Multi-Component Machine Monitoring and Fault Diagnosis Using Bling Source Separation and Advanced Vibration Analysis

Bearing Capacity of Rectangular Footing Resting Over Geogrid Reinforced Sand Under Eccentric Loading - 2014 -

Experimental and numerical investigations of higher mode effects on seismic response of reinforced concrete shear walls

Ghorbanirenani, Iman (2010) 

The Analysis of a Deep Excavation in a Gassy Soil

Authors:	Mabrouk, AHMED
Files in This Item: File mirror Size Format The Analysis of a Deep Excavation in a Gassy Soil.pdf Link 9 MB Adobe PDF
Keywords:	Hydrofracturing Numerical forensic analysis Finite element Excavation Gassy soil
Issue Date:	28-Aug-2012
Series/Report no.:	Canadian theses
Abstract:	The study presents a numerical analysis of series of unanticipated events that took place upon the excavation of a landfill in a deep deposit of clayey soil in southwestern Ontario, Canada. During the excavation of a landfill cell to be used for waste disposal, unexpected lateral slope movements were observed followed by gas and water venting in several locations (while the excavation in low permeability clayey till was about 14m above the underlying aquifer). The clayey till is known to be underlain by permeable, natural gas bearing rock, and gas has been diffusing through the clayey deposit over about the last 13,000-15,000 years. Preliminary 2D and 3D elasto-plastic effective stress analyses using conventional soil mechanics –similar to what was used in design- are used to capture the general behaviour of the excavation. However, the analyses revealed the need for model modification to account for other governing factors (gassy soil and hydrofracturing) to be able to explain the mechanism that might have lead to the evolution of gas vents and upward water flow through the thick shale aquitard. The clayey deposit contains silty sand lenses at different elevations. The upward diffusion of methane and chloride from the bedrock aquifer through the clay till is modelled and the potential for chloride migration contributing to the exsolution of methane due to reduction in methane solubility is discussed. Two approaches to modelling the lenses are examined where gas exsolution either occurs prior to or during the excavation. The FE model is modified to account for hydrofacturing and gassy soil behaviour (for sand lenses). 2D and 3D forensic modelling studies are presented examining the potential causes for the unanticipated movements and the gas and water venting observed during the excavation. The model investigates the role of presence of gassy sand lenses and of the presence of a discontinuous weak sandy clayey silt layer between the bedrock and the low permeability till on the hydrofracturing path and gas venting. Finally, a parametric study is conducted to examine the effect of different parameters on the soil behaviour when excavated. Recommendations regarding further excavations within the same soil deposit are presented.

Heated Biofilm Growth in a Planar Fracture for Reduction of Hydraulic Aperture

Authors:	GRELL, STEPHANIE LOUISE
Files in This Item: File Description Size Format Heated Biofilm Growth in a Planar Fracture for Reduction of Hydraulic Aperture.pdf 3.12 MB Adobe PDF
Keywords:	Hydrogeology Bioremediation Fractured Bedrock
Issue Date:	10-Aug-2011
Series/Report no.:	Canadian theses
Abstract:	The objective of this study was to examine the effect of heat on the growth of a biofilm in a parallel glass plate fracture table. Groundwater was collected from a limestone aquifer and amended with a nutrient mixture to stimulate the indigenous microbial population. The amended water was heated to approximately 30oC in an upgradient reservoir attached to the fracture table and recirculated through the 2-m long, 0.6-m wide, parallel glass plate fracture having an approximate fracture aperture of 2000 μm. The fracture was maintained at approximately 10oC to simulate natural in situ groundwater temperature and the upgradient reservoir maintained at 30oC. Geochemical parameters and bacterial counts were measured regularly throughout the biostimulation to monitor biofilm growth in the fracture. Hydraulic tests and tracer experiments completed before and after the biostimulation were used as the primary indicators of the successful bioclogging of the fracture. Geochemical parameters measured throughout the trial revealed an increasingly reducing environment capable of supporting the development of a diverse biofilm. Direct and indirect bacterial counts revealed the dominant bacteria within the system included common groundwater bacteria pseudonomads, enteric, and slime-forming bacteria. Heterotrophic bacteria were also present in significant concentrations. Visible clusters of biofilm were observed on Day 2 of the trial with a fully-connected biofilm observed by Day 7. The biofilm impacted the groundwater flow through the fracture resulting in an approximately 2.75-hour delay in the tracer’s breakthrough during the tracer experiment completed on Day 13 of the trial compared to an experiment conducted during the initial stages of biofilm development. Based on the results of the tracer experiment, the biofilm growth reduced the velocity of the groundwater by 9.8%, the fracture aperture by 37.8%, and increased the bulk dispersivity to 50mm. Recommendations for future work include the application of heated biostimulation at the field scale in a well-characterized, isolated fracture.

Effect of Geometric Imperfections (Wrinkles) on the Circumferential Strength of a Composite Polymer Liner for Pressure Pipes

Authors:	Ampiah, Nancy
Files in This Item: File mirror Size Format Effect of Geometric Imperfections (Wrinkles) on the Circumferential Strength of a Composite Polymer Liner for Pressure Pipes.pdf Link 4.68 MB Adobe PDF
Keywords:	geometric imperfections, wrinkles, composite polymer liner, split-disk test, circumferential strength
Issue Date:	2008
Series/Report no.:	Canadian theses
Abstract:	The relining of deteriorated gravity flow and pressure pipes with polymeric liners is now popular practice. In the water industry, health concerns and challenges associated with re-opening water services in a lined small diameter pipe have limited the use of liners. Sanexen Environmental Services Inc. in Montreal, Canada, manufactures a cured-in-place liner system which can restore water service connections after lining from within the pipe, using a remote controlled robot. The installation of the liner within cast iron water pipes can result in the formation of geometric imperfections (wrinkles) as the external diameter of the liner often exceeds the internal diameter of the host pipe. Previous studies have suggested that the wrinkles have a detrimental effect on the structural performance of the liner. In this study, experimental and analytical investigations were conducted to evaluate further the effect of the wrinkles on the circumferential (hoop) strength of the liner. The experimental investigation involved testing 33-25 mm wide ring samples of the liner with and without wrinkles, using the split-disk test method which is defined by ASTM Standard D2290. The laboratory tests were conducted to examine the effects on the response of the liner of loading rate, cyclic loading, and presence of different wrinkle configurations. A series of two-tailed Mann-Whitney statistical tests were conducted on the obtained test data. The analytical investigation examined the behavior of two of the three types of wrinkles observed in the liner using finite element models. The results from the models were evaluated using the experimental results. This study confirmed that the wrinkles were a source of weakness in the liner as failure was initiated at the wrinkle in all the test samples. It also showed that their presence may or may not result in a reduction in the ultimate hoop tensile capacity of the liner depending on wrinkle pattern. The loading rate had no significant effect on the first cracking load of the resin within the wrinkle. However, lower ultimate hoop tensile capacities were observed at very slow loading rates. Under the 50-year cyclic loading, the resin within the wrinkle was susceptible to cracking while the jackets of the wrinkle remained intact.

ANTHROPOGENIC IMPACTS ON SENSITIVE FRACTURED BEDROCK AQUIFERS

Authors:	LEVISON, JANA
Files in This Item: File mirror Size Format ANTHROPOGENIC IMPACTS ON SENSITIVE FRACTURED BEDROCK AQUIFERS.pdf link 2.86 MB Adobe PDF
Keywords:	groundwater fractured bedrock agriculture PBDEs tracer experiment source water protection
Issue Date:	2009
Series/Report no.:	Canadian theses
Abstract:	Groundwater is an important water resource that must be protected from potential contamination due to anthropogenic activities such as industrial production and agriculture. It is necessary to understand the presence, movement, and persistence of contaminants in aquifers to develop adequate protection plans. Fractured bedrock aquifers with thin overburden cover are very sensitive to contamination, and little is known about transport processes from the ground surface to depth in this setting. Thus, this research was undertaken to improve the understanding of anthropogenic impacts on water quality in a natural fractured bedrock aquifer with minimal overburden protection. This was accomplished through a field-based investigation conducted in an agricultural setting near Perth, Ontario, Canada. The temporal and spatial variations of several contaminants and indicators (including nitrate, E. coli and polybrominated diphenyl ethers) were examined. A unique infiltration tracer experiment was also conducted to simulate the transport of solutes from the ground surface to wells. Results showed that nitrate concentrations were consistent on a daily scale, but varied monthly. In contrast to nitrate, greater bacterial (E. coli) variability was observed daily. E. coli was not identified in some locations for several months. The temporal variability of concentrations is an important consideration for those consuming groundwater in this setting, as concentrations may be acceptable one month while unsuitable another month (or even another day for fecal bacteria). Annual groundwater monitoring will likely not capture maximum concentrations and thus may not protect human health. Polybrominated diphenyl ethers (flame retardants), which had not been previously measured in groundwater, were detected in the study aquifer at concentrations greater than observed in surface water bodies. It is evident that additional surveys of PBDE concentrations in groundwater are warranted. The infiltration tracer experiment showed that solute transport from the ground surface through thin soil to wells in fractured bedrock can be extremely rapid (on the order of hours) although very complex. This is an important consideration for private and municipally owned drinking water systems that draw water from shallow bedrock aquifers. The results of this research demonstrate that protecting water at the source is imperative in order to preserve water quality in sensitive fractured bedrock aquifers with minimal overburden cover.

ASSESSMENT OF THERMAL HEATING FOR THE REMOVAL OF CHLORINATED SOLVENTS FROM FRACTURED BEDROCK

Authors:	RODRIGUEZ, DAVID
Files in This Item: File Description Size Format ASSESSMENT OF THERMAL HEATING FOR THE REMOVAL OF CHLORINATED SOLVENTS FROM FRACTURED BEDROCK.pdf 24.02 MB Adobe PDF
Keywords:	Thermal Heating Chlorinated Solvents Fractured Bedrock
Issue Date:	25-Sep-2012
Series/Report no.:	Canadian theses
Abstract:	The aim of this study was to assess the performance of thermal heating for the removal of chlorinated solvents from fractured rock. The study included a laboratory experimental program, a field pilot study demonstration and a mathematical modeling component. In the laboratory experimental program, thermal heating parameters, such as operational temperature, heating duration, and the corresponding degree of contaminant removal, were evaluated through a series of heating tests. To evaluate the effect of heating temperature and heating duration on the degree of contaminant mass removal, two different heating profiles were utilized during the experiments. Additionally, seven types of rock and two common contaminants were selected to evaluate the effect of thermal heating on different geological media impacted with different chlorinated compounds. In general, results showed that heating duration had the most significant effect on the degree of contaminant mass removal in post-remedy samples. Results showed that a higher porosity in combination with a lower organic content facilitates the removal of chlorinated solvents from the rock matrix. A Thermal Conductive Heating (TCH) pilot test was implemented by TerraTherm, Inc. at the former Naval Air Warfare Center (NAWC) in West Trenton, NJ to assess the performance of TCH for the removal of trichloroethylene (TCE) and daughter products (i.e cis-1,2-dichloroethylene (DCE) and vinyl chloride (VC)) from fractured bedrock. Results showed that treatment removed 318.5 kg of TCE, DCE and VC, from the treatment zone, of which 62.6 kg were recovered from the rock matrix. A total of 63 % TCE, 65.8 % of DCE and 90.4% of VC were removed during heating. Finally, Semi-analytical solutions were derived to evaluate back diffusion in a fractured bedrock environment where the initial condition comprises a spatially uniform, non-zero matrix concentration throughout the domain. It was concluded that the time required to reach a desired fracture pore water concentration is a function of the distance between the point of compliance and the upgradient face of the domain where clean groundwater is inflowing. Hence, shorter distances correspond to reduced times required to reach compliance.

Time dependent response of pulled-in-place HDPE pipes

Authors:	Chehab, Abdul Ghafar
Files in This Item: File Description Size Format Time dependent response of pulled-in-place HDPE pipes.pdf 4.75 MB Adobe PDF
Keywords:	High density polyethylene Horizontal directional drilling Constitutive modeling Pipe-soil interaction
Issue Date:	2008
Series/Report no.:	Canadian theses
Abstract:	Horizontal directional drilling is increasingly used to install pipes without costs and disruptions associated with conventional ‘cut and cover’ installations. This technique, which was developed by industrial innovators, feature complex soil and pipe response which is not well understood. The success of this operation depends on knowledge of the pulling forces applied, level of ground disturbance, ground expansion or fracture from mud pressure, and the effect of the pulling operation on the pipes. Tensile stresses in the pipe vary with time during and after installation, and along the pipe. This applies especially to polymer pipes where the stresses during insertion and those over the service life of the pipe may influence its performance. The main objective of this study is to model the short term and long term response of pipes installed using horizontal directional drilling and to investigate the effect of the time dependent behaviour of polymer pipes, as well as other installation variables on the performance of the pipe during and after installation. The mechanical behaviour of high density polyethylene used to manufacture a significant portion of pipes installed using horizontal directional drilling is investigated and two sophisticated constitutive models are developed to simulate the time-dependent behaviour of high density polyethylene. The interaction between the pipe and the surrounding soil during horizontal directional drilling installations is also investigated and modelled. A FORTRAN algorithm is developed to calculate the short and long term response of elastic and polymeric pipes installed using horizontal directional drilling. The program uses the HDPE constitutive models as well as the pipe-soil interaction model developed in the study. After evaluation, the developed program is employed in a parametric study on the sensitivity of short term and long term pipe response to different parameters, including the effect of overstressing the pipe during installation. As Multiaxial modeling is necessary for accurate analysis of some applications including the swagelining method, a uniaxial constitutive model developed in the current study is generalized to a multi-axial model that can simulate the response to biaxial stress-strain fields. The multi-axial model is implemented in a finite element code and its performance in simulating multiaxial stress-strain fields is evaluated.

INVESTIGATION INTO THE ATTENUATION OF METALS IN GCLS INTENDED FOR MINE WASTE CONTAINMENT

Authors:	Lange, KARINA
Files in This Item: File Description Size Format INVESTIGATION INTO THE ATTENUATION OF METALS IN GCLS INTENDED FOR MINE WASTE CONTAINMENT.pdf 18.97 MB Adobe PDF
Keywords:	geosynthetic clay liners barrier mining metals
Issue Date:	2009
Series/Report no.:	Canadian theses
Abstract:	This research evaluated the use of geosynthetic clay liners (GCLs) as a potential barrier material to the migration of metals that are leached from mine waste. This thesis consists of two parts. In the first part, micro analytical methods including µXRD with synchrotron-generated µXRF elemental mapping and synchrotron-based µXRD (S-µXRD) were used to characterize the GCL bentonite and distinguish how mechanisms of metal attenuation could be identified. These analytical methods were of particular use for the clay material as they offer non-destructive, in situ investigation of various soil characteristics with microspatial resolution. The combination of the analytical methods allowed for identification of minerals such as gypsum and pyrite, not accessible by conventional methods. In particular, distinguishing accessory crystalline phases present in the “starting material” bentonite from those formed as a result of interaction with metal-bearing leachates is critical, as the development of metal-attenuating crystalline phases can have a significant long-term impact on metal mobility. In the second part of the thesis, the migration behaviour of metals (As, Al, Cd, Cu, Fe, Mn, Ni, Sr, and Zn) was investigated by means of diffusion tests and permeation experiments using four metal-containing waters: acidic rock drainage (ARD), lime-treated ARD, water from gold mine tailings, and landfill leachate with metal loading. Effective diffusion coefficients of the metals were calculated by modelling laboratory diffusion and sorption data. Water pre-hydrated GCLs were permeated with 15-21 pore volumes (PVs) of solution and their interaction with these solutions was examined in terms of both the hydraulic conductivity and the change in the geochemical characteristics of the permeant over time. The greatest increase in hydraulic conductivity occurred for the acidic rock drainage, where it increased from 1.6x10-11 m/s to 1.3x10-10 m/s following 21 PVs of permeation; still a very low value when compared to regulatory standards for clay barrier materials. Observed delayed breakthrough curves were indicative of the GCL’s strong attenuation capacity for a number of metals. An understanding of mechanisms of metal retention at both the micro and macro-scale levels will facilitate effective pollution prevention using GCLs.

Ground movements during tunnelling in sand

Authors:	Thorpe, Jason Peter
Files in This Item: File Description Size Format Ground movements during tunnelling in sand.pdf mirror 2.73 MB Adobe PDF
Keywords:	Tunnelling Centrifuge Ground movements
Issue Date:	2008
Series/Report no.:	Canadian theses
Abstract:	During soft ground tunnel construction, if the face pressure of a tunnel boring machine is not strictly controlled, excessive ground movements will propagate vertically upwards causing significant damage to adjacent buried infrastructure and surface structures. In order to investigate the face pressure - ground deformation relationship for tunnels in sands, the construction process was modelled using the technique of geotechnical centrifuge modelling and the resulting ground deformations were recorded using digital image correlation. In these tests a unique tunnel face boundary condition was developed which allowed the boundary condition to be initially set as a zero strain condition before it was transformed into a load-controlled boundary to investigate the instability of the face. Tests were preformed at four different burial depths in dry sand, corresponding to cover depths of 0.5, 1, 1.5, and 2 times the tunnel diameter. These results indicate that the face pressure at failure is largely independent of burial depth over the values tested. The ground deformation at the onset of tunnel face instability was found to be very small, and once initiated, the zone of ground deformations was observed to propagate upwards in a narrow chimney in front of the tunnel until it reached the ground surface causing subsidence. Further tests investigated the variation in ground deformations to be expected if a tunnel were to be passing through more complex ground conditions, including unsaturated sand, saturated sand, and the unique case of sand / clay mixed ground conditions. Ground deformations at tunnel face instability were much lower for the case of unsaturated sand, than for either the saturated or dry cases which showed broadly similar responses. In the mixed ground condition of a clay layer over topping a sand layer, the clay layer was found to only influence the tunnel face pressure – deformation response if the bottom of the clay layer was closer than 0.5 diameters above the tunnel crown.

Laboratory study evaluating thermal remediation of tetrachloroethylene impacted soil

Authors:	Burghardt, Julie Marie
Files in This Item: File Description Size Format Burghardt_Julie_M_200712_MSc(Eng).pdf 2.61 MB Adobe PDF
Keywords:	Thermal DNAPL Remediation PCE
Issue Date:	2008
Series/Report no.:	Canadian theses
Abstract:	A laboratory study was conducted to assess the relationship between degree of volatile organic compound (VOC) mass removal from soil and heating duration, initial dense non-aqueous phase liquid (DNAPL) saturation, and grain size. The relationship between post-remedy sampling temperature and VOC soil concentration was examined. Soil contained in glass jars was spiked with DNAPL phase tetrachloroethylene (PCE), saturated, and placed in an oven for a specified period of time. The soil temperature at the centre of each jar was monitored during heating. Upon removal from the oven, each jar was immediately capped with an air tight seal and placed into an ice bath until the soil temperature had cooled to the desired sampling temperature. The jar caps were subsequently removed and the soil was sampled using a coring tool and immersed into pre-weighed vials containing methanol. PCE in soil samples was quantified using purge-and-trap with gas chromatography/mass spectrometry. Soil temperature increased steadily from ambient until reaching a plateau at 89 ºC ± 4 ºC due to co-boiling of DNAPL phase PCE and water. A linear relationship was found between the length of the co-boiling plateau and the initial PCE saturation. Co-boiling continued until DNAPL phase PCE had been depleted, at which time the soil temperature increased to the boiling point of water and remained constant while remaining pore water was removed. PCE soil concentrations decreased rapidly in the early stages of heating, but leveled off between 9.0 and 19 ppb soon after the soil became dried out. Analysis of the sensitivity to initial PCE saturation data revealed that the concentration of PCE in post-remedy samples increased with increasing initial saturation. Results of the sensitivity to grain size tests showed a decreasing trend between PCE soil concentration and decreasing sand grain size while temperature at sampling was not found to affect the amount of PCE quantified post-thermal remedy. Soil temperature at the centre of each jar during cooling was measured and an analytical solution was fit to the recorded data. From this data, the thermal diffusivity of the soil was approximated and was found to range from 1.4 x 10-7 to 1.8 x 10-7 m2/s.

3-D Analysis of Building Frame Using STAAD-PRO

Behera, Ashis Debashis (2012) 3-D Analysis of Building Frame Using STAAD-PRO. BTech thesis.

PDF 2921Kb

Abstract

In these modern days the Buildings are made to fulfill our basic aspects and better Serviceability. It is not an issue to construct a Building any how its, important to construct an efficient building which will serve for many years without showing any failure. The Project titled “3-D ANALYSIS OF BUILDING FRAME USING STAAD-PRO”, aims in finding Better technique for creating Geometry, Defining the cross sections for column and beam etc, Creating specification and supports (to define a support weather it is fixed or pinned),then the Loads are defined. After that the model is analyzed by ‘run analysis’. Then reviewing (whether beam column passed in loads or failed) results. Then the design is performed.

Item Type:	Thesis (BTech)

Performance based earthquake design

Bansal, Ankush (2012) Performance based earthquake design. BTech thesis.

PDF 2563Kb

Abstract

Every Civil Engineering structure or building is unique in nature unlike other engineering products which are produced in a massive scale using the same technique again and again. The present Project is an effort to understand Performance Based Design Approach. In this Work an four storey office building is designed using STAAD.Pro and a nonlinear static analysis is carried out using point plastic hinge model. After the building is designed it is imported to SAP platform in order to model point plastic hinges and carry out Pushover Analysis. The designed building was modeled and the hinges or possible failure locations were assigned. The stiffness of the building was increased due to the slab present and this was incorporated in the model using diaphragm. The Floor Centre of Mass was calculated and an incremental Inverted triangular loading was applied to this central load and the base shear along with displacement of this building was recorded until the building reached a state of collapse. The Displacement controlled Pushover Analysis was carried out and the Pushover Curve were obtained for the building in both the direction i.e. X and Y. The Pushover curve is analyzed for various percentage of displacement. As per FEMA 356 typical values of roof drifts for the three performance levels are as follows.
i) Immediate Occupancy: Transient drift is about 1% with negligible permanent drift.
ii) Life Safety: Transient drift is about 2% with 1% permanent drift.
iii) Collapse Prevention: 4% inelastic drift, transient or permanent.
The Capacity Spectrum, Demand Spectrum and Performance point of the building was found in both the direction using the analysis carried out in SAP 2000 (v14). From the Performance point it was found that the Base Shear carried by the building is well above the design base shear and the building can take a lateral force up to 10% of the seismic weight of the building. The Displacement obtain was less than 1% and hence the chances of crossing the elastic state for the building was very less. Very Rare chances are there for the building to cross Life safety performance level. In the collapse state the failure was due to the collapse of ground floor Columns which is a serious issue and should be looked for further research. The Building designed as per Indian standards was found to be well above Life safety performance level considering Designed Based Earthquake .

Critical evaluation of torsional provision in IS-1893: 2002

Balakrishan, Bijily B (2012) Critical evaluation of torsional provision in IS-1893: 2002. MTech thesis.

PDF 1562Kb

Abstract

For a building to be symmetric it must have, at each floor level, coincident centers of mass and stiffness that lie on common vertical axis. In practice, this condition is rarely encountered and most buildings are unsymmetrical to varying degrees, due to asymmetry in plan, elevation, distribution of vertical members or mass distribution on the floors. Although considerable research on response of asymmetric structures under seismic excitation has been reported in the literature, the performance of asymmetric structures designed in accordance with the Indian code has not been studied adequately. Frequent occurrences of devastating earthquakes in India clearly call for the need of evaluation of Indian buildings for seismic safety.
The earthquake resistant code in India, IS: 1893 (Part1), has been revised in 2002 to include provisions for asymmetric buildings. An attempt has been made in the present study to investigate the gap in the seismic design of asymmetric RC structures in the Indian context. Three reinforced concrete moment-resisting frame buildings with different types of asymmetry are designed based on prevailing Indian codes as test examples. Nonlinear static (pushover) and dynamic (time-history) analyses are performed on these structures and a comparison is made of displacements, inter-storey drift ratio, ductility and hinge pattern of the frames to show the changes in their behaviour due to torsion which is recognized as a principal cause of severe damage in eccentric multi-storey buildings during earthquakes. Nonlinear dynamic analysis (time history analysis) is done for ten recorded ground motion and five generated ground motion consistent to IS-1893: 2002 (Part1) response spectrum.
Results obtained from this study show that the plan asymmetry in the building makes it non-ductile even after design with code provision. The maximum base shear demands for the three building variant are almost same. This is because the fundamental periods of all the three building are almost identical. It is found that there is a considerable amount of variation in the maximum roof displacement responses of the three building variants subjected to generated earthquake ground motion. The maximum roof displacement responses for symmetric building variants are found to be lesser compared to the two asymmetric buildings for all the cases studied here. However the average maximum roof displacement responses for two asymmetric buildings are found to be approximately same.
Base moment demand obtained from nonlinear dynamic analyses is found to be almost same for both of the two asymmetric buildings for all the cases studied here. Also, in most of the cases base shear – roof displacement and base moment – roof rotation hysteresis curves are found to be similar for both the asymmetric buildings with small translational/rotation shift.
It is found that the yielding for both the asymmetric building occurs at the same time step of the dynamic analyses after following the same elastic eccentricity even though ASYM2 (designed with code provision) has a greater strength compared to ASYM1 (designed without code provision).
Considering that all the building structures will undergo inelastic deformation under an expected earthquake it is meaningless to relate the design criterion to the elastic centre of rigidity. Design criterion given in IS 1893:2002 (Part-1) with regard to plan asymmetry seems to be not very efficient. Code criterion for plan asymmetry recommends increasing the strength distribution in the building but it does not look for changing the stiffness distribution of the building. Change in the stiffness distribution to reduce eccentricity can be a useful for such buildings.

Velocity Distribution at the Cross-Over of Sinusoidal Trapezoidal Meandering Channels

Bage, Prasanta and Sudhir, Jena (2012) Velocity Distribution at the Cross-Over of Sinusoidal Trapezoidal Meandering Channels. BTech thesis.

PDF (thesis) 1895Kb

Abstract

Evaluation of velocity distribution process longitudinally is very much essential for the environmental management, quantifying the mean velocity. In nature, most rivers tend to be of compound sections as well as meandering [1]. Velocity distribution is crucial for solving many engineering problems such as management of rivers and floodplains, it is important to understand the behaviours of flows within compound channels for designing of hydraulic structure, flood control, water management, sedimentation and excavation. During flood runoff water comes out natural or man-made channel, part of the discharge is carried out by simple main channel rest are carried out by flood plain. Experiment results are presented here for the studies conducted in two self designed channels, developed by known discharge. These data’s were used for the analysis of velocity distribution and depth average. Velocity at the cross-over of a meandering channel of different sinuosity at various flow depth where investigated for monitoring the contour mapping of flow and graphical analysis of velocity at the cross-over.

Response of extended eulerbernoulli beam under impulse load using wavelet spectral finite element method

B, Mallikarjun (2012) Response of extended eulerbernoulli beam under impulse load using wavelet spectral finite element method. MTech thesis.

PDF 1447Kb

Abstract

Transform methods are some of those methods which are able to solve certain difficult ordinary and partial differential equation. The most commonly used transform for these solutions are Laplace and Fourier transforms. Wavelet transforms are new entrants in to this area, although
they are quite popular with electrical and communication engineers in characterizing and synthesizing the time signals. The utility of wavelet transforms is shown in structural engineering by addressing problems involving solutions of ordinary and partial differential equations
encountered in dynamical related problems.
Dynamical problems in structural engineering fall under two categories, one involving low frequencies, which is called structural dynamics problems, and the other involving very high frequencies, which is called the wave propagation problems. The most problems in structural engineering fall under the former category, wherein the response of the entire structural system is characterized using only the first few vibrational modes. The wave propagation is a multi-modal phenomenon involving vibrational modes of very high frequencies. Conventional analysis tools
such as finite element cannot handle these problems due to modeling limitations and extensive computational cost. The only alternative to such problems is the method based on transforms.Spectral finite element (SFE) method is one such transform method, which can be a viable alternative to solving problems involving high frequency excitations. SFE based on Fourier transform is quite well known and established. However, it has severe limitations in handling
finite structures and specifying non-zero boundary/initial conditions, and thus its utility in solving real world problems involving high frequency excitation is limited.
The aim of the present work is to show that the wavelet transform is very useful in solving ordinary differential equations by modeling the structure as a discrete system involving structural dynamic problems and it is to use wavelet transform to solve those problems involving partial
differential equations. In this work, the response of an cantilever Extended Euler-Bernoulli aluminum beam under impulse load applied axial and transverse at the free end is shown. The response is being obtained by coding programs in MATLAB.

Seismic Evaluation of Institute Building,NIT Rourkela

Agrawal, Ankur (2012) Seismic Evaluation of Institute Building,NIT Rourkela. BTech thesis.

PDF 2654Kb

Abstract

There are many buildings which do not meet the current seismic requirement and suffer extensive damage during the earthquake. In 1960 when the institute building of NIT Rourkela was constructed, the seismic loading was not considered. The building is only deigned to take the dead and live loads. Evaluating the building for seismic conditions gives an idea whether the building is able to resist the earthquake load or not. The objective is to evaluate an existing building for earthquake performance. Firstly preliminary evaluation is done and then detailed evaluation is carried out. For applying earthquake loads, equivalent static lateral force method is used according to IS 1893(Part 1):2002. The Demand Capacity Ratio (DCR) is carried out for beams and columns in order to evaluate the member for seismic loads. Since the reinforcement details of the building were not available as it is more than 50 years old, Design-1 is prepared applying only DEAD and LIVE loads according to IS 456:2000. This helps in estimating the reinforcement present in the building and in assuming that this much reinforcement is present. In Design-2 seismic loads are applied and from this demand obtained from design-2 and capacity from design -1, the DCR is calculated. If demand is more than capacity, the member fails and vice versa. STAAD-Pro V8i is used for loading and designing the building.

Application of fuzzy logic to model trip generation phase of sequential travel demand analysis

Agarwal, Abhishek (2012) Application of fuzzy logic to model trip generation phase of sequential travel demand analysis. BTech thesis.

PDF 1831Kb

Abstract

Sequential travel demand analysis consists of four phases, namely, trip generation, trip distribution, modal split and route assignment. Although, the later three phases are supported with quite sufficient number of efficient models; the first one, i.e., trip generation being completely based on human decision making is not supported with any efficient model. Existing models on trip generation are deterministic in nature and cannot capture the inherent vagueness of human mind regarding trip choice. Generally, the models of trip-generation include variables which reflect the number of potential trip-makers and the propensity of potential trip-makers to make a trip. However, none of the present models incorporate variables which reflect the accessibility factor. This is possibly the single largest factor as to why trip-generation models cannot very well predict the number of trips generated. It is intended to apply fuzzy logic, which is a linguistic tool to capture the imprecise nature of human mind regarding trip decision. Also, existing models on trip generation do not cover important premise variables controlling trip generation. In the proposed model it is intended to embed it properly.
To validate the developed model empirical data is used.