Effects of Environmental conditions are a challengingand tedious task and the designer would encounter extreme problems in thefoundation of bridges.
The most crucial factor that may control the design ofbridges over water is environmental conditions rather than ground conditionunlike the design of bridge foundation on land which is govern by groundcondition discarding the environmental factors leads to the collapse of bridgesenvironmental factors that can influence thelife expectancy of the bridge Therefore, it is considerably significant to understand theenvironmental conditions that over bridge designsuch as soil factor, calamity factors, land type, light affecting the arena. Inthis paper the review of 7 papers is described with their all aspects in thearea of civil engineering. Keywords –DC motor, ATMELmicrocontroller, Metro train, Motor driver IC I. INTRODUCTION Thefast growth of populations has created new needs for mobility and increased thedemands for constructing efficient bridges.
The growth in bridge constructionhas been very progressive in many countries around the world over the lastdecades. Many great bridges have been built successfully while others has not,Thus, building on an extensive knowledge to design, plan, construct and manageefficient bridge construction will contribute to mobility that is safe andreliable with a minimum impact on the environment. In spite the fact thatbridge construction has experienced positive development trends compared to thepast years.
The interrelation of effectivenessparameters, geographical areas, time span and disciplines are monitories belowis the stat for the survey in different geographical view of site or indifferent geographical arenas.As it has been mentioned, severalresearchers who viewed different sites represented that are involved in thebridge construction processes. Also there are several effectiveness wereconsidered by these researchers. It is amazed to see if this has any influenceon the successful bridge construction. On the other hand, in order to draw aholistic view over that, it is initially important to analytic judgment theseparameters more critically with regard to their geographical differences II. PROBLEMSTATEMENT Thereare several natural factors which also affects the bridge formation like landscape,river valleys, soil rigidity and sunlight. A. LANDSCAPEA landscape is the visible features of an area of land, its landforms and how theyintegrate with natural or man-made features, A landscape includes the physicalelements of geophysically defined landformssuch as (ice-capped) mountains,hills, water bodies such as rivers, lakes, ponds and the sea, living elements of land cover includingindigenous vegetation,human elements including different forms of land use, buildings and structures, and transitory elements such as lighting and weather conditions.
Regionaldifferences are also very important in considering landscape needs. Irrigationis often the major concern in terms of management and the expense of repairsand upgrades. In markets with expensive land, not enough room for trees is animportant consideration. B.
SUNLIGHTCold weather can affectconstruction adversely, hence it is always advisable to take initial and importantprecautions to combat these effects. It is advisable to follow the buildingcodes Perhaps the most critical factor in construction operations carried outin cold weather is ensuring that mortar and grout get adequate heat for normalcement hydration. Lower temperatures either completely stop or slow down theprocess of cement hydration due to lack of heat, which reduces the masonry’sbond strength. Frozen masonry units must be melted and dried before implementingthem in use. Measure the unit temperature using a metallic surface contactthermometer or flat, instant-read thermometer. It is advisable to heat brickseven when ambient temperatures are above 20 ºF (-6.7 ºC). Preheated brick willhave the same absorption characteristics as that laid at normal temperatures.
It is important to protect mortar fromfreezing temperatures. A frozen mortar mill significantly reduces thecompressive strength (concise strength), the bond strength and also decreasethe water penetration resistance of masonry. Also, mortar with water contentmore than six percent of the total volume may be damaged, as the frozen ice maymelt to increase its volume thereby reducing its bond strength.Consider alteration of mortar constituents and proportions within the possiblerange to reduce the impact of cold weather. Also increasing the sand contentcan give a stiffer mortar mixture.
Using lime content will allow mortar to lossof water easily. Figure.3. Sunlight C.
SOIL RIGIDITYWhen soft to firm, clay canexhibit large settlements under load. These settlements are likely tooccur slowly due to clay’s poor drainage characteristics. Pore pressureswithin the clay particle spaces move slowly, leading to long-term consolidationsettlement. Regionally, different clays exhibit different and unique properties.Swelling clay exists in many areas (particularly throughout the PrairieProvinces). This clay can shrink or swell upon changes in moisture content.This can lead to subsidence or settlement. Soil heave is also an issuewhen it comes to clay, and swelling clay in particular, having the potential topush the foundation and the structure above upwards.
Sandysoil has naturally shifting characteristics; drainage through sandy soilfurther increases its shifting properties. This poses a clear challenge for anystructures being built on this type of soil. Loose sand can be subject to largesettlements, and these settlements tend to occur quickly due to thefree-draining granular nature of sands. This can pose foundationchallenges and loose sand requires densification in order to provide sufficientsettlement control and bearing for new structures.Strengthof stress factor for soil with respect to different materials is representedgraphically below-*soil-soil*soil-concrete*soil-steelFigure.
3. Soilfactor D. RIVER VALLYESRock for river valleys is one ofthe oldest constructional material known to man, and yet only, till recentlyvery little was known about its structural behavior.
The increasing size ofloads imposed on rock foundations has caused disastrous failures. In the designof structures to be founded on the rock, it is necessary to recognize that thefoundation rock has definite limitations when used as an engineering material.The structurefoundation bearings and grinders may not be visible. Bridges span over gaps interrain or earth surface ,such as gorges formed due to river valleys andnatural cavity in topography.Below are some types of river valley pictorial views Figure.3.
Rivervalley III. LITRATURE REVIEW IV. CONCLUSIONIn case of every wide range construction project,there are always some environmental impacts on the surrounding of the site Thispaper is useful in developing projects & enhancing the construction field whichhas a bright future as these factors are being used in countries like UAE, France& USA. This paper work also helps in increase the number of projects thatcannot be performed successfully.
By implementing these useful plan and designit is possible to construct environment friendly infrastructures, protectbiodiversity and vegetation and also to the proper control of economy, agriculture,transport and land management. Floods, riverbank erosion, settlementdisplacement and char livelihoods problems will be minimized, and make theisland stable. This work will lead to increase in technological trends. Now ourmain aim is to implement environmental laws for the successful construction ofstructures.