Anisotropic Permeability Evaluation of Pusan Clays at the New Pusan Port

M. Suneel,Chung, S.G.,Ganapathi Rao 東亞大學校 建設技術硏究所 2005 硏究論文集 Vol.28 No.2

Large reclamation projects have been carried out in the western marginal area of the Nakdong River Estuary where are located at Busan city and its vicinity, South Korea, since late 1990s. In the area studied clay deposits are usually thick, varying from 20m to 70m in thickness. The present paper concerns a comparative analysis of the possible methods for estimating permeability at the New Pusan port. CRS consolidation tests with radial and vertical drainage, oedometer and some permeability measurement tests were conducted to provide the consolidation characteristics. A piezocone was used to measure the pore water pressure dissipation characteristics in the field, and the corresponding horizontal coefficients of consolidation were estimated based on established theory.Possible influence of artesian pressure from the underlying sand layer on to the pore pressure profile of the clay layer was also investigated using piezometer.

Experimental Evaluation of Wheeler's Hardening Model for Pusan Clays

M. Suneel,Chung, S.G.,K.G. Rao 東亞大學校 建設技術硏究所 2005 硏究論文集 Vol.28 No.2

The present paper adopts Wheeler's model to evaluate its application to Pusan clays. A program of triaxial and consolidation tests on samples of Pusan clays at Yangsan, Korea was undertaken to investigate the applicability of the model. The model parameters are evaluated by describing the initial state of the soil. Model predictions are shown to be qualitatively consistent with experimental observations, but refinement seems to be required to have much better agreement between experimental results and model predictions.

Ultimate Strength of Orthogonal Stiffened Plates Subjected to Axial and Lateral Loads

M. Suneel Kumar,C. Lavana Kumar,P. Alagusundaramoorthy,R. Sundaravadivelu 대한토목학회 2010 KSCE Journal of Civil Engineering Vol.14 No.2

Orthogonal stiffened plates present in the ship deck are subjected to axial compression due to hogging and sagging bending moments and, lateral load due to cargo load. The main objective of this investigation is to determine the ultimate load carrying capacity and study the interactive behaviour of orthogonal stiffened plates under axial and lateral loads. Tests were conducted on six stiffened plates with plate slenderness ratios of 80 and 64, and corresponding column slenderness ratios of 24 and 26. Hydraulic jacks and inflatable air balloon with load control mechanism were fabricated to apply axial and lateral loads on the test specimens respectively. All the specimens were tested up to ultimate load and the mode of failure was determined based on the initial yielding observed in the plate and/or stiffener. Nonlinear finite element analysis of test specimens was performed using the general purpose FE software ANSYS®. Both material and geometric nonlinearities were considered in the FE analysis of test specimens. The ultimate loads obtained from the finite element analysis were compared with experimental data and found to be satisfactory. It was also observed that the mode of failure obtained from finite element analysis is similar as observed from experiments. It was concluded that the increase in lateral load beyond two thirds of ultimate lateral load significantly reduces the axial ultimate load carrying capacity of stiffened panels. The interactive effect of stiffened plates subjected to combined action of axial and lateral loads is determined as nonlinear.

Consolidation Characteristics of Pusan Clays by Constant Rate of Strain and Conventional Oedometer Tests

E. Ninjgarav,Chung, S.G.,M. Suneel,Ganapathi Rao,Kim, G.J. 東亞大學校 建設技術硏究所 2005 硏究論文集 Vol.28 No.2

Large reclamation projects for a new Busan Port have been carried out in the western marginal area of the Nakdong River Estuary where are located at Busan city and its vicinity, south Korea, since the middle of 1990s. In the area studied clay deposits are usually thick, varying from 20m to 70m in thickness. The consolidation behaviour of Pusan clays in investigated by means of constant rate of strain consolidation tests with vertical and horizontal drainage conditions, comparing with those of conventional oedometer tests. For this, a sophisticated sampling technique was adopted for the site, as well as the preparation of specimens. As the results of tests, the sample quality was evaluated using the results of the consolidation testing. The effects of strain rate on consolidation properties such as apparent preconsolidation pressure, compression index and coefficient of consolidation are evaluated for the kinds of the tests. Moreover, the anisotropy of permeability and coefficients of consolidation were also compared with depth. Particularly the consolidation characteristics were presented with depositional environment at the site.

Consolidation and Permeability Properties of Pusan Clay at the Pusan New Port

K.Ganapathi Rao,Chung, S.G.,M. Suneel 東亞大學校 建設技術硏究所 2005 硏究論文集 Vol.28 No.2

Large reclamation projects have been carried out in the western marginal area of the Nakdong River Estuary where are located at Busan city and its vicinity, South Korea, since late 1990s. In the area studied clay deposits are unusually thick, varying from 20m to 70m in thickness. The consolidation and permeability characteristics of these clays were investigated by laboratory tests. The coefficients of consolidation and permeability of the clays in the vertical and horizontal directions were investigated by oedometer, constant rate of strain (CRS) and CRS tests with outward radial drainage. It is found from the test results that theseclays have a specific stress-strain relationship depending on the strain rate history and depositional environment, as well as a variation of permeability anisotropy during consolidation.

Geological and Geotechnical Characteristics of Marine Clay in Busan New Port

Chung, S.G,E. Ninjgarav,M. Suneel,K.Ganapathi Rao,Kim, G.J. 東亞大學校 建設技術硏究所 2005 硏究論文集 Vol.28 No.2

Since early 1990s reclamation projects for Busan and its vicinity in Nakdong River plain have been performed for industrial and residential complexes. As well it has started to build a new port (Busan Newport) with increase in overloads of Busan port since late 1990s. In the area the sedimentary deposit is composed of soft clay of about 30m thick, thin sand layer of 3-4m thick, hard clayey soil, and then basal conglomerates and sandy sediments, total thickness of which is about 70m at maximum under seawater. For the huge project many contract companies have simultaneously performed geotechnical investigations to get design parameters. Based on the harmful experiences gained by the previous projects, it was also required to pay careful attention to sampling and laboratory and field tests for theproject. Nevertheless the results of laboratory tests were so scattered and then resulted in difficulty to evaluate the design parameters. Existing data has been reviewed to evaluate the validity or cause of their variation. In addition geological study, sampling and soil tests have been carefully carried out at a few locations. Using the results the clay would be effectively characterized for depositional environment and its relation to soil properties.

RADAR level measurement in Joule heated ceramic melter: A novel technique

Suneel, G.,Mahashabde, Mukesh,Borkotoky, Ritusmita,Sharma, Nitin Kumar,Pradeep, M.P.,Gayen, J.K.,Pimparkar, H.R.,Ravi, K.V. Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.4

The current study relates to RADAR (RAdio Detection and Ranging) application for level measurement of vitrified radioactive liquid nuclear waste. The vitrification of radioactive liquid waste is carried out in special equipment called 'Melters'. The study is directed towards the design and frequency modulation used in the level measurement of vitrified waste. More specifically, the RADAR design and frequency used for level measurement in a melter. This level measurement technique can also be used for dynamic vitrification process and can be used to measure the level variations without using any external medium/material and using only electromagnetic waves. Also, this technique is durable and accurate even under the high radioactive environment present inside the melter.

Performance Comparison of Sliding Mode Observers for Back EMFs based Speed Estimation in PMSM

Suneel K. Kommuri,Jagat J. Rath,Kalyana C. Veluvolu,M. Defoort,S. Tatinati 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10

This paper proposes a second-order high-speed sliding mode (SHSM) observer and compares the performance with the recent higher-order sliding mode (HOSM) observer for the problem of sensorless speed estimation in the permanent magnet synchronous motor (PMSM). In which, a sigmoid function is substituted for the signum function with a variable boundary layer. A SHSM observer is proposed to provide the estimation of back electro motive forces (EMFs) that are treated as unknown inputs in the PMSM model. An accurate speed estimate of PMSM can be algebraically computed with the estimated back EMFs. The chattering phenomenon, that is commonly found in the sliding mode observers is well-reduced by replacing signum function with the sigmoid function, in comparison to the HOSM observer. Simulation results show the effectiveness of the proposed SHSM speed estimation method in comparison to the earlier HOSM observer in terms of good accuracy and chattering phenomenon.

Robust Fault-Tolerant Cruise Control of Electric Vehicles based on Second-order Sliding Mode Observer

Suneel K. Kommuri,Jagat J. Rath,Kalyana C. Veluvolu,M. Defoort 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

This paper presents fault-tolerant cruise control of an electric vehicle based on the permanent magnet synchronous motor (PMSM). A higher order sliding mode (HOSM) observer is designed to estimate the unknown back electro motive forces (EMFs) in the plant dynamics. A finite-time smooth estimation without low-pass filtering is obtained and the chattering phenomenon is eliminated. With the estimated back EMFs, an accurate speed estimate of PMSM can be algebraically computed. The estimated speed is provided as a feedback whenever fault occurs in the measurement speed. The corresponding torque output drives the electric vehicle (train, car) to maintain the vehicle speed to a desired vehicle speed reference. Simulations in a high fidelity CarSim confirm the validity of the overall approach.

Higher-Order Sliding Mode Observer for Speed and Position Estimation in PMSM

Kommuri, Suneel K.,Veluvolu, Kalyana C.,Defoort, M.,Soh, Yeng C. Hindawi Limited 2014 Mathematical problems in engineering Vol.2014 No.-

<P>This paper presents a speed and position estimation method for the permanent magnet synchronous motor (PMSM) based on higher-order sliding mode (HOSM) observer. The back electromotive forces (EMFs) in the PMSM are treated as unknown inputs and are estimated with the HOSM observer without the need of low-pass filter and phase compensation modules. With the estimation of back EMFs, an accurate estimation of speed and rotor position can be obtained. Further, the proposed method completely eliminates chattering. Experimental results with a 26 W three-phase PMSM demonstrate the effectiveness of the proposed method.</P>