spaces. With given wave and seabed characteristics, these regions provide quick identification of the appropriate formulation for an adequate evaluation of the wave-induced seabed response.}, number={1}, journal={APPLIED OCEAN RESEARCH}, author={Ulker, M. B. C. and Rahman, M. S. and Jeng, D. -S.}, year={2009}, month={Feb}, pages={12–24} }
 @article{xu_rahman_2008, title={Finite element analyses of layered visco-elastic system under vertical circular loading}, volume={32}, ISSN={["0363-9061"]}, DOI={10.1002/nag.650}, abstractNote={Abstract}, number={8}, journal={INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS}, author={Xu, Q. and Rahman, M. S.}, year={2008}, month={Jun}, pages={897–913} }
 @article{ulker_rahman_zhen_mirmiran_2008, title={Traffic barriers under vehicular impact: From computer simulation to design guidelines}, volume={23}, ISSN={["1093-9687"]}, DOI={10.1111/j.1467-8667.2008.00552.x}, abstractNote={Abstract:   In this study, the problem of vehicular impact on a portable concrete barrier (PCB) is investigated. An available crash test is modeled and the impact response was simulated through a finite element (FE) model. On the basis of insight gained through this detailed FE analysis, a simpler rigid body model is then used to perform a comprehensive study of the barrier response under vehicular impact. The results from FE simulation and the rigid body model are found to be consistent with each other and in good agreement with the full‐scale crash test. On the basis of results from a series of simpler analyses, a set of charts for assessing the barrier displacement and related variables are developed for the purpose of design. }, number={6}, journal={COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING}, author={Ulker, M. B. C. and Rahman, M. S. and Zhen, R. and Mirmiran, A.}, year={2008}, month={Aug}, pages={465–480} }
 @article{jeon_rahman_2007, title={A neural network model for prediction of pile setup}, ISSN={["2169-4052"]}, DOI={10.3141/2004-02}, abstractNote={ The time-dependent increase in pile capacity after its driving may be significant. A reliable prediction of this increase (setup) may lead to a significant saving in pile design. A neural network model to predict pile setup was developed. A database derived from field tests reported in the literature showing setup of driven piles was compiled, with six variables selected as input parameters: soil type, pile type, pile diameter, pile length, time after pile installation, and initial effective stress at tip. Ultimate pile capacity at beginning of restrike (QBOR) is the sum of pile capacity (QEOD) at end of drive and increased in capacity (ΔQBOR) caused by setup, which in this study is predicted by a backpropagation neural network. The results demonstrate that the neural network model provides a better prediction than predictions by the available empirical methods. A neural network model can serve as a reliable tool for the prediction of pile setup, and further training with additional data will lead to additional improvement in the quality of prediction. }, number={2004}, journal={TRANSPORTATION RESEARCH RECORD}, author={Jeon, Jongkoo and Rahman, M. Shamimur}, year={2007}, pages={12–19} }
 @inproceedings{sarica_rahman_2006, title={Analysis of Ground Motion: A Comparison of Some Available Methods}, ISBN={9780784408032}, url={http://dx.doi.org/10.1061/40803(187)200}, DOI={10.1061/40803(187)200}, abstractNote={The earthquake induced ground motions are transient and nonstationary. Both their amplitude and frequency content vary with time. Analysis and design of structures need to consider these nonstationary characteristics. In studying time series, several methods have been developed and used by researchers and practitioners. Here, a comparison of Fourier Transform (FT), Short Time Fourier Transform (STFT), Hilbert Huang Transform (HHT), and Wavelet Transform (WT) are presented.}, booktitle={GeoCongress 2006}, publisher={American Society of Civil Engineers}, author={Sarica, R. Z. and Rahman, M. S.}, year={2006}, month={Feb} }
 @article{rahman_islam_yamada_2006, title={Spectroscopic investigation of strain induced by compositional variation in bulk InxGa1–xAs crystal grown by MCZM method}, volume={41}, ISSN={0232-1300 1521-4079}, url={http://dx.doi.org/10.1002/crat.200510999}, DOI={10.1002/crat.200510999}, abstractNote={Raman scattering (RS), photoluminescence (PL) and energy dispersive X‐ray (EDX) experiments have been carried out to investigate residual strain and hence to understand breakage issue in bulk Inx Ga1–x As crystal grown by multi component zone melting (MCZM) method. It is found from a comparison that there is a large discrepancy among the RS, PL and EDX results due to the strain induced by compositional variation in the crystal. The strain induced changes in TOGaAs and PL peak positions are found to be 4.04 cm–1 and 0.097 eV, respectively, for the variation of composition from 0.06 to 0.29 from the seed‐end to the tail‐end of the crystal. By assuming a simple one‐dimensional strain distribution, the strain value corresponding to 4.04 cm–1/ 0.097 eV can be obtained of the order of 10–2, which is large enough for understanding the breakage issue in the crystal investigated here. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)}, number={4}, journal={Crystal Research and Technology}, publisher={Wiley}, author={Rahman, M. S. and Islam, M. R. and Yamada, M.}, year={2006}, month={Apr}, pages={358–363} }
 @inproceedings{kim_rahman_gabr_sarica_hossain_2005, title={Reliability Based Calibration of Resistance Factors for Axial Capacity of Driven Piles}, volume={132}, ISBN={9780784407783}, url={http://dx.doi.org/10.1061/40778(157)12}, DOI={10.1061/40778(157)12}, abstractNote={Resistance factors were calibrated using the framework of reliability theory for the Load and Resistance Factor Design (LRFD) of driven pile’s axial capacity in North Carolina utilizing pile load test data available from the North Carolina Department of Transportation (NCDOT). A total of 140 Pile Driving Analyzer (PDA) data and 35 static load test data were compiled and grouped into different design categories based on four pile types and two geologic regions. Resistance statistics were evaluated for each design category in terms of bias factors. Reliability analysis of the current NCDOT practice of pile foundation design was performed to evaluate the level o f safety and to select the target reliability indices. Resistance factor calibration was performed for the three methods of static pile capacity analysis commonly used in the NCDOT: the Vesic (1977), the Nordlund (1963), and the Meyerhof (1976) methods. Two types of First Order Reliability Methods (Mean Value First Order Second Moment method and Advanced First Order Second Moment method) were used for the reliability analysis and the calibration of the resistance factors. The calibrated resistance factor s varied significantly for the different pile types and geologic regions. The advanced first order second moment method resulted in larger resistance factors than the mean value first order second moment method. Recommended resistance factors are presented for the three methods of static pile capacity analysis and for seven different design categories of pile types and geologic regions.}, booktitle={Advances in Deep Foundations}, publisher={American Society of Civil Engineers}, author={Kim, K. J. and Rahman, M. S. and Gabr, M. A. and Sarica, R. Z. and Hossain, M. S.}, year={2005}, month={Oct}, pages={735–746} }
 @article{rahman_wang_2002, title={Fuzzy neural network models for liquefaction prediction}, volume={22}, ISSN={["0267-7261"]}, DOI={10.1016/S0267-7261(02)00059-3}, abstractNote={Integrated fuzzy neural network models are developed for the assessment of liquefaction potential of a site. The models are trained with large databases of liquefaction case histories. A two-stage training algorithm is used to develop a fuzzy neural network model. In the preliminary training stage, the training case histories are used to determine initial network parameters. In the final training stage, the training case histories are processed one by one to develop membership functions for the network parameters. During the testing phase, input variables are described in linguistic terms such as 'high' and 'low'. The prediction is made in terms of a liquefaction index representing the degree of liquefaction described in fuzzy terms such as 'highly likely', 'likely', or 'unlikely'. The results from the model are compared with actual field observations and misclassified cases are identified. The models are found to have good predictive ability and are expected to be very useful for a preliminary evaluation of liquefaction potential of a site for which the input parameters are not well defined.}, number={8}, journal={SOIL DYNAMICS AND EARTHQUAKE ENGINEERING}, author={Rahman, MS and Wang, J}, year={2002}, month={Sep}, pages={685–694} }
 @article{rahman_wang_deng_carter_2001, title={A neural network model for the uplift capacity of suction caissons}, volume={28}, ISSN={["0266-352X"]}, DOI={10.1016/S0266-352X(00)00033-1}, abstractNote={Suction caissons are frequently used for the anchorage of large compliant offshore structures. The uplift capacity of the suction caissons is a critical issue in these applications, and reliable methods of predicting the capacity are required in order to produce effective designs. In this paper a back-propagation neural network model is developed to predict the uplift capacity of suction foundations. A database containing the results from a number of model and centrifuge tests is used. The results of this study indicate that the neural network model serves as a reliable and simple predictive tool for the uplift capacity of suction caissons. As more data becomes available, the model itself can be improved to make more accurate capacity prediction for a wider range of load and site conditions. The neural network predictions are also compared with finite element based predictions.}, number={4}, journal={COMPUTERS AND GEOTECHNICS}, author={Rahman, MS and Wang, J and Deng, W and Carter, JP}, year={2001}, pages={269–287} }
 @article{jeng_rahman_2000, title={Effective stresses in a porous seabed of finite thickness: inertia effects}, volume={37}, ISSN={["0008-3674"]}, DOI={10.1139/cgj-37-6-1383}, abstractNote={The evaluation of wave-induced pore pressure and effective stresses is an important factor in the design of offshore installations. However, to simplify a complicated problem, most previous investigations have ignored the effects of inertia forces. This paper presents a new semi-analytical solution to the equations governing the wave-induced seabed response, including inertia terms for the whole problem. The numerical results show that the inertia forces cannot always be ignored. The relative difference between the present solution (with inertia items) and the previous solution (without inertia items) may reach 17% of po under certain combinations of wave and soil conditions. Key words: inertia force, pore pressure, effective stresses.}, number={6}, journal={CANADIAN GEOTECHNICAL JOURNAL}, author={Jeng, DS and Rahman, MS}, year={2000}, month={Dec}, pages={1383–1392} }
 @article{wang_rahman_1999, title={A neural network model for liquefaction-induced horizontal ground displacement}, volume={18}, ISSN={["0267-7261"]}, DOI={10.1016/S0267-7261(99)00027-5}, abstractNote={The horizontal ground displacement generated by seismically induced liquefaction is known to produce significant damage to engineered structures. A backpropagation neural network model is developed to predict the horizontal ground displacements. A large database containing the case histories of lateral spreads observed in eight major earthquakes is used. The results of this study indicate that the neural network model serves as a reliable and simple predictive tool for the amount of horizontal ground displacement. As more data become available, the model itself can be improved to make more accurate displacement prediction for a wider range of earthquake and site conditions.}, number={8}, journal={SOIL DYNAMICS AND EARTHQUAKE ENGINEERING}, author={Wang, J and Rahman, MS}, year={1999}, month={Dec}, pages={555–568} }
 @article{rahman_yeh_1999, title={Variability of seismic response of soils using stochastic finite element method}, volume={18}, ISSN={["0267-7261"]}, DOI={10.1016/S0267-7261(98)00031-1}, abstractNote={The evaluation of seismic response of soil sites constitutes an important problem with respect to groundmotion amplification and soil instability because of liquefaction. The base motion generated during earthquake is a random process. In addition, the soil sites are usually homogenous with randomly varying characteristics. The uncertainties associated with the input motion and site characteristics may lead to a wide range of variability of the site response. In this paper, a Monte-Carlo based stochastic finite element method is used to study the variability of seismic response.}, number={3}, journal={SOIL DYNAMICS AND EARTHQUAKE ENGINEERING}, author={Rahman, MS and Yeh, CH}, year={1999}, month={Apr}, pages={229–245} }
 @inbook{muhanna_rahman_lambe_1998, title={Model for resilient modulus and permanent strain of subgrade soils}, ISBN={0309064635}, DOI={10.3141/1619-10}, abstractNote={ The resilient modulus and cumulative permanent strain of subgrade soils under anticipated repeated loading are important considerations for the design of a pavement against fatigue and rutting failures. A simple model was developed to evaluate the resilient modulus and accumulated permanent strain of cohesive subgrade soils under repeated loads. The empirical model was derived from the observed behavior of an A-6 cohesive soil. The model was tested against an A-5 soil. The proposed model was found to predict adequately the resilient modulus and the accumulated plastic strain for all A-6 and A-5 specimens with 90 percent confidence intervals of 0.61 and 1.4, and 0.66 and 1.39, respectively. }, number={1619}, booktitle={Testing of conventional and unconventional aggregates and soils}, publisher={Washington, DC: Transportation Research Board}, author={Muhanna, A. S. and Rahman, M. S. and Lambe, P. C.}, year={1998}, pages={85–93} }
 @article{yeh_rahman_1998, title={Stochastic finite element methods for the seismic response of soils}, volume={22}, DOI={10.1002/(SICI)1096-9853(1998100)22:10<819::AID-NAG943>3.3.CO;2-9}, abstractNote={Some of the available stochastic finite element methods are adapted and evaluated for the analyses of response of soils with uncertain properties subjected to earthquake induced random ground motion. In this study, the dynamic response of a soil mass, with finite element discretization, is formulated in the frequency domain. The spectral density function of the response variables are obtained from which the evaluation of the root-mean-squared and the most probable extreme values of the response are made. The material non-linearities are incorporated by using strain compatible moduli and damping of soils using an equivalent linear model for stress–strain behaviour of soils and an iterative solution of the response. The spatial variability of the shear modulus is described through a random field model and the earthquake included motion is treated as a stochastic process. The available formulations of direct Monte-Carlo simulation, first-order perturbation method, a spectral decomposition method with Neumann expansion and a spectral decomposition method with Polynomial Chaos are used to develop stochastic finite element analyses of the seismic response of soils. The numerical results from these approaches are compared with respect to their accuracy and computational efficiency. © 1998 John Wiley & Sons Ltd.}, number={10}, journal={International Journal for Numerical and Analytical Methods in Geomechanics}, author={Yeh, C. H. and Rahman, M. S.}, year={1998}, pages={819–850} }
 @inproceedings{rahman_el-zahaby_1997, title={Inclusion of fuzzy variables in geotechnical risk analysis}, volume={9}, number={1997}, booktitle={Computer methods and advances in geomechanics: Proceedings of the Ninth International Conference of the Association for Computer Methods and Advances in Geomechnics: Wuhan, China, 2-7 November, 1997}, author={Rahman, M. S. and El-Zahaby, K. E.}, year={1997}, pages={567–572} }
 @article{rahman_1997, title={Instability and movements of ocean floor sediments: a review}, volume={7}, number={3}, journal={International Journal of Offshore and Polar Engineering}, author={Rahman, M. S.}, year={1997}, pages={220–225} }