Civil Engineering

Analysis of earth dams Stability, and their arching phenomenon, is one of the most important issues in geotechnical engineering. Arching dam, you can use one or more methods are analyzed. The main factor of instability dams, gravity effect, but other factors can, intensify or provoke them to be effective. To understand the factors intensifying landslide, could contribute significantly to the experts, and the stability of the dam dirt, and prevent the arching. The purpose of this paper is to examine the phenomenon of arching in the bathroom tight barrier with finite element method, and compared with studies of dam instrumentation, numerical analysis by finite element software PLAXIS, has been made. Analysis, using behavioral models Mohr-Coulomb, is done. On the other hand, we can say that, numerical methods in the analytical methods is very rapid, reliable and accurate, and therefore these methods, able to perform parametric studies, the boundary conditions are complex. So in this study, AH stresses dam Tang-e Hamam, has been studied, and then perform parametric studies, it was concluded that increasing the angle of internal friction shell dam, the dam will lead to increased confidence. However, by changing the geometry of the dam core, core thickness miles to miles and increase confidence rises Dam. Also, the arching, the barrier height is variable, and strongly arching and the maximum arching, core thickness depends on the height of the dam.

The environment of Dhaka city is depraving gradually day by day because of unplanned urbanization, destruction of greeneries by increasing building and economical activities areas to meet the demand of migrated people. This scenario is enhancing the negative change in climate gradually. It is one of the main causes of Buriganga river pollution because of climate change impact. Dhaka city, a capital of Bangladesh, which largely depends on the Buriganga River’s water for drinking, fishing, carrying merchandise and transportation.. The quality of water in this river was very poor and the average DO, BOD5, COD, Nitrate and Phosphate concentration in mg/L were 1.11, 82.3, 148.45, 5.92 and 5.83 respectively. This study mainly focused the climate change impact in term of rainfall on Buriganga River and disclosed it that decreasing the rate of rainfall affect the discharge of river because of climate change and increasing the rate of waste water because of incremental economical activities in industries both affects the dilution rate of Buriganga River simultaneously and this scenario will be also big concern in future for increasing climate change impact on rainfall in Dhaka City. In this study, we also discussed about pollution status of this river and finally the way to mitigate or minimize the pollution of Buriganga River.

For the efficient design of structure it is necessary to do the exact analysis of the elements. There are several methods of analysis broadly classified into classical and approximate method classical methods give exact solution but has its own constraints like magnitude of structure & specific geometrical dimensions. To overcome this and for rapid processing approximate methods are adopted. One such method is finite element method. Even though the results are said to be approximate but with keen consideration the variance is as good as negligible.The aim of this dissertation work is to find out the factors like shape & size of elements for gaining more accurate analytical result. The work over here is done by considering a plate with various shape & size & comparative results are depicted in the observation tables. It is clear that accuracy in the result can be obtained with refined meshing and considering Triangular shape element.

Not all soils are susceptible to liquefaction, there are many works that have aimed to classify the soils based on their susceptibility to liquefaction, and among them the notable ones are : Youd’s criteria of liquefaction, Boulanger and Idriss’ criteria for liquefaction and there are Chinese criteria that are widely used. Because liquefaction has frequently been observed to occur at the same location when site conditions are unchanged (Youd, 1984), evidence of the historical occurrence of liquefaction, either observed or in the form of paleoliquefaction, can be taken as evidence of liquefaction susceptibility. Geologic conditions can also indicate susceptibility to liquefaction; soils deposited in fluvial deposits, and colluvial and aeolian deposits when saturated, are likely to be susceptible to liquefaction. Liquefaction is also observed in alluvial-fan, alluvial-plain, beach, terrace, playa and estuarine deposits, but not as consistently as in those listed previously. Younger soil deposits are generally more susceptible to liquefaction than older deposits. The physical composition of a soil deposit will play a strong role in determining its liquefaction susceptibility (Kramer, 1996). Uniformly graded clean sands composed of rounded particles are inherently most susceptible to liquefaction. Well-graded soils and soils with angular particles are less susceptible. The presence of fines, particularly plastic fines (PI>10) tends to decrease liquefaction susceptibility. The liquefaction potential of a soil deposit can be studied via the mechanical properties of the deposit too. It is done by defining two parameters which govern the behaviour of the deposit during dynamic earthquake loading. The first being the CRR called the cyclic resistance ratio and CSR called the cyclic stress ratio, the CRR tells the total stress ratio required to cause the liquefaction, and the CSR is the stress ratio that is acting on the soil during earthquake loading. Quite obvious is the fact that if the ratio CRR/CSR is less than unity it will mean that the soil can take less stress than what is acting on it and will liquefy. The present study aims at studying the susceptibility of the site to liquefaction and then arrive at the most important site parameter that determines the susceptibility of a soil deposit to liquefaction. The site under study is located in a severe earthquake prone region of the world, "THE KASHMIR VALLEY, INDIA J&K".

This paper presents the effect of Treated Domestic Waste water (TDW) and lime dosage on cube compressive strength of cement mortar prepared with ordinary port land cement and Portland pozzolana cement. The treated domestic waste water was used as replacement to portable water in the proportion of 0,25,50,75 and 100%. From all the replacements, 50% TDW is noticed as effective based on cube compressive strength. This replacement was kept constant and the lime is added to the effective replacement of portable water in the proportion of 0 to 30 with an increment of 5% by weight of water. From the results is found that, for OPC and PPC mortars the optimum dosages were noticed as 20 and 25% respectively. To compute compressive strength results for lime based mixes a regression model was developed and it was verified with experimental results.

The study has attempted to observe three models of biogas system using twenty liter plastic containers as digesters with Cow Dung (CD) and Poultry Droppings (PYD) organic wastes. The cow dung and poultry dropping were mixed separately with water in a ratio of 1:1 (v/v) and the slurry was properly stirred. Thereafter Treatments A, B, C, D and E were prepared using previously made slurry with the following specific proportions as (100% CD + 0% PYD), (75% CD + 25% PYD), (50% CD + 50% PYD), (25% CD + 75% PYD) and (0% CD + 100% CD). Three replicates were carried out for each sample. The plant consists of the fermentation chamber, the inlet and outlet pipe, the gas pipe and the stirrer. The samples were tested for methane and carbon dioxide productions along with pH and Temperature for 31days. Treatment D which is a mixture of (25% cow dung and 75% poultry droppings) produced more methane than the rest of the treatments. 96.08%. The cumulative methane yields of treatments D, A, C, E and B were 96.08%, 83.16%, 72.3%, 46.9% and 36.04% respectively. The order of both methane and carbon dioxide productions production was 25% CD + 75% PYD > 100% CD + 0% PYD > 50% CD + 50% PYD > 0% CD + 100% PYD > 75% CD + 25% PYD.The study revealed further that the mixture of Cow Dung and Poultry Droppings as waste was great potentials for generation of biogas and its use should be encourage due to its early retention time and high volume of biogas yields than other organic waste. Also in this study, it was found that temperature variation, pH and some of the factors that affected the volume yield of biogas production.The main objectives of this study were to evaluate the variation of methane and carbon-dioxide production from Cow Dung and Poultry Droppings both individually and combined as substrates and also to find out the suitable substrates composition for biogas production.

Jhelum is the main source of livelihood in the valley. It has been marred by extensive siltation in the past few decades. In absence of conservative measures, the river has lost its carrying capacity. The routing capacity of the Flood Spill Channel which starts from Padshahi Bagh and flows in Srinagar outskirts towards north Kashmir has got reduced to less than 4000 cusecs due to siltation and encroachment over the years. The drainage capacity of the River Jhelum and that of Flood Spill Channel has significantly reduced over time due to massive siltation and because dredging has not kept pace with the rate of siltation . The loss of wetlands that use to absorb water during the floods has resulted in increase in hydrograph peak. As a result Jhelum swells up quickly after just 100mm of rainfall in the catchment, spread over more than 8000 km2. Presently, Jhelum’s maximum water carrying capacity is 60000 cusecs in south Kashmir. In Srinagar city , this capacity is to be restored to 35000 cusecs. The remaining 25000 cusecs is to be diverted through the flood spill channel, whose discharge capacity is also proposed to be increased. As observed in 2014, the discharge recorded in main Jhelum at Sangam was of the order of 1.2 lakh cusecs i.e. double the maximum carrying capacity of river. 60000 cusecs can be mitigated only when spill channel from Padshahibagh to Sopore could carry 25000 cusecs.and main River course, especially through Srinagar city, could take 35000 cusecs. The mitigation of balance 60000 cusecs is the burning problem. Studies on strategic flood management of river Jhelum through tunnel from Dogripora (sangam) to czhal (boniyar) in the State of Jammu and Kashmir, India as an alternative has been considered in the current studies. From the conclusion, it can be ascertained that a extra quantum of water can easily be diverted and floods like 2014 can be avoided

All the previous studies on buckling and postbuckling loads of plate having all four edges simply supported (SSSS) have been limited to the use of assumed double trigonometric functions of displacement and stress. This has constrained further studies on practical plates’ problems, as the buckling and postbuckling load equation derived thereafter by this approach lacked practical interpretation and application because major associated parameters such as the displacement parameter, Wuv, stress coefficient, Wuv2 and load factor, Kcx were not determined. Hence, this paper obtained the displacement and stress functions of buckling and postbuckling loads of SSSS plate by applying the direct integration theory to the Kirchhoff’s linear buckling governing differential equation and Von Karman’s non–linear governing differential compatibility equation consecutively. Work principle was applied to the Von Karman’s non–linear governing differential equilibrium equation to obtain the buckling and postbuckling loads of the plate. Yield/maximum stress of the plate was also obtained by imposing the bending stress influences of the in-plane loads on their direct stress influences. Wuv, Wuv2 and Kcx were also defined. Therefore, the buckling/postbuckling load and critical yield stress characteristics of SSSS plate under uniformly distributed uniaxial loads could be analyzed completely.

Generally the soil quality improvements through stabilization include better soil gradation, reduction of plasticity index or swelling potential, and increases in durability and in strength. The tensile strength and stiffness of a soil layer can be improved through the use of additives and thereby permit a reduction in the thickness of the stabilized layer and overlying layers within the pavement system. According to Sherwood (1995) and Little (1999), lime stabilization can be used to either modify or stabilize clays. The strength of lime mixture depends to a great extent on the quantity of lime added above lime fixation point. (i.e. it changes the Plasticity Index of soil). In this experiment Indian A-7a type black cotton sol is used. In this paper soil subgrade characteristics are determined by using 0%, 3%, 6%, 9%, 12%, lime ( by weight of soil) stabilization techniques & a graphical representation is made % of stabilization Vs PI values. So gradually PI value of soil decreases. But some time in the field plasticity of soil, especially black cotton soil changes very rapidly in this case the advantage of this graph is one can easily get some rough idea about changes soil characteristics due to applications of lime stabilization, when the soil becomes highly plastic to non plastic. Finally a semi empirical formula is made to get an idea about Plastic Index value of A-7a type black cotton soil (As per Highway Research Board of India) due to application of lime stabilization within range of 0 to 12% of lime by weight of soil. This paper also help full to determine how the subgrade strength varies with lime stabilization.

self compacting concrete, also referred as self-consolidate concrete, is able to flow in and consolidate under its own weight and is almost completely while flowing in all type of formwork. It is cohesive enough to fill the spaces of almost any size and shape without any segregation and bleeding. This makes SCC particularly useful wherever placing is difficult, such as in heavily –reinforced concrete members or in complicated work forms. In this study it is proposed to place the constituent material by mineral admixtures and adding chemical admixtures. Also, it is proposed to use self curing compound instead of normal curing concrete. Self compacting and self curing concrete specimens in size of cubes (150mmx150mm x150mm), cylinder (300mm x150mm), and prisms (500mm x 100mmx100mm) were cast and tested. The ANN modeling also derives and compares the results.