BURJ DUBAI- Worlds Tallest Building

                           As with all super-tall projects, difficult structural engineering problems needed to be addressed and resolved. This paper presents the approach to the structural system for the Burj Dubai Tower. This paper first presents the architectural knowledge and the comparison of the Burj Dubai tower with other tall buildings of the world. It also describes the geotechnical procedures and structural detailing of the building besides the wind engineering applied to the tower.

Burj Dubai (Arabic: برج دبي‎ "Dubai Tower"), a supertall skyscraper under construction in Dubai, United Arab Emirates, is the tallest man-made structure ever built, at 818 m (2,684 ft). Construction began on 21 September 2004, and the tower is expected to be completed and ready for occupancy by the end of 2009

The building is part of the 2 km2 (0.8 sq mi) flagship development called "Downtown Burj Dubai" at the "First Interchange" along Sheikh Zayed Road, near Dubai's main business district. The tower's architect is Adrian Smith, who worked with Skidmore, Owings and Merrill (SOM) until 2006.The Chicago-based architecture and engineering firm SOM is in charge of the project.The primary builders are Samsung Engineering & Construction and Besix along with Arabtec. Turner Construction Company was chosen as the construction manager.
The total budget for the Burj Dubai project is about US$4.1 billion, and for the entire new "Downtown Dubai", US$20 billion.

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SKYLIGHTS

                           Adding a skylight is one of the quickest and easiest ways to make any room of your home lighter and brighter, adding an open and airy feeling. There are two basic types of skylights for residential use – flat glass and domed acrylic – and each have some advantages.
Domed acrylic skylights are less expensive than glass, and their convex shape tends to let the rain wash accumulated dust and dirt off a little easier. The acrylic dome is mounted in an aluminum frame, which is in turn mounted on a 2x6 box called a "curb." Once the hole is cut in the roof to the manufacturer’s specifications, the curb is constructed on-site to raise the skylight above the level of the roof sheathing. Site- built or factory-supplied flashings are used to seal the roofing around the curb.

Domed skylights are available in clear, smoked, bronze or other tints. Most are double- or triple-glazed in order to achieve the level of energy efficiency required by the building codes. Several sizes are available, with the most common being 2x2, 2x4 and 4x4 feet.
Flat glass skylights come mounted in a wood or integrated rubber and metal framework, and require no additional curb construction. After the hole is cut, the skylight frame is simply attached to the roof sheathing with L- brackets, then the installation is completed using the factory- supplied flashing kit. Easy installation, superior insulating qualities, less tendency to scratch and a cleaner finished appearance all add to the popularity and somewhat higher cost of glass skylights.

Glass skylights also have a greater number of optional accessories. These include tempered, laminated or wire glass; shades and blinds for light control; glass tints for heat retention or to block sunlight; and the ability to open fully or partially for ventilation. At least one company, Velux – a leading manufacturer of quality glass skylights that are available at most local home centers and lumber yards – even offers an electric motor coupled to a rain sensor that automatically shuts the skylight if it detects rain.

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Introducing Bio-engineering to the Road Network

                           Bio-engineering is the use of vegetation, either alone or in conjunction with civil engineering structures, to reduce instability and erosion on slopes. It should be a fundamental part of the design and construction of all roads in rural (and urban) hill areas, mainly because it provides one of the best ways to armour slopes against erosion. Because of the steep and dynamic slopes found in the Himalayas, most hill roads are engineered near to the margin of safety. Bio-engineering is an effective way of enhancing civil engineering structures to increase stability as far as possible. It is relatively low in cost uses local materials and skill, and provides livelihoods benefits through. economically useful products..

A study has shown that many roadside slopes in Himachal Pradesh (HP) suffer from a range of
instability and erosion problems, many of which are conducive to the use of low cost remedies such as bio-engineering. The Public Works Department (PWD) is examining alternatives to standardise civil engineering approaches and in particular is looking at the possibilities offered by bio-engineering, through the experience gathered in other parts of the Himalayas over the last few decades Between 1987 and 1990, the PWD’s Horticulture Wing was involved in soil conservation work to resolve shallow failures on road cut slopes. Though this programme has diminished with time, it still demonstrates the inherent capabilities that can be harnessed to good effect.

This paper describes the main types of slope instability found in Himachal Pradesh, their causes (natural and man made), treatment options to safeguard the road network and reduce long term maintenance costs; approaches to bio-engineering that are appropriate to the bio-physical and socioeconomic conditions found in the state; institutional mechanisms for these to be successful; capacity enhancement means and tools; and examples of success and failures from other parts of the world. It also documents early experience in the introduction of this type of approach through specific pilots of critical road sections that have been considered under the World Bank funded Himachal State Roads Project.

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GEOTEXTILES IN ROAD CONSTRUCTION, MAINTENANCE AND EROSION CONTROL

                           Textiles were first applied to roadways in the days of the Pharaohs Even they struggled with unstable soils which rutted or washed away They found that natural fibers, fabrics or vegetation improved road quality when mixed with soils, particularly unstable soils Only recently, however, have textiles been used and evaluated for modern road construction This fact sheet clarifies the confusion over terms and definitions of geotextiles, and discusses their common roadway and erosion control applications. In the 1920’s the state of South Carolina used a cotton textile to reinforce the underlying materials on a road with poor quality soils Evaluation several years later found the textile in good workable condition They continued their work in the area of reinforcement
and subsequently concluded that combining cotton and asphalt materials during construction
reduced cracking, raveling, and failure or- the pavement and the base course.

When synthetic fibers became more available in the 1960’s, textiles were considered more
seriously for roadway construction and maintenance As these new synthetic fabrics evolved, there was confusion over terms and definitions Textiles and membranes now have reasonably well accepted definitions in the construction industry, due mostly to the work of Dr Jean Pierre
fabric Non-woven geotextile fabric is more likely to stretch than woven geotextile It has the
ability to let water flow along the plane of the geotextile. The woven geotextile, which looks like burlap, is a sheet made of two sets of parallel strands systematically interlaced to form a
thin, flat fabric The strands may be slit film which are flat, or monofilaments which are round
(Figure 3) The way these two sets of yarns are interlaced determines the weave pattern which in turn determines the best application for that woven fabric.

Weave patterns come in a virtually unlimited variety which do affect some properties of the fabric However, a buyer will specify properties of the fabric such as porosity, strength and elongation, not weave pattern In general a woven geotextile is less likely to stretch, and does not let water flow as freely as non-woven geotextiles.

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BLOCK SHEAR FAILURE IN TENSION MEMBERS

                           Block shear is a limit state that should be accounted for during the design of steel tension members. This failure mechanism combines a tensile failure on one plane and a shear failure on a perpendicular plane. It is important for a design equation not only to predict the capacity reliably, but also to predict accurately the failure mode. In this study, we begin with an overview of tension members, their behaviour and design strength which is affected by yielding, fracture or block shear. Different codal provisions in ISO 800: 2007 for tension members have been dealt, with a special focus on block shear and its failure mechanism. Latest specifications on block shear in AISC 2005 and Eurocode 3 have also been explained so as to provide a broader view of the standards being adopted worldwide to check failure of structures by block shear. Recent developments in block shear research have also been discussed, both finite element analysis and experimental programs.

Block shear failure is not just limited to bolted connections and keeping this in mind, research works conducted on block shear in bolted as well as welded steel sections have been presented herein. Finally, a numerical on block shear has been solved using the provisions in IS 800, AISC 2005 and Eurocode 3. The results obtained shows the given section to be safe from block shear failure; with the Eurocode provisions predicting the lowest design strength (though more than the applied reaction), AISC value being the highest and IS 800 values somewhere in the middle range. Based on these findings and studies, a conclusion has been arrived at and presented at the end of the report

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Fiber micro-buckling

                          Experimental results on fiber micro-buckling of continuous glass-fiber reinforced hollow-cored recycled plastic extrusions under creep tests are introduced in the paper. The full size specimens with dimensions in 2:5 3:5 42 in:3 were submerged in warm water
at a temperature of 125 F when they were under a four-point bending creep test. The results show that the micro-buckling of the embedded glass-fiber roving occurs along 90% the length of the specimen on the upper inner surface (compressive side) and mainly during the time between 5 and 100 h from the initial loading moment. The micro-buckling causes the steady-state apparent flexural modulus of the composite drop faster, and it also causes the plastic matrix local crackling which subsequently leads to the structural failure of the composite. The stress level has little effect on the steady-state creep rate. The results also show some evidence that the plastic matrix becomes more brittle when it is submerged in warm water for certain long time. From the results, it is indicated that the pattern or distribution of the micro-buckling is significantly different from that of short-term four-point bending test for the same composite materials, for which the fiber micro-buckling occurs locally only on the middle section of the specimen

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