Consideration Selection of Bridge Site

Consideration Selection of Bridge Site

Before a bridge is constructed, a suitable site is selected based on certain factors which have bearing on the economy and stability of the bridge.

1. At bridge site the reach of the stream should be straight.

2. The site should be geologically sound i.e. it should be away from fault zone, and should have unyielding, non erodible foundation for abutments and piers.

3. At the site, the stream should be narrow with well defined and firm banks.

4. At site the river flow should be without whirls and cross currents.

5. At the site there should be suitable high banks above high flood level on each side.

6. The approaches should be economical. They should not be very high or long or liable to flank attacks of the river during floods. They should be free from obstacles such as hills, frequent drainage crossings, built up areas, sacred areas as grave yards, or trouble some land acquisition etc.

7. The site should be at reasonable proximity to a direct alignment of the road to be connected.

8. There should be no sharp curves in the approaches.

9. Absence of costly river training works, where they are unavoidable they should be executed in dry as far as possible.

10. Avoidance of excessive under water construction work.

11. If it is un-avoidable, necessity for the approaches of the bridge to cross the spill zone of a river, they  should (while processing through the spill zone towards the river), face down stream and not up stream. Facing up stream will cause heading up, pocket formation, and danger to the approaches.

Road Making Plants and Machinery

Road Making Plants and Machinery 

In road construction project different machinery is required for different types of jobs. The sequence of

job operations can be as follows:

 1. Clearing the site.

 2. Formation of sub grade—Embankment or cutting.

 3. Spreading of material.

 4. Rolling or compaction.

 5. Surfacing.

 

Machinery used for clearing the site. For site clearance generally following machinery can be used:

  (a) Dozer—bull dozer, angle dozer, tree dozer, etc. 

  (b) Rooter or Ripper.

  (c) Tractor.

  (d) Scraper.

 Formation of sub grade.  For this purpose earth digging equipment is also used as drag line, shovel, etc.

For preparing the sub grade generally following machinery is used:

   (a) Tractor

   (b) Dozer

   (c) Grader

   (d) Shovel

   (e) Drag line

   (f) Clam shell

   (g) Trucks

   (h) Rollers

   ( i )Plough  etc.

Manufacturing and spreading of Material. For this operation generally following equipment is

required:

    (a) Crushers

    (b) Trucks

    (c) Aggregate distributors

4. Surfacing. Surfacing generally consists of the following types:

     (a) Bituminous surfacing

     (b) Concrete surfacing

     For bituminous surfacing following equipment is required:

     (i) Bitumen boiler

     (ii) Bitumen sprayer

     (iii) Aggregate spreader

     (iv) Bitumen mix spreading machine

     (v) Grouting, machine

     (vi) Rollers.

Concrete surfacing needs equipment as follows:

(i)                  Central batching and mixing plant

(ii)                concrete mixers

(iii)               Concrete pavers

(iv)              Concrete sprayer

(v)                 Concrete vibrators etc.

Les Quais by Fabrice Dusapin

Les Quais by Fabrice Dusapin

Architect Fabrice Dusapin came up with a project that complements diversity of urban “quai” of François Mitterrand. “Quai” is a french word for docks. Project, located on the banks of Loire river in the french city of Nantes, has very different building heights and volumetric comparing to an existing renewed house and a new residential building. Located on a large parcel, the project offers a space with an alley and access to the Loire river. This project is composed from four parts: maison de ville, ateliers, centre and building itself that fits around a square that represents heart of the area. Residents of apartments have a fabulous view at the river and take advantage of natural lighting. The yard catches eye at first sight; various shapes like some very different buildings glued together. The conglutination reflects on functionality of these buildings - the yard is poly-functional. It houses residential parts as well as shops, parking slots, small square or halls for local activities.

Les Quais / Fabrice Dusapin

Architect:  :   Fabrice Dusapin, architectes, urbanistes

Location   :   Ile de Nantes, Nantes, France

Client:       : PROMOGIM

Site area  :  6,205 sqm

Built area  : 11,800 sqm

Project year: 2010

Floor plan

Site plan

Industrial Building Systems

Industrial Building Systems are those structures used by an industry; this can be of any type ranging from salt and sand to those manufacturing of heavy equipment.   Generally at least a part and in most cases the entire area is of one storey height.  These buildings offer column free support and there lengths can vary largely, also these types of buildings provide thousands of usable square feet for manufacturing needs thereby offering the most cost effective solution in the market today.

Also these buildings are fully customizable with a variety of ceiling lights, windows, insulation and doors.   The speed of erection, high strength to weight ratio and ease of extension make steel the most popular industrial building material. Types of Industrial Buildings These industrial buildings can be classified in different ways, given below are two major ways of classification:

• Normal type building systems
• Special type building systems.

 

Also normal usage identifies, normal type building systems as the shed type building systems which is a rather rough construction used basically for storage purposes.  Also popular are the open frame structures that mainly consist of a structure supported by a skeleton made of steel or reinforced concrete rather than by load-bearing walls.  They often have diagonal bracing or shear walls and diaphragms for lateral stability; the strength of steel only makes it possible to have buildings with longer spans

A wide variety of building types exists, ranging from major structures, such as power stations and process plants, to small manufacturing units for high quality goods.

The most common type is the simple rectangular structure, typically single-storey, which provides a weatherproof and environmentally comfortable space for carrying out manufacturing or for storage. First cost is always an overriding consideration, but within a reasonable budget a building of good appearance with moderate maintenance requirements can be achieved. While ease of extension and flexibility are desirable, first cost usually limits the provisions which can be usefully included in the design for these potential requirements. Although suitable provisions can achieve savings in the cost of specific future modifications, for example by avoiding, the use of special gable frames, changes in manufacturing processes or building use may vary the modifications required.

Master builder

Dampness in Buildings Causes

Dampness is the presence of hygroscopic moisture in the buildings. Ground water contains soluble salts, the most significant of which are chlorides, nitrates and sulphates. When dampness occurs, these pass with the water up the wall and are left behind when the water evaporates. Over many years of active dampness, large quantities of these salts accumulate within the masonry and decorative surface,

 most becoming concentrated in a general 'salt band'. Both chlorides and nitrates are usually hygroscopic, (i.e. they can absorb moisture from the surrounding environment) and, in general, the greater the amount of salts the greater the absorption of moisture - especially under humid conditions. 

 It leads to unhygienic conditions affecting badly the health and comfort of the inhabitants and deteriorating the buildings. Protection against dampness should form an essential feature for any type of construction.
Sources of Dampness
The sources which create dampness in buildings are 

a.    Geological and climatic conditions

• Rain penetration
• Ground moisture rise
• Condensation in buildings due to moisture in the atmosphere
• Drainage of the site
• Orientation of the buildings

b. Structural causes

• Water used during construction
• Defective construction

Effects of Dampness: 

Dampness tends to cause secondary damage to a building. The unwanted moisture enables the growth of various fungi in wood, causing rot. Plaster and paint deteriorate and wallpaper loosens. Stains, from the water, salts and from mould, mar surfaces. Floor coverings loose their bond with floor bases. 

Externally, mortar may crumble and salt stains may appear on the walls. Steel and iron fasteners rust. Electrical installations get damaged. It may also cause respiratory illness to the occupants. In extreme cases, mortar or plaster may fall away from the affected wall. 

Dampness in buildings can generally be divided into three main catagories, each caused by a different phenominum. The categories are rising damp, penetrating damp and condensation. 
Dampness is a major source of disrepair in a building and can be caused by several factors such as 

• Leaking pipes or overflows
• Rain seeping through the roof, spilling from a blocked gutter, seeping in around windows
• Rising damp due to a defective damp proof course or missing damp proof course
• Condensation where moisture in the air condenses onto cold surfaces