Unit – 5
ADVANCEMENTS IN CIVIL ENGINEERING
Smart Cities will endeavour to "use technology, information and data to improve infrastructure and services." This includes access to water, electricity, affordable homes, education and health services, and IT connectivity.
Features of Smart Cities
- Adequate water supply,
- Assured electricity supply,
- Sanitation, including solid waste management,
- Efficient urban mobility and public transport,
- Affordable housing, especially for the poor,
- Robust IT connectivity and digitalization,
- Good governance, especially e-Governance and citizen participation,
Solid-waste management, the collecting, treating, and disposing of solid material that is discarded because it has served its purpose or is no longer useful. Improper disposal of municipal solid waste can create unsanitary conditions, and these conditions in turn can lead to pollution of the environment and to outbreaks of vector-borne disease—that is, diseases spread by rodents and insects. The tasks of solid-waste management present complex technical challenges. They also pose a wide variety of administrative, economic, and social problems that must be managed and solved.
Bus rapid transit (BRT), also called a bus way or transit way, is a bus-based public transport system designed to improve capacity and reliability relative to a conventional bus system.[2] Typically, a BRT system includes roadways that are dedicated to buses, and gives priority to buses at intersections where buses may interact with other traffic; alongside design features to reduce delays caused by passengers boarding or leaving buses, or purchasing fares. BRT aims to combine the capacity and speed of a metro with the flexibility, lower cost and simplicity of a bus system.Bus rapid transit takes its name from rail rapid transit, which describes a high-capacity urban public-transit system with its own right of way, multiple-car vehicles at short headways, and longer stop spacing than traditional streetcars and buses. BRT uses buses on a wide variety of rights-of-way, including mixed traffic, dedicated lanes on surface streets, and bus ways separated from traffic.
Typically, a BRT system includes roadways that are dedicated to buses, and gives priority to buses at intersections where buses may interact with other traffic; alongside design features to reduce delays caused by passengers boarding or leaving buses, or purchasing fares.
All passengers uses BRT system because of three main reasons Comfort, Safety and fare. Approach to develop not only dedicated lanes for buses but to provide safe and comfortable corridors for pedestrians, cyclists, motor vehicles etc.
Reduces obesity and health problems by creating safe, accessible and walkable communities. BRT would create pleasant transit stops and safer streets and sidewalks; Provides more frequent, reliable transit to health and medical centers along the corridor.
Rapid transit or mass rapid transit (MRT), also known as heavy rail, metro, subway, tube, U-Bahn, metropolitana or underground, is a type of high-capacity public transport generally found in urban areas. Unlike buses or trams, rapid transit systems are electric railways that operate on an exclusive right-of-way, which cannot be accessed by pedestrians or other vehicles of any sort, and which is often grade-separated in tunnels or on elevated railways.
Modern service on rapid transit systems are provided on designated lines between stations typically using electric multiple units on rail tracks, although some systems use guided rubber tires, magnetic levitation (maglev), or monorail. The stations typically have high platforms, without steps inside the trains, requiring custom-made trains in order to minimize gaps between train and platform. They are typically integrated with other public transport and often operated by the same public transport authorities. However, some rapid transit systems have at-grade intersections between a rapid transit line and a road or between two rapid transit lines.
Metro is the most common term for underground rapid transit systems used by non-native English speakers. Rapid transit systems may be named after the medium by which passengers travel in busy central business districts; the use of tunnels inspires names such as subway
Rapid transit is used in cities, agglomerations, and metropolitan areas to transport large numbers of people often short distances at high frequency. The extent of the rapid transit system varies greatly between cities, with several transport strategies.
Some systems may extend only to the limits of the inner city, or to its inner ring of suburbs with trains making frequent station stops. The outer suburbs may then be reached by a separate commuter rail network where more widely spaced stations allow higher speeds. In some cases the differences between urban rapid transit and suburban systems are not clear.
Rapid transit systems may be supplemented by other systems such as trolleybuses, regular buses, trams, or commuter rail. This combination of transit modes serves to offset certain limitations of rapid transit such as limited stops and long walking distances between outside access points. Bus or tram feeder systems transport people to rapid transit stops.
Each rapid transit system consists of one or more lines, or circuits. Each line is serviced by at least one specific route with trains stopping at all or some of the line's stations. Most systems operate several routes, and distinguish them by colors, names, numbering, or a combination thereof. Some lines may share track with each other for a portion of their route or operate solely on their own right-of-way. Often a line running through the city center forks into two or more branches in the suburbs, allowing a higher service frequency in the center.
Rainwater harvesting is the simple process or technology used to conserve Rainwater by collecting, storing, conveying and purifying of Rainwater that runs off from rooftops, parks, roads, open grounds, etc. for later use.
Rainwater harvesting systems consists of the following components:
- Catchment- Used to collect and store the captured Rainwater.
- Conveyance system – It is used to transport the harvested water from the catchment to the recharge zone.
- Flush- It is used to flush out the first spell of rain.
- Filter – Used for filtering the collected Rainwater and remove pollutants.
- Tanks and the recharge structures: Used to store the filtered water which is ready to use.
The process of rainwater harvesting involves the collection and the storage of rainwater with the help of artificially designed systems that run off naturally or man-made catchment areas like- the rooftop, compounds, rock surface, hill slopes, artificially repaired impervious or semi-pervious land surface.
Several factors play a vital role in the amount of water harvested. Some of these factors are:
- The quantum of runoff
- Features of the catchments
- Impact on the environment
- Availability of the technology
- The capacity of the storage tanks
- Types of the roof, its slope and its materials
- The frequency, quantity and the quality of the rainfall
- The speed and ease with which the Rainwater penetrates through the subsoil to recharge the groundwater.
The rainwater harvesting system is one of the best methods practised and followed to support the conservation of water. Today, scarcity of good quality water has become a significant cause of concern. However, Rainwater, which is pure and of good quality, can be used for irrigation, washing, cleaning, bathing, cooking and also for other livestock requirements.
The benefits of rainwater harvesting system are listed below.
- Less cost.
- Helps in reducing the water bill.
- Decreases the demand for water.
- Reduces the need for imported water.
- Promotes both water and energy conservation.
- Improves the quality and quantity of groundwater.
- Does not require a filtration system for landscape irrigation.
- This technology is relatively simple, easy to install and operate.
- It reduces soil erosion, stormwater runoff, flooding, and pollution of surface water with fertilizers, pesticides, metals and other sediments.
- It is an excellent source of water for landscape irrigation with no chemicals and dissolved salts and free from all minerals.
Watershed management - Definition, Necessity and methods
Definition
Watershed management is a term used to describe the process of implementing land use practices and water management practices to protect and improve the quality of the water and other natural resources within a watershed by managing the use of those land and water resources in a comprehensive manner.
Necessity
Runoff from rainwater or snowmelt can contribute significant amounts of pollution into the lake or river. Watershed management helps to control pollution of the water and other natural resources in the watershed by identifying the different kinds of pollution present in the watershed and how those pollutants are transported, and recommending ways to reduce or eliminate those pollution sources.
All activities that occur within a watershed will somehow affect that watershed’s natural resources and water quality. New land development, runoff from already-developed areas, agricultural activities, and household activities such as gardening/lawn care, septic system use/maintenance, water diversion and car maintenance all can affect the quality of the resources within a watershed. Watershed management planning comprehensively identifies those activities that affect the health of the watershed and makes recommendations to properly address them so that adverse impacts from pollution are reduced.
Watershed management is also important because the planning process results in a partnership among all affected parties in the watershed. That partnership is essential to the successful management of the land and water resources in the watershed since all partners have a stake in the health of the watershed. It is also an efficient way to prioritize the implementation of watershed management plans in times when resources may be limited.
Because watershed boundaries do not coincide with political boundaries, the actions of adjacent municipalities upstream can have as much of an impact on the downstream municipality’s land and water resources as those actions carried out locally. Impacts from upstream sources can sometimes undermine the efforts of downstream municipalities to control pollution. Comprehensive planning for the resources within the entire watershed, with participation and commitment from all municipalities in the watershed, is critical to protecting the health of the watershed’s resources.
Methods
- To improve the groundwater level, several civil structures are constructed in the watershed area, pits and trenches.
- The pits or trenches are dogged at equal intervals on the skipping surface to cut the surface – flow and to allow it to percolate through these trenches to enrich the ground level.
- Stone embankment or earthen dams.
- They are constructed to check the surface – runoff in the catchment areas, to enrich the groundwater.
- The farm pond.
- They are constructed near the agriculture field in the catchment area to provide enough surface water to the filed and also to enrich the groundwater.
- Dykes or underground barriers.
- These structures are constructed in the small surface streams e.g. The nallahs, to prevent the free groundwater flow and allow the water-table to come up, to help to improve the irrigation through the dug – wells.
A ‘green’ building is a building that, in its design, construction or operation, reduces or eliminates negative impacts, and can create positive impacts, on our climate and natural environment. Green buildings preserve precious natural resources and improve our quality of life.
There are a number of features which can make a building ‘green’. These include:
- Efficient use of energy, water and other resources
- Use of renewable energy, such as solar energy
- Pollution and waste reduction measures, and the enabling of re-use and recycling
- Good indoor environmental air quality
- Use of materials that are non-toxic, ethical and sustainable
- Consideration of the environment in design, construction and operation
- Consideration of the quality of life of occupants in design, construction and operation
- A design that enables adaptation to a changing environment
However, it is worth noting that not all green buildings are – and need to be - the same. Different countries and regions have a variety of characteristics such as distinctive climatic conditions, unique cultures and traditions, diverse building types and ages, or wide-ranging environmental, economic and social priorities – all of which shape their approach to green building.
Energy efficient buildings (new constructions or renovated existing buildings) can be defined as buildings that are designed to provide a significant reduction of the energy need for heating and cooling, independently of the energy and of the equipments that will be chosen to heat or cool the building.
Your insulation should make your building as airtight as possible. In new buildings, this can be achieved by using high-performance insulation and non-traditional wall systems that offer additional insulation. Replacing doors and windows to avoid air leaks in existing buildings can be a great investment.
Long-term energy and cost savings: an energy efficient building will have the advantage of lower energy, water, and maintenance costs. Lower emissions and overall environmental impact: energy efficient buildings have lower greenhouse gas emissions due to their reduced reliance on fossil fuels.
The riverfront is defined by adding cultural and recreational activities along the entire stretch. Development of the riverfront precinct will give it an identity making it a landmark within the city. Various activities have been added along the riverfront making it a vibrant public & cultural place
Principles for Riverfront Development
When planning a riverfront development, let these core principles lead the thinking:
• Feature the riverfront as the front door.
• Showcase the river’s history.
• Activate the riverfront.
• Limit obstacles and connect to the river.
• Engage with the water.
• Connect seamlessly along the riverfront and into neighbourhoods.
• Repair and enhance the environment.
• Employ high-quality architectural materials and sustainable
Engineering practices.
Conservation of heritage structures is an interdisciplinary effort, wherein traditional practices and knowledge on materials, construction and specifications are brought to the realm of current practitioners of conservation engineering, with intent to merge them into the modern tools and construction practices.
Conservation of heritage buildings is very important because it provides a sense of identity and continuity in a fast changing world for future generations. Heritage buildings basically represent the past history and culture of a nation. They constitute together the architectural heritage of an area.
Earthquake-resistant or seismic structures are designed to protect buildings to some or greater extent from earthquakes. While no structure can be entirely immune to damage from earthquakes, the goal of earthquake-resistant construction is to erect structures that fare better during seismic activity than their conventional counterparts. According to building codes, earthquake-resistant structures are intended to withstand the largest earthquake of a certain probability that is likely to occur at their location. This means the loss of life should be minimized by preventing collapse of the buildings for rare earthquakes while the loss of the functionality should be limited for more frequent ones.
Earthquake-resistant building designs consider the following characteristics that influence their structural integrity: stiffness and strength, regularity, redundancy, foundations, and load paths.To withstand collapse, buildings need to redistribute the forces that travel through them during a seismic event. Shear walls, cross braces, diaphragms, and moment-resisting frames are central to reinforcing a building. Made of panels, these walls help a building keep its shape during movement.
The 5 key features of any earthquake-proof building across the globe are:
- Stiffness
- Multiple safety strategies
- Foundations
- Cross braces
- Materials
