Seismic Behavior Of Isolated Bridges ( CIVIL )

ABSTRACT:
Bridges are lifeline structures. They act, as an important link in surface transportation network and failure of bridges during a seismic event will seriously hamper the relief and rehabilitation work. There are many cases of damage of bridges in the past earthquakes all over the world. Due to their structural simplicity, bridges are particularly vulnerable to damage and even collapse when subjected to earthquakes. The fundamental period of vibration of a majority of bridges is in the range of 0.2 to 1.2 second. In this range, the structural response is high because it is close to the predominant periods of earthquake-induced ground motions. The seismic forces on the bridges can be reduced if the fundamental period of the bridge is lengthened or the energy dissipating capability is increased. Therefore, the seismic isolation is a promising alternative for earthquake-resistant design of bridges. Considerable efforts have been made in the past two decades to develop improved seismic isolation design procedure for new bridges and comprehensive retrofit guidelines for existing bridges. One of the goals of the seismic isolation is to shift the fundamental frequency of a structure away from the dominant frequencies of earthquake ground motion and fundamental frequency of the fixed base superstructure. The other purpose of an isolation system is to provide an additional means of energy dissipation, thereby reducing the transmitted acceleration into the superstructure. The suitability of a particular arrangement and type of isolation system will depend on many factors including the span, number of continuous spans, and seismicity of the region, frequencies of vibration of the relatively severe components of the earthquake, maintenance and replacement facilities.  

Engineering Aspects Of Reinforced Soil ( CIVIL )

ABSTRACT:
Reinforced soil is composite material which is formed by the associating of frictional soil and tension resistant elements in the form of sheets, strips, nets or mats of metal, synthetic fabrics or fibre reinforced plastics and arranged in the soil mass in such a way as to reduce or supress the tensile strain which night develop under gravity and boundary forces. It is well known that most granwar soils are strong in compression and shear and weak in tension. The performance of such soils can be improved by introducing reinforcing elements in the direction of tensile straine in the same way as in reinforced concrete.
The variety and range of application of reinforced soil is unlimited severs field applications include retaining walls, abutments, away walls, embankments dams, hill roads, housing, foundations, railways, industry, pipe works, waterway structure and under ground structures.
The soil reinforcement technique results in
(i) a simple , composite material, quick and easy to make
(ii) a flexible material, able to withstand important deformation without damage.
(iii) A heavy material both from the technical and architectural paint of view and
(iv) An economical material.
These merits of reinforced soil enabled its use in almost all civil engineering structures. 

Mobile Inspection Platform ( CIVIL )

ABSTRACT:
There is a need for reliable and economic Mobile Inspection Platform (MIP) for the inspection of Bridges. We have in our country, a large number of road bridges. Every year new road bridges are added to the existing bridges. The older bridge require maintenance to continue to permit serviceability. For proper maintenance, assessment is to be done. Inspection for assessment is to be done not only from the top of the carriageway, but also from the side and bottom of the deck, and also around the sub-structure. The MIP provides a very economic and convenient means of producing such inspection data. Minor maintenance can also be carried out using MIP... . 

Superplasticisers For Ready Mix Concrete Plants ( CIVIL )

ABSTRACT:

Superplasticisers are high range water reducing admixtures..Admixture is defined as a material other than cement ,water and aggregate that is used as an ingredient of concrete and is added to the batch immediately before or during mixing. The development of superplasticisers is one the major break throughs in concrete technology, which will have a significant effect on the production and use of concrete in the next millennium. Superplasticisers have been greatly responsible for development of the following connects.
1) High performance connects
2) High strength concrete
3) High durability concrete
4) Self compacting concrete
5) High volume flyash /slag concrete
6) Fibre reinforced concrete
7) Anti washout concrete under water.

A superplasticiser is one of a class of admixtures called water reducers that are use to lower the mix water requirement of the concrete. They are chemically different from normal water reducers and are capable of reducing water contents by about 30 percent. They are variously known as superplasticisers, super fluidizers , superfluidifiers, super water reducers or high range water reducers. In Japan, during the late 1960’s superplasticisers were developed. Ready mix concrete incorporating water reducers and workability enchancers make use of superplasticisers and delivers increased workability without loss of ultimate strength or durability. The role of superplasticisers in ready mix concrete industry is essential where ordinary as well as high strength or high performance concrete with slump retention capability are to be produced. Superplasticisers can be used to reduce the amount of water to produce high strength concrete and to reduce the amount of cement.

Evacuation Patterns In High Rise Buildings ( CIVIL )

ABSTRACT:
This topic deals with the evacuation pattern in high rise buildings mainly on the onset of fire.The ability to warn population of the impending disasters has become a reality only in the last few years. The ability to track and warn must be complimented with the capability of effecting a timely evacuation of potentially threatened areas. The two problems that exist are the ability to adequately disseminate a warning of an impending disaster and that of producing an evacuation once the warning has been received. These problems can be overcome by the development of a timely and accurate warning system, identification of escape routes, and establishment of a policy wherein every one within a threatened area is required to evacuate when an order is given... . 

Plastic As Soil Stabilizer ( CIVIL )

ABSTRACT:
Use of plastic products such as polythene bags,bottles, containers and packing strips etc. is increasing day by day. As a result amount of waste plastic also increased. This will leads to various environmental problems. Many of the wastes produced today will remain in the environment for many years leading to various environmental concerns. Therefore it is necessary to utilize the wastes effectively with technical development in each field. Many by-products are being produced using the plastic wastes. This paper presents the details of studies, conducted by various researchers on the possible use of waste plastic for soil stabilization. The results of the studies indicate that by adding plastic strips in soil; shear strength, tensile strength and California bearing ratio (CBR) value of the soil increases. . 

Thermal Expansion Of Concrete ( CIVIL )

ABSTRACT:
Concrete structures and its members are underconstant multi-axial stress and exposed to various temperatures. The purpose of this study is to clarify the thermal expansion of plain concrete under constant multi-axial stress. The thermal expansion of concrete between 20C and 100C, under constant compressive stress including tri-axial loading can be concluded to be equal to the sum of elastic deformation caused by external forces, the thermal expansion without external load and creep strain. The thermal expansion of air dried concrete and water saturated concrete is smaller than the thermal expansion of pre-heated concrete.. . 

Application Of Large Deformation Analysis In Soil Mechanics ( CIVIL )

ABSTRACT:

In soil mechanics, the material nonlinearity and itscomputer implementation in the finite element (FE) analysis have been treated in great efforts. However, significantly less effort has been spent on introducing the equally important concepts of finite strain/large deformation in soil mechanics, despite the fact that the effect of deformation upon the overall geometry of structures may not be ignored in many geotechnical engineering problems.

The application of large deformation analysis in two soil mechanics problems will be presented. One is a rigid footing penetrating into two-layered clay, and the other is a fully-bonded anchor lifted up in a homogeneous clay.
The load - displacement curves and the bearing or uplift capacity factors predicted by the large deformation analysis are given. The effect of large deformation is discussed based on comparing the small and large deformation analysis results. Unlike the small deformation analysis of cohesive soil, it is found that in large deformation analysis, the soil self-weight can have a significant effect on the load-displacement behaviour.. . 

FENG SHUI AND VAASTU SHASTRA ( CIVIL )

                                                            ABSTRACT :




The name Feng shui is derived from two words, which are “Feng” and “shui”. Feng means "wind," and shui means "water" (pronounced fung-shway). In Chinese culture, gentle wind and smooth water have always been associated with a good harvest and good health, while harsh winds and stagnant water have been linked to famine and disease. Therefore, "good" feng-shui has come to mean good livelihood and fortune, and "bad" Feng-shui has come to mean hardship and misfortune.
            Feng shui is the chinese art of placement which helps us to create harmony, balance the positive energy in our environment through the proper use of furnishing, art, mirror, objects, plants and all others around and in our environment. Positive energy is created in our environment by work with the natural flow of energy. 

REACTIVE POWDER CONCRETE ( CIVIL )

                                                                 ABSTRACT:


Reactive Powder Concrete is a developing composite material that will allow the concrete industry to optimize material use, generate economic benefits and build structures that are strong, durable and sensitive to environment.RPC is an ultra high strength and high ductility cementitious composite with enhanced physical and mechanical properties. It was first developed in the early 1990’s by Bouygue’s laboratory in France. It consists of a special concrete where its microstructure is optimized by precise gradation of all particles in the mix to yield maximum density. At the level of maximum compressive strength of concrete, the coarse aggregate becomes the weakest link in concrete. In order to increase the compressive strength of concrete even further, the only way is to remove the coarse aggregate. This philosophy has been employed in RPC. It is a material which can resist direct primary tensile stresses and having the potential to structurally compete with steel.