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ThesisItem Open Access Study on Load Carrying Capacity of Unreinforced Slopes with Varied Footing Shapes and Edge Distance using PLAXIS 3D(Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, 2023-02-01) Arya, Manish; Suman, SanjeevIn Uttarakhand's hilly regions, construction of shallow footings close to sloping ground is very common. Special care must be taken when estimating the load carrying capacity of such footings beacuase the slope geometry interferes with the footing's failure zone. The choice of footing on unsupported sloping grounds becomes important because different footing shapes have different load distribution patterns which gives different load carrying capacities. The improper formation of the passive resistance zone toward the face of the slope may significantly reduce the bearing capacity of the foundation for footing placed on the crest or on the face of a slope. For the presented research problem, the slopes were modeled in the PLAXIS 3D software with slope angles of 15°, 20°, 25°, 30° and 35°and with different shaped footings (square, rectangular, circular and trapezoidal), placed at different edge distances of 1m, 2m, 4m, 6m and 8m having same bearing area of 4m2 for each type of footing. A total of 100 models were prepared in the PLAXIS 3D for the analysis of load carrying capacity of footing resting near unreinforced slope for various cases. The soil is of loamy type and its properties are taken from a landslide prone area named Kakri Ghat in Nainital district of Uttarakhand. The effect of slope angle and distance of footing from the edge of the slope on the load carrying capacity of the footing have been researched and findings are discussed in detail. The results are later verified with the analytical methods and the edge distances after which the effect of slope angle gets nullified is verified with the charts given by Kusakabe (1981). It has been concluded that the load carrying capacity of the footings increases with the increase in the edge distance and decreases with the increase in slope angle. The effect of shape of the footing on LCC is complex phenomenon and the results are different for different case scenarios. The best footing shapes for various cases for maximum load carrying capacity are discussed in the chapter 4.ThesisItem Open Access Assessment of water potential underground in Suyal watershed Almora, using analytic hierarchical process and GIS approach(G. B. Pant University of Agriculture and Technology, Pantnagar, 2022-04) Joshi, Ritesh; Shiva Prasad, H.J.With the increase in water consumption and climatic variation hundreds of spring fed water shed is at a great threat. Due to decline of discharge in conventional water resources crop land has also shrinked which has affected the economy of region to a great extent. Underground water is present in form of porous aquifer and springs in hilly and mountainous regions. Due to lack of maintenance and over exploitation many conventional water sources are at verge of extinction. In this study GIS- based weighted sum analysis approach was used to identify sites of water potential zones which can be used for both water extraction and rejuvenation of these conventional water sources in Suyal river watershed. GIS based tools can be used for studying of relief and structural aspects of basin. Different factors were quantified and the influence of each factor over is judged. Results show that 21% of area lies under good recharge potent ability while 79% area lies under poor ground water potential region. Areas with good to excellent recharge potential may be considered for augmentation measures to sustain its specific yield in the future.ThesisItem Open Access A study of settlement behaviour of piled raft foundation using PLAXIS 3D(G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2022-10) Behl, Shubham; Subir KumarA Pile Raft foundation is a type of geotechnical foundation that consists of three components: the raft, the piles and the soil domain. Piled raft foundations (PRF) are commonly used under high-rise buildings and other heavy structures because of their effective load transfer mechanism, which allows the superstructure loads to be partially carried by the raft and partially by the piles. In the present study, an effort to figure out settlement response of a piled raft foundation on a multi layered soil by varying raft thickness, length of piles and diameter of piles by using PLAXIS 3D is made. Settlement at different loading rate have also been observed using the software and a load v/s settlement response has been plotted. PLAXIS 3D which is based on finite element method was used to analyse this complex problem of soil structure interaction and settlement was calculated. It was found that raft thickness has no significant effect on the load settlement relationship of a piled raft foundations either on small settlements or on large settlement levels. A significant decrease in settlement was also observed with increase in length and diameter of pile.ThesisItem Open Access Prediction of the scour depth around bridge piers using HEC-RAS model and empirical equations(G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2022-09) Dinesh Kumar; Mahar, P.S.The main cause of the collapse of a hydraulic structure such as a bridge is the scouring around the bridge piers. The discharge, depth of flow, morphology of the pier, and distribution of sediment particle size all have a role in the complicated process known as scouring. The scour depth at the piers of the Gaula bypass road bridge in Haldwani, India, has been evaluated in the current study using empirical equations and the HEC-RAS numerical model and the results are compared. A flood frequency study using Gumbel's distribution method has been conducted for the Gaula river Haldwani basin in Uttarakhand, India. In the study, floods having a return period of 5 to 1000 years have been considered. Grain size distribution analysis was performed for the soil samples collected from the river bed near the bridge piers to calculate d50 and d95. Using field data, a hydraulic model of the river at the bridge location was developed. Then, variations in flow discharge for scouring along the bridge were explored by inputting the scouring data of bridge piers for discharges with return periods of 5 to 1000 years. The study has revealed that several of the empirical equations are not sensitive to an increase in flow discharge, and the results are similar for floods of different return periods. However, the centre and lateral piers of the bridge showed an increase in scouring as the flow increased, according to the results of the HEC-RAS model. The scour depth pattern is nearly constant throughout all discharges. Additionally, the increasing discharge has a significant impact on both the left and right abutments. The scour depths for discharges with return periods of 5 and 1000 years were 5.47 m and 10.22 m, respectively by HEC-RAS. The effect of a gabion check dam proposed downstream of the bridge on the siltation of scoured river beds near the bridge piers and abutments has been also investigated by using HEC-RAS. In the study, it has been found that the river bed profile elevation gets significantly increased as a result of the construction of the check dam.ThesisItem Open Access Comparative study of irregular RC building with shear wall and steel bracing under seismic loading(G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2022-09) Ankit Kumar; Ankit Kumar; Vaneeta Devi; Vaneeta DeviThe requirement of a multi-storey buildings is increasing day by day, but these buildings are highly affected by lateral loads. These lateral loads can be resisted by improving the lateral load resisting capacity of the building by the use of shear wall and steel bracing in the building at suitable locations. In the present study, the analysis of G+10 irregular RC building with shear wall and steel bracing at different locations in the building has been performed. The seismic forces are considered as per IS: 1893 (Part1) - 2016 and dead load, live load and other finishing loads are considered as per IS: 875 Part 1 and 2 in the analysis of various models considered in the present study. The building is considered in seismic zone V with damping ratio of 5%. Seismic analysis has been done using Response Spectrum method of dynamic analysis. 3D models of building with shear wall and steel bracing at different locations have been modelled and analyzed using “ETABS” software. The response parameters namely base shear, storey drift and torsion are critically analyzed to quantify the effects of shear wall and steel bracing at different locations in building. It has observed that base shear and torsion increases with the use of shear wall and steel bracing in irregular building as the stiffness of the building increases. The storey drift in the building decreases due to the increased stiffness. Since torsion is the most critical factor leading to major damage or complete collapse of buildings therefore, it is very essential that irregular buildings should be carefully analysed and designed for torsion. The performance of considered irregular building for stipulated sizes with shear wall is found better than steel bracing systems. Shear walls are definitely good mechanism for lateral loads itigation but the position of shear walls in the building should be made judiciously. In the present study, the Shear walls at exterior corners (Model 5) has found perform better than other modal cases being considered in the analysis.ThesisItem Open Access Analysis of bearing capacity of layered soil(G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2022-10) Sweta; Gupta, S.S.Load bearing capacity of the foundation is the major concern in the field of geotechnical engineering. Ultimate bearing capacity can be defined as the least pressure at which soil undergoes shear failure. The ultimate bearing capacity of a foundation on layered soil is very important as it is a prerequisite to any design. The parameters upon which safe bearing capacity of soil depends are shape of the foundation, soil layering, depth of foundation, etc. The parameters selected for the present study were thickness of top layer of soil and width of the footing. For the present study, soil sample has been extracted from the site at Fazalpur in Rudrapur. Initially a numerical model was undertaken using finite element method (FEM), PLAXIS 3D. Three dimensional models in this study were represented using finite element analysis which in turn is based on Mohr coulomb failure criteria. The method used to analyse two layered soil systems was Meyerhof and Hanna method. The outcomes from PLAXIS 3D software and the classical approach (Meyerhof and Hanna) were compared. During the study it was observed that the bearing capacity of soil is directly proportional to the thickness of the top layer of the soil and inversely proportional to the length to width ratio of footing. The percentage variation between the results were from 2.32% to 14.89%. The variation was expected due to the detailed analysis of the soil layers in PLAXIS 3D while the manual method was based on Meyerhof and Hanna method.ThesisItem Open Access Reliability based optimal design of domestic sewer networks(G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2022-09) Rawat, Manisha; Mahar, P.S.A sewerage system is made up of a network of sewage pumping stations, manholes, and sewer pipes. Different types of sewers like house sewers, lateral sewers, branch sewers and trunk sewers carry sewage from individual residences to the sewage treatment plant. Along the sewer system, manholes are provided for maintenance, cleaning, and repair work. The main objective of this study is to build a linear optimization model for design of gravity-fed sewerage systems to dispose domestic wastewater utilizing the Darcy-Weisbach equation. The developed optimization model minimizes the total cost of the gravity-fed sewer line that meets the minimum and maximum velocity requirements to serve the desired population. Further, the viscosity of the sewage is taken in to account in the developed model. The output from the model is the pipe sizes and slopes of the lateral sewers and trunk sewer. The developed linear optimization model is applied to the Zone L phase I sewer network of Dehradun city. The total number of variables and links are 5868 and 652, respectively. Reliability of the optimally designed gravity-fed sewer network is calculated for trunk line by using first order analysis of uncertainties. Relation between risk and coefficient of variation for mean loading rate is also studied.ThesisItem Open Access Prediction of the scour depth around bridge piers using HEC-RAS model and empirical equations(G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2022-09) Dinesh Kumar; Mahar, P.S.The main cause of the collapse of a hydraulic structure such as a bridge is the scouring around the bridge piers. The discharge, depth of flow, morphology of the pier, and distribution of sediment particle size all have a role in the complicated process known as scouring. The scour depth at the piers of the Gaula bypass road bridge in Haldwani, India, has been evaluated in the current study using empirical equations and the HEC-RAS numerical model and the results are compared. A flood frequency study using Gumbel's distribution method has been conducted for the Gaula river Haldwani basin in Uttarakhand, India. In the study, floods having a return period of 5 to 1000 years have been considered. Grain size distribution analysis was performed for the soil samples collected from the river bed near the bridge piers to calculate d50 and d95. Using field data, a hydraulic model of the river at the bridge location was developed. Then, variations in flow discharge for scouring along the bridge were explored by inputting the scouring data of bridge piers for discharges with return periods of 5 to 1000 years. The study has revealed that several of the empirical equations are not sensitive to an increase in flow discharge, and the results are similar for floods of different return periods. However, the centre and lateral piers of the bridge showed an increase in scouring as the flow increased, according to the results of the HEC-RAS model. The scour depth pattern is nearly constant throughout all discharges. Additionally, the increasing discharge has a significant impact on both the left and right abutments. The scour depths for discharges with return periods of 5 and 1000 years were 5.47 m and 10.22 m, respectively by HEC-RAS. The effect of a gabion check dam proposed downstream of the bridge on the siltation of scoured river beds near the bridge piers and abutments has been also investigated by using HEC-RAS. In the study, it has been found that the river bed profile elevation gets significantly increased as a result of the construction of the check dam.ThesisItem Open Access Study of seismic performance of RC building with different infill wall materials using pushover analysis(G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2022-10) Bisht, Dhirender Singh; Sunil KumarAmong all-natural disasters, earthquakes are the most unexpected and destructive ones, and it is extremely challenging for an engineer to figure out the design for a structure that behaves well under upcoming seismic events and stays within the constraints of economy and life safety. The study of the seismic performance under earthquakes is not simple due to random and fast seismic vibrations in the base of the structure. In the present study, the pushover analysis of a G+3 RC building is done and the effect of infill wall has been considered using two approaches viz. Typical Consulting Practice (TCP) and Infilled Modelling Approach (IFM). The TCP is a generalized and common approach in which the only load of infill wall is taken in the model. Whereas infill walls are modeled as struts in IFM approach as per the procedure given in IS 1893: 2016. The latter is normally not practiced in structural design offices. The building is analyzed using structural analysis software ETABS 20. Two types of infill wall material viz. brick infill and Autoclaved Aerated Concrete (AAC) blocks are considered. Design forces like maximum axial forces in columns, maximum sagging bending moment in beams storey displacement, mode shapes and capacity curve are compared for TCP and IFM approach. It is observed that modelling of infill panels, indeed, largely affect the seismic assessment. The design forces decrease significantly by using AAC blocks. This justifies the reason for AAC blocks being an emerging choice among many builders.
