Reinforcement Requirement of Two Way Concrete Slab

In case of flexural reinforcement extending in one direction only, reinforcement for shrinkage and temperature stresses shall be provided perpendicular to flexural reinforcement in structural slabs. But, in case of, two-way slab where reinforcement requirements are determined by flexure in critical section, the minimum reinforcement is set to the limit of those of temperature and shrinkage.

Spacing of reinforcement at critical sections shall not exceed two times the slab thickness, except for portions of slab area that may be of cellular or ribbed construction. In the slab over cellular spaces, reinforcement shall be provided as required by shrinkage and temperature, stated above.


Positive moment reinforcement perpendicular to a discontinuous edge shall extend to the edge of slab and have embedment, straight or hooked, at least 150 mm in spandrel beams, columns or walls.


Negative moment reinforcement perpendicular to a discontinuous edge shall be bent, hooked, or otherwise anchored, in spandrel beams, or wall, and shall be developed at face of support according to provisions for standard development and splices reinforcement.


Corner Reinforcement

1.Special reinforcement shall be provided at exterior corners in both bottom and top of the slab, for a distance in each direction from the corner equal to one-fifth the larger span of the corner panel.

2.Corner reinforcement at the top of the slab shall be parallel to a line bisecting the angle at the relevant corner.

3.The corner reinforcement at the bottom of the slab shall be perpendicular to a line bisecting the angle at the relevant corner.

4.The top and bottom corner reinforcement shall be of size and spacing equivalent to that required for the maximum positive moment in the panel

Guidance for Removal of Forms and Shores

No construction loads shall be supported on, nor any shoring removed from, any part of the structure under construction except when that portion of the structure in combination with remaining forming and shoring system has sufficient strength to support safely its weight and loads placed thereon.

Sufficient strength shall be demonstrated by structural analysis considering proposed loads, strength of forming and shoring system, and concrete strength data. Structural analysis and concrete strength test data shall be furnished to the engineer when so required.

No construction loads exceeding the combinations of superimposed dead load plus specified live load shall be supported on any unshored portion of the structure under construction, unless analysis indicates adequate strength to support such additional loads.

Forms shall be removed in such a manner as not to impair safety and serviceability of the structure. All concrete to be exposed by form removal shall have sufficient strength not to be damaged thereby.

Forms supporting prestressed concrete members shall not be removed until sufficient prestrtessing has been applied to enable prestressed members to carry their dead load and anticipated construction loads.

Destruction of Bhuj Earthquake, Gujarat

The Mw7.6 Bhuj earthquake that shook the Indian Province of Gujarat on the morning of January 26, 2001 (Republic Day) is one of the two most deadly earthquakes to strike India in its recorded history. 

One month after the earthquake official Government of India figures place the death toll at 19,727 and the number of injured at 166,000.


Indications are that 600,000 people were left homeless, with 348,000 houses destroyed and an additional 844,000 damaged. The Indian State Department estimates that the earthquake affected, directly or indirectly, 15.9 million people out of a total population of 37.8 million.

More than 20,000 cattle are reported killed. Government estimates place direct economic losses at $1.3 billion. Other estimates indicate losses may be as high as $5 billion.

Slope Stability & Protection against Excavation

The possibility of overturning and sliding of the surrounding building shall be considered during excavation. The minimum factor safety against overturning of the structure as a whole shall be 1.5. Stability against overturning shall be provided by the dead load of the building, the allowable uplift capacity of piling, anchors, weight of the soil directly overlying footing provided that such soil can't be excavated without recourse to major modification of the building, or by any combination of these factors.

The minimum factor of safety against sliding of the structure under lateral load shall be 1.5. Resistance to lateral loads shall be provided by friction between the foundation and the underlying soil, passive earth pressure, batter piles or by plumb piles, subject to the following:

1. The resistance to lateral loads due to passive earth pressure shall not be taken into consideration where the abutting soil could be removed inadvertently by excavation.
2. In case of pile supported structures, frictional resistance between the foundation and the underlying soil shall be discounted.
3. The available resistance to friction between the foundation and the underlying soil shall be predicted on an assumed friction factor of 0.5. A greater value of the co-efficient of friction may be used subject to verification by analysis and test.

The faces of cut and fill slopes shall be prepared and maintained to control erosion. The control may consist of effective planting. The protection for slopes shall be installed as soon as practicable. Where cut slopes are not subjected to erosion due to erosion resistant character of the materials, such protection may be omitted.

Where necessary, check dams, cribbing, riprap or other devices or methods shall be employed to control erosion.

Splice in Steel Piles

Steel piles are usually rotted H shapes or pipe piles. Wide-flange beams or I beams may also be used; However, the H-shape is especially proportioned to withstand the hard driving stress which the pile may be subjected.

Splices in steel plate are made in the same manner as in steel columns, i.e., by welding (most commonly) or by bolting. Except for small projects involving only a few piles, currently most splices are made with prefabricated (and patented) splices connectors. For H piles, web plates are prefabricated in the form of two channels back-to-back, of adequate length which fit snugly against the web and inside flange. 

The splice is then welded to the web across the ends and the flanges are butt welded to complete the splice pipe pile splicers consists in a ledge ring with an inner dia slightly larger than the pipe outer dia. The two sections of pipe to joined rest against the inside ledge and an end weld is made around the pipe at both ends of the splice. Generally these splices will develop the strength of the pile in compression, tension, bending, and shear to satisfy most building code requirements.

When a pile must be spliced to develop adequate embedment length, all the necessary equipment should be standing by so that when the hammer is shut off the splice can be quickly made. If this is not done – and sometimes if it is done-the soil tends to set or "freeze" about the pile, and resumption of driving is difficult and sometimes requires changing hammers. These large driving stresses may cause considerable damage to the upper part of the pile. This is a phenomenon which is independent of pile materials.

Formation of Andes (Tectonic Cause)

The Andes mountain range is the highest mountain range outside Asia. The highest peak, Aconcagua, rises to 6,962 m (22,840 ft) above sea level. The summit of Mount Chimborazo in the Ecuadorean Andes is the point on the Earth's surface most distant from its center, because of the equatorial bulge.

But the Andes are the world's longest exposed mountain range. They lie as a continuous chain of highland along the western coast of South America. The range is over 7,000 km (4,300 mi) long, 200 km (120 mi) to 700 km (430 mi) wide (widest between 18° to 20°S latitude), and of an average height of about 4,000 m (13,000 ft).

 The Andes are the result of plate tectonics processes, caused by the subduction of oceanic crust beneath the South American plate. The main cause of the rise of the Andes is the compression of western rim of the South American Plate due to the subduction of Nazca Plate and the Antarctic Plate.

  The formation of the modern Andes began in the Jurassic Period. It was during the Cretaceous Period that the Andes began to take their present form, by the uplifting, faulting and folding of sedimentary and metamorphic rocks of the ancient cratons to the east. Tectonic forces along the subduction zone along the entire west coast of South America where the Nazca Plate and a part of the Antarctic Plate are sliding beneath the South American Plate continue to produce an ongoing orogenic event resulting in minor to major earthquakes and volcanic eruptions to this day. In the extreme south a major transform fault separates Tierra del Fuego from the small Scotia Plate. Across the 1,000 km (620 mi) wide Drake Passage lie the mountains of the Antarctic Peninsula south of the Scotia Plate which appear to be a continuation of the Andes chain.

Corrosion Problem of Steel Piles

According to National Bureau of Standards ( NBS), pile driven in disturbed, or fill, soils will tend to undergo relatively more corrosion. This study is applicable for both sheet-pile and bearing pile. Undistured soils were found to be Oxygen-deficient from a few feet below the ground surface while the disturbed soil contain a high concentration.

The soil considered as corrosion  susceptible, according to NBS, is:

P^H   = 2.3 _- 8.6  
_{b)  Electrical resistivity of 300  to 50200 ohm. cm.}

Soil exposed to sea water or effluents with a PH much above 9.5 or below 4.0 will required painting or encasement in concrete to resist corrosion. This is also true for zones where the piles are subjected to water fluctuations foe several feet. A splice, increasing section slightly in the corrosive zone, may suitable alternative to the treatment stated above.


Some of the newer grades of high-strength and copper-alloy steels claim substantial corrosion resistance. The A690 high-strength low-alloy steel has approximately two to three times more corrosion resistance to sea water them ordinary carbon steel of A36 grade.

Formation of Mount Everest disappearing Tethys Sea

About 50 million years ago, the collision of the Indian subcontinent and Asia, gave a great height to Mount Everest. Although the northward drift of India slowed dramatically with initial collision, the two continents have continued to converge as India slides under Asia.


Prior to the initial collision between India and Asia, the vast Tethys Sea existed between the two. The sea disappeared, a victim of plate tectonics, but its presence before 50 million years ago is recorded by scraps of oceanic crust preserved in the southern Tibetan plateau. It is not surprising that scientists consider the Himalayan range to be one of the planet’s best natural laboratories for studying the mountain building process and associated seismic activity. Dr. Bilham, a geophysicist on the EVEREST team, is conducting research to better understand the processes that drive seismic activity in Nepal and to help assess the danger of destructive earthquakes in Nepal and northern India. In this century, four earthquakes of Richter Magnitude 8 or greater have occurred in the Himalayas. Scientists expect another of similar magnitude to occur yet this century, putting millions of lives at risk.


At 29,028 feet, Mount Everest is five miles up — about the cruising altitude of a jet airliner. Data collected by Dr. Bilham indicates the world’s highest mountain is creeping skyward 3 to 5 millimeters with every passing year. Every time a team reaches the summit, the climbers are essentially setting a new altitude record.

Loads on Helicopter Landing Area

In addition to the all loads (Rain loads, loads due to flood and surge, temperature effects, snow load, soil and hydrostatic pressure, loads due to explosions, and vertical forces on air raid shelter) that may occur in this(Helicopter Landing Area) area including dead loads, the minimum live load on helicopter Landing or touchdown Area shall be one of the loads L1, L2, L3 as given below producing the most unfavorable effect:

1. L1 = W1

2. L2 =KW2

3. L3 = w

World Highest Helipad in Burj Al Arab 

Where, W1 = Actual weight of the helicopter in KN,

W2= Fully loaded weight of the helicopter in KN,

w = A distributed load of 5.0 KN/m2,

K=0.75 for helicopters equipped with hydraulic type shock absorbers and

= 1.5 for helicopters with rigid or skid type land

Helicopter Landed on World Highest Helipad in Burj Al Arab 

The live load, L1 shall be applied over the actual of contact of landing. The load, L2 shall be a single concentrated load including impact applied over a 300 mm X 300 mm area. The loads, L1 and L2 may be applied anywhere within the landing area to produce the most unfavorable effects of loading.