Search results. 5 results for Books: "caite.info" Bridge Tunnel and Railway Engineering. by S.P. Principles and Practices of Bridge Engineering. A Text- Book Of Hydrology And Water Resources by R. K. Sharma, A Text - Book Of Railway Engineering by S. C. Saxena, S. P. Arora, Tunnel Engineering by. Railway bridge tunnel engineering amtrak train in autumn landscape amtrak train in Bridge Tunnel And Railway Engineering By S P Bindra.
|Language:||English, Spanish, Hindi|
|Genre:||Science & Research|
|ePub File Size:||21.51 MB|
|PDF File Size:||18.57 MB|
|Distribution:||Free* [*Regsitration Required]|
S.P. Bindra is the author of Bridge Tunnel and Railway Engineering ( avg rating, 16 ratings, 0 reviews) and Principles and Practices of Bridge Engine. Buy Principles and Practices of Bridge Engineering eBook By S P Bindra PDF Online from Dhanpat Rai Publications. Download Free Sample and Get Upto 73 %. A TEXT BOOK OF CIVIL ENGINEERING MATERIALS. S. P. Arora. 1. Preamble 2. . ELEMENTS OF BRIDGE, TUNNEL & RAILWAY ENGINEERING S.P. Bindra.
Some of the many elements of highway design are a. So the alignment may be deviated not to pass through that point. Please enter your name here. Pavement surface characteristics For a safe and comfortable driving four aspects of the pavement surface are important; the friction between the wheels and the pavement surface, smoothness of the road surface, the light re ection characteristics of the top of pavement surface, and drainage to water. Bitumen Overview Bituminous materials or asphalts are extensively used for roadway construction. Critical load positions There are three typical locations namely the interior.
The earliest authentic record of road was found from Assyrian empire constructed about BC. In this section we will see in detail about Ancient roads. To provide adequate strength to carry the wheels. It is used for the smooth conveyance of both people and goods. Roads in Rome were constructed in a large scale and it radiated in many directions helping them in military operations.
The roads were bordered on both sides by longitudinal drains. Thus they are considered to be pioneers in road construction. These human pathways would have been developed for specific purposes leading to camp sites.
This was a raised formation up to a 1 meter high and 15 m wide and was constructed with materials excavated during the side drain construction. This created major drainage problems which were counteracted by making the surface as impervious as possible.
All this structure was placed in a trench in order to keep the running surface level with the surrounding country side. French roads 2. Finally the running layer was made with a layer of 25 mm sized broken stone.
Smaller pieces of broken stones were then compacted into the spaces between larger stones to provide a level surface. He developed a cheaper method of construction than the lavish and locally unsuccessful revival of Roman practice. The pavement used mm pieces of quarried stone of a more compact form and shaped such that they had at least one at side which was placed on a compact formation. Thus concrete was a major Roman road making innovation. Stone size was an important element of Macadam recipe.
Many easily and locally available materials are tested in the laboratories and then implemented on roads for making economical and durable pavements.
The construction of Grand-Trunk road connecting North and South is a major contribution of the British. A typical cross section of British roads is given in Fig. Macadam introduced what can be considered as the first scientific road construction method. During the time of Mughal period. Roads linking North-West and the Eastern areas through gangetic plains were built during this time.
So need for better roads became a necessity. By empirical observation of many roads. Jayakar as the chairman. Thus he introduced an economical method of road construction. Use of bituminous concrete and cement concrete are the most important developments. For that. British roads 2.
Road Development in India Excavations in the sites of Indus valley revealed the existence of planned roads in India as old as BC. This committee came to be known as Jayakar committee. The Mauryan kings also built very good roads. Development of new equipments helps in the faster construction of roads. The committee planned to construct 2 lakh kms of road across the country within 20 years.
This led to the introduction of a development fund called Central road fund in According to the importance. The roads were divided into four classes: The major recommendations and the resulting implementations were: It was the first attempt to prepare a co-ordinated road development programme in a planned manner.
This fund was intended for road development. Nagpur road congress A twenty year development programme for the period was finalized.
Jayakar Committee In Jayakar committee for Indian road development was appointed. Lucknow road congress Some of the salient features of this plan are as given below: Accordingly a year plan was drafted by the Roads wing of Government of India. The highlights of the plan were: Although National Highways constitute only about 2 per cent of the road network. One of the objective was that the road length should be increased so as to give a road density of 16kms per sq. It is also called Lucknow road plan.
The rapid expansion and strengthening of the road network. Road transport also acts as a feeder service to railway. Easy availability. The number of vehicles has been growing at an average pace of around 10 per cent per annum. The share of road traffic in total traffic has grown from This problem definition occurs at the State. It is during the first three stages. After construction is completed. In fact. During planning. Existing or projected future travel demands exceed available capacity.
The level of environmental review varies widely. The route is experiencing an inordinate number of safety and accident problems that can only be resolved through physical. The problems identified usually fall into one or more of the following four categories: It can range from a multiyear effort to prepare an Environmental Impact Statement a comprehensive document that analyzes the potential impact of proposed alternatives to a modest environmental review completed in a matter of weeks.
Regardless of the level of detail or duration. At this stage. Developmental pressures along the route make a reexamination of the number.
For example. Integrating all these elements to achieve a common goal or concept helps the designer in making design decisions. Number and width of travel lanes. The cross section can include a clear zone. Limiting the width of pavement or breaking up the pavement is one option. The design element with the greatest effect on the scale of the roadway is its width.
The product of this stage is a complete set of plans. This large discrepancy in the design scale for a car versus the design scale for people has changed the overall planning of our communities.
There are many elements in a highway. The wider the overall roadway. Depending on the scale and complexity of the project. Some of the many elements of highway design are a. The following paragraphs discuss some important considerations of design.
Project Development The transportation project is more clearly defined. Employing a multidisciplinary design team ensures that important design details are considered and those they are compatible with community values. Design The design team develops detailed design and specification.
And Maintenance Once the final designs have been prepared and needed right-of-way is purchased. Stages Planning Description of Activity Identification of transportation needs and program project to be built Within financial constraints. Once construction has been completed. In some instances. During the right-of-way acquisition and construction stages. Even after the completion of construction.
A multidisciplinary design team can produce an aesthetic and functional product when the members work together and are flexible in applying guidelines.
Construction may be simple or complex and may require a few months to several years. Alternative locations and design features are developed and an alternative is selected. Right-of-way Land needed for the project is acquired.
Often it is the details of the project that are most recognizable to the public. Drainage Studies o Surface run. A variety of survey and investigations have to be carried out by Road engineers and multidiscipline persons.
Pavement Design investigation Soil property and strength. Hydrologic and hydraulic o Subsurface drainage: Location and waterway area required for the cross-drainage structures.
The features normally considered are the cross section elements. Cross-section elements including cross slope. The geometric design of highways deals with the dimensions and layout of visible features of the highway.
These basic elements are common to all linear facilities. This chapter focuses on the fundamentals of geometric design. Sight distance elements including cross slope. The planning cannot be done stage wise like that of a pavement. Factors affecting the geometric design. Highway alignment.
The design of these features is to a great extend influenced by driver behavior and psychology. Vertical alignment and its components like gradient. Proper geometric design will help in the reduction of accidents and their severity.
Horizontal alignment which includes features like super elevation. Overview Geometric design for transportation facilities includes the design of geometric cross sections.
Intersection features like layout. The main components that will be discussed are: Pavement surface characteristics. In all cases. Although the details of design standards vary with the mode and the class of facility. The general unit for measuring traffic on highway is the Annual Average Daily Traffic volume. The environmental factors like air pollution. Since the speed of vehicles vary with driver.
Freeways are access controlled divided highways. It will be uneconomical to design the roadway facilities for the peak traffic flow. The traffic flow or volume keeps fluctuating with time. It is easier to construct roads with required standards for a plain terrain. Traffic volume indicates the level of services LOS for which the highway is being planned and directly affects the geometric features such as width. It is of crucial importance in highway design.
Note that as the accessibility of road increases. Access is controlled through the use of interchanges.
It directly affects the sight distance. See Fig. Design speed is the single most important factor that affects the geometric design. Most freeways are four lanes. The classification based on speed and accessibility is the most generic one. It is a general term denoting a street primarily meant for through traffic usually on a continuous route.
Rural highways are those passing through rural areas villages and urban highways are those passing through large cities and towns. These are streets intended for collecting and distributing traffic to and from local streets and also for providing access to arterial streets.
A local street is the one which is primarily intended for access to residence. They are generally provided with grade separations at intersections. Highways are of two types. Normally full access is provided on these streets. It does not normally carry large volume of traffic and also it allows unrestricted parking and pedestrian movements. They are generally divided highways with fully or partially controlled access. They represent the superior type of roads in the country.
There are few parking restrictions except during peak hours. Water bound macadam WBM. Roads which are not provided with a bituminous or cement concreting surface are called unsurfaced roads. Based on usage This classified is based on whether the roads can be used during di erent seasons of the year. Those roads which are negotiable during all weathers. Based on the traffic volume. Based on carriage way This classification is based on the type of the carriage way or the road pavement.
Based on pavement surface Based on the type of pavement surfacing provided. Thus earth and gravel roads come under this category. These terms are relative and so the limits under each class may be expressed as vehicles per day. Other criteria Roads may also be classified based on the traffic volume in that road.
Roads which are negotiable only during fair weather are called fair weather roads. Roads which are provided with a bituminous or cement concreting surface are called surfaced roads.
Roads which are not provided with a hard course of atleast a WBM layer they is called unpaved roads. Bituminous macadam BM. Roads can be classified based on some other criteria. If they are provided with a hard pavement course such roads are called paved roads. They are given in detail below. Based on the load carried by these roads. Horizontal alignment includes straight and curved paths. It should be easy for the operation of vehicles. Factors controlling alignment We have seen the requirements of an alignment.
The various factors that control the alignment are as follows: These are the control points governing the highway alignment. It should have safe geometric features. These points are classified into two categories. So to the maximum extend easy gradients and curves should be provided. The highway alignment can be either horizontal or vertical and they are described in detail in the following sections. Once an alignment is xed and constructed.
The classification based on location and function should be a more acceptable classification since they may be defined clearly. Alignment decision is important because a bad alignment will enhance the construction. But it is not always possible to satisfy all these requirements. Thus to locate a bridge the highway alignment may be changed. Vertical alignment includes level and gradients. The road approach to the bridge should not be curved and skew crossing should be avoided as possible.
Points through which it should pass and points through which it should not pass. Hence we have to make a judicial choice considering all the factors. Some of the examples are: The bridge can be located only where the river has straight and permanent path and also where the abutment and pier can be strongly founded.
The new alignment should be drawn keeping in view the desire lines. The alignment may be slightly deviated to connect an intermediate town or village nearby. To keep the radius of curve minimum. The presence of a lake or pond on the alignment path would also necessitate deviation of the alignment.
The alignment should suit the traffic requirements. The alignments should be finalized such that the obstructions to visibility do not restrict the minimum requirements of sight distance. The suitability of the alternative depends on factors like topography. These were some of the obligatory points through which the alignment should pass.
The design standards vary with the class of road and the terrain and accordingly the highway should be aligned. Geometric design factors such as gradient.
While the alignment passes through a mountain. Acquiring such structures means heavy compensation which would result in an increase in initial cost. Coming to the second category that is the points through which the alignment should not pass are: These have been protected by the law from being acquired for any purpose.
So the alignment may be deviated not to pass through that point. Based on the origindestination data of the area. Lecture 5 Cross sectional elements 5. Details vary depending on the type of facility Highway cross sections consist of traveled way, shoulders or parking lanes , and drainage channels.
Shoulders are intended primarily as a safety feature. They provide for accommodation of stopped vehicles, emergency use, and lateral support of the pavement. Shoulders may be either paved or unpaved. Drainage channels may consist of ditches usually grassed swales or of paved shoulders with berms or curbs and gut-ters. Cross section of various roads are given bellow.
Pavement surface characteristics For a safe and comfortable driving four aspects of the pavement surface are important; the friction between the wheels and the pavement surface, smoothness of the road surface, the light re ection characteristics of the top of pavement surface, and drainage to water. Friction Friction between the wheel and the pavement surface is a crucial factor in the design of horizontal curves and thus the safe operating speed.
Further, it also a ect the acceleration and deceleration ability of vehicles. Lack of adequate friction can cause skidding or slipping of vehicles. Skidding happens when the path traveled along the road surface is more than the circumferential movement of the wheels due to friction Slip occurs when the wheel revolves more than the corresponding longitudinal movement along the road. Various factors that a ect friction are: The frictional force that develops between the wheel and the pavement is the load acting multiplied by a factor called the coe cient of friction and denoted as f.
The choice of the value of f is a very complicated issue since it depends on many variables. IRC suggests the coe cient of longitudinal friction as 0. The former is useful in sight distance calculation and the latter in horizontal curve design. Unevenness It is always desirable to have an even surface, but it is seldom possible to have such one. Even if a road is constructed with high quality pavers, it is possible to develop unevenness due to pavement failures.
Unevenness a ect the vehicle operating cost, speed, riding comfort, safety, fuel consumption and wear and tear of tyres.
Unevenness index is a measure of unevenness which is the cumulative measure of vertical undulation of the pavement surface recorded per unit horizontal length of the road. Light refleection Drainage The pavement surface should be absolutely impermeable to prevent seepage of water into the pavement layers. Further, both the geometry and texture of pavement surface should help in draining out the water from the surface in less time. Camber Camber or cant is the cross slope provided to raise middle of the road surface in the transverse direction to drain o rain water from road surface.
Too steep slope is undesirable for it will erode the surface. Width of carriage way Width of the carriage way or the width of the pavement depends on the width of the traffic lane and number of lanes.
Width of a traffic lane depends on the width of the vehicle and the clearance. Side clearance improves operating speed and safety. Kerbs Kerbs indicate the boundary between the carriage way and the shoulder or islands or footpaths.
Di erent types of kerbs are Figure Road margins The portion of the road beyond the carriageway and on the roadway can be generally called road margin. Various elements that form the road margins are given below. Lecture 6 Sight distance Overview Sight Distance is a length of road surface which a particular driver can see with an acceptable level of clarity.
Sight distance plays an important role in geometric highway design because it establishes an acceptable design speed, based on a driver's ability to visually identify and stop for a particular, unforeseen roadway hazard or pass a slower vehicle without being in conflict with opposing traffic.
As velocities on a roadway are increased, the design must be catered to allowing additional viewing distances to allow for adequate time to stop. Reaction time of the driver 2. Speed of the vehicle 3.
Efficiency of brakes PIEV Process The perception-reaction time for a driver is often broken down into the four components that are assumed to make up the perception reaction time. These are referred to as the PIEV time or process. Stopping sight distance Stopping sight distance is defined as the distance needed for drivers to see an object on the roadway ahead and bring their vehicles to safe stop before colliding with the object. The factors that affect the OSD are: A roadway designed to criteria employs a horizontal and vertical alignment and a cross section that provides at least the minimum stopping sight distance through the entire facility.
Overtaking sight distance The overtaking sight distance is the minimum distance open to the vision of the driver of a vehicle intending to overtake the slow vehicle ahead safely against the traffic in the opposite direction. The overtaking sight distance or passing sight distance is measured along the center line of the road over which a driver with his eye level 1. The stopping sight distance is comprised of the distance to perceive and react to a condition plus the distance to stop: Safety II.
Construction costs Operating speed is influenced by all other factors so it is the critical factor to consider. Design speed IV. For proper design of the curve. The design speed also depends on the type of the road.
Grades III. For e. Centrifugal force depends on speed and radius of the horizontal curve and is counteracted to a certain extent by transverse friction between the tyre and pavement surface. Cost of resumption of land V. The horizontal curve design elements include design of super elevation. Horizontal alignment design involves the understanding on the design aspects such as design speed and the effect of horizontal curve on the vehicles. Design Speed The design speed as noted earlier.
Horizontal curve The presence of horizontal curve imparts centrifugal force which is reactive force acting outward on a vehicle negotiating it. Lecture 7 Horizontal alignment I Overview Horizontal alignment is one of the most important features influencing the efficiency and safety of a highway.
On a curved road. Factors Affecting Alignment I. At equilibrium. W the weight of the vehicle acting down-wards through the center of gravity. A brief discussion about pavement widening at curves is also given. Elimination of the crown of the cambered section by: Rotation of the pavement cross section to attain full super elevation by: There are two methods of attaining superelevation by rotating the pavement rotation about the center line: For slow moving vehicles.
Lecture 8 Horizontal alignment II Overview This section discusses the design of superelevation and how it is attained. Some extra space is to be provided for more clearance for the crossing and overtaking operations on curves. In addition. Setting out large curves in the field becomes difficult. This widening is done due to two reasons: Mechanical widening The reasons for the mechanical widening are: When a vehicle negotiates a horizontal curve.
The radius of the horizontal curve is an important design aspect of the geometric design. Although it is possible to design the curve with maximum superelevation and coe cient of friction.
There is a tendency for the drivers to drive close to the edges of the pavement on curves. Extra widening Extra widening refers to the additional width of carriageway that is required on a curved section of a road over and above that required on a straight alignment. The maximum comfortable speed on a horizontal curve depends on the radius of the curve.
The need for Transition Curves Circular curves are limited in road designs due to the forces which act on a vehicle as they travel around a bend. Composite curves. Transition curve ensures a smooth change from straight road to circular curves. Lecture 9 Horizontal alignment III Overview In this section we will deal with the design of transition curves and setback distances.
Setback distance looks in for safety at circular curves taking into consideration the sight distance aspects.
This increases the comfort of passengers. Transition curves have much more complex formulae and are more difficult to set out on site than circular curves as a result of the varying radius. As one would expect. The use of Transition Curves Transition curves can be used to join to straights in one of two ways: Horizontal Transition Curves A transition curve differs from a circular curve in that its radius is always changing.
Transition curves are used to introduce those forces gradually and uniformly thus ensuring the safety of passenger. Types of Transition Curve There are two types of curved used to form the transitional section of a composite or wholly transitional curve. Rate of introduction of super-elevation 3. Curve Resistance When the vehicle negotiates a horizontal curve. The setback distance depends on: Rate of change of centrifugal acceleration 2.
Length of transition curve The length of the transition curve should be determined as the maximum of the following three criteria: By empirical formula Setback Distance Setback distance m or the clearance distance is the distance required from the centerline of a horizontal curve to an obstruction on the inner side of the curve to provide adequate sight distance at a horizontal curve.
The front wheels are turned to move the vehicle along the curve. These are: The former is called a summit curve. While aligning a highway. Before nalizing the gradients. Usually steep gradients are avoided as far as possible because of the difficulty to climb and increase in the construction cost.
Vertical alignment is documented by the profile. Gradient Gradient is the rate of rise or fall along the length of the road with respect to the horizontal. Lecture 10 Vertical alignment-I Overview The vertical alignment of a transportation facility consists of tangent grades straight lines in the vertical plane and vertical curves. The deviation angle N is: When these two curves meet.
Just as a circular curve is used to connect horizontal straight stretches of road. Due to restrictive sight distance at uphill gradients the speed of traffic is often controlled by these heavy vehicles. Effect of gradient The effect of long steep gradient on the vehicular speed is considerable. This is particularly important in roads where the proportion of heavy vehicles is significant.
As a result. More about gradients are discussed below. On the contrary. They are formed when two gradients meet. Lecture 11 Vertical alignment-II Overview Valley curve Valley curve or sag curves are vertical curves with convexity downwards. They are formed when two gradients meet in any of the following four ways: When an ascending gradient meets another ascending gradient.
When a descending gradient meets another descending gradient. When a descending gradient meets an ascending gradient. Design considerations Thus the most important design factors considered in valley curves are: Safety criteria. Comfort criteria. Types of volume measurements I. Flow There are practically two ways of counting the number of vehicles on a road. Time headway The microscopic character related to volume is the time headway or simply headway.
Time-space diagram Fig. Distance headway Another related parameter is the distance headway. When more and more vehicles are added. When the density is zero. There will be some density between zero density and jam density. At jam density. This is referred to as the jam density or the maximum density. The most simple assumption is that this variation of speed with density is linear Fig. Even if road and vehicles could be set up in large laboratories.
Bindra, is a comprehensive book for Civil Engineering students. It comprises of topics like: Dhanpat Rai Publications is a promising Indian publishing house which has been developing and publishing quality books for school students and other academic books.
Their educational books conform to the latest syllabus and exam patterns prescribed by various universities. The books published by them are compiled and authored by the experts in their respective fields. A Textbook Class - Certified Buyer , Jalpaiguri. Explore Plus. Enter pincode. Usually delivered in days? Bindra S. English Binding: Undefined Publisher: