Posts by Kanwarjot Singh

Steep slopes are prone to intermittent high velocity flows during rainstorm and this causes erosion at slope surface which prevents the growth of vegetation.

Erosion control mat is installed to control soil erosion and provide soil stability until vegetation can be established. The principal function of erosion control mat is to prevent pre-vegetated soil loss by stabilizing and protecting soils from rainfall and surface erosion. Moreover, it could provide a long-term artificial erosion control system which would increase the shear resistance of vegetation and provide long-term, tenacious reinforcement of the root system.

This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.

In Hong Kong the angle of fill slope is about 30^o– 40^o to the horizontal while the angle of cut slope is about 50^o– 60^oto the horizontal. To protect the slope from surface erosion and water infiltration, it is covered with impermeable hard cover like chunam and shotcrete. Chunam is a mixture of soil, cement and lime and is usually applied in two layers with the thickness of each layer of 25mm. For shotcrete, mesh reinforcement may be provided inside it to enhance tensile strength of cover, thereby reducing the risk of tensile cracking of slope cover.

Weepholes are normally provided in slopes to prevent building up of water pressure in the slope and subsequently this causes cracking and disintegration of slope cover. For gentle slope, hydroseeding may be used and geofabric may be introduced on slope surface to guard against possible surface erosion.

U-channels are provided on the crest and toe of slope to divert and collect the rain falling on slope surface. Catchpits are provided at the intersection or junctions of drains to avoid possible splashing of water.

This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.

The causes of rockfall can be broadly classified into the following two reasons:

(i) Freezing and thawing and the subsequent development of vegetation root pressure in slopes is one of the major causes of rockfall in some countries like Europe. Moreover, rockfall can also be triggered by heavy rainstorms which bring about surface erosion and generate water pressure in rock joints.

(ii) Rockfall can also be induced by poor joint patterns and low strength and water pressure in joints.

This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.

From soil mechanics, it tells us that unsaturated soils get its strength from three main components, namely, friction, cohesion and suction. In building a sand castle in a beach, experience tells us that when sand is too dry or too wet, the castle can hardly be built. However, when the sand is partially saturated, the suction (negative pore water pressure) holds the sand together and provides the strength the build the castle.

In the event of intensive rainfall, the soils cannot get away the water at the rate it is penetrating into the slope and this results in wetting up of the subsurface soils. When the slopes gets too wet (but not yet saturated), it loose much strength in terms of suction (negative pore water pressure) and results in slope failure. This occurs despite the fact that the sliding mass is well above the ground water table.

In Hong Kong about 80% of landslides occur owing to erosion and loss in suction. Only less than 20% of landslides occur as a result of increase of pore water pressure, leading to the decrease in shear strength.

This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.

Following are the IS codes which are used for Building Construction Practices. These IS Codes include standardization in the field of Building Construction Practices and drawing up of codes of practice for building construction and maintenance along with timber structures, masonry, unreinforced masonry, reinforced masonry and other test methods

IS 883:1994 Code of practice for design of structural timber in building

IS 965:1963 Equivalent metric units for scales, dimensions and quantities in general construction work

IS 1414:1989 Code of practice for fixing of wall coverings

IS 1477(Part 1):1971 Code of practice for painting of ferrous metals in buildings:Part 1 Pretreatment

IS 1477(Part 2):1971 Code of practice for painting of ferrous metals in buildings: Part 2 Painting

IS 1597(Part 1):1992 Code of practice for construction of stone masonry: Part 1 Rubble stone masonry
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Following are the IS codes which are used for Functional Requirements In Buildings. These IS Codes include standardization in the field of functional requirements in buildings: from comfort point of view, such as space distribution, orientation, day-lighting, ventilation, acoustics and thermal comforts, from health and safety point of view, from the point of view of accessibility for persons with disability and from the point of view of energy requirements.

IS 1950:1962 Code of practice for sound insulation of non-industrial buildings

IS 2440:1975 Guide for day lighting of buildings

IS 2526:1963 Code of practice for acoustical design of auditoriums and conference halls

IS 3103:1975 Code of practice for industrial ventilation

IS 3362:1977 Code of practice for natural ventilation of residential buildings
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Following are the IS codes which are used for standardization of Doors, Windows And Shutters. These IS Codes include standardization in the field of doors, windows, ventilators, gates and shutters made of any material.

IS 1003(Part 1):2003 Timber panelled and glazed shutters: Part 1 Door Shutters – Specification

IS 1003(Part 2):1994 Specification for timber panelled and glazed shutters: Part 2 Window and ventilator shutters

IS 1038:1983 Specification for steel doors, windows and ventilators

IS 1081:1960 Code of practice for fixing and glazing of metal (steel and aluminium) doors, windows and ventilators

IS 1361:1978 Specification for steel windows for industrial buildings

IS 1948:1961 Specification for aluminiium doors, windows and ventilators

IS 1949:1961 Specification for aluminium windows for industrial buildings
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By
Kevin J. LaMalva
Simpson Gumpertz & Heger, Inc.

Abstract
This research involves a failure analysis of the internal structural collapse that occurred in World Trade Center 5 due to fire exposure alone on September 11, 2001. It is hypothesized that the steel column-tree assembly failed during the heating phase of the fire. Abaqus/Standard was used to predict the structural performance of the assembly when exposed to the fire. Results from a finite element, thermal-stress model confirms this hypothesis, for it is concluded that the catastrophic, progressive structural collapse occurred approximately 2 hours into the fire exposure.

Keywords:
Collapse, Coupled Analysis, Failure, Fire, Heat Transfer, Interface Friction, Structural, Thermal-Stress, World Trade Center (WTC)

1. Background
World Trade Center 5 (WTC 5) was a nine-story building in the World Trade Center complex in New York City, NY (Figure 1). On September 11, 2001, flaming debris from the World Trade Center Tower collapses ignited fires in WTC 5. These fires burned unchecked, ultimately causing a localized interior collapse from the 8th floor to the 4th floor in the eastern section of the building (Figure 2). Debris impact was not a direct factor in this failure; the collapse was caused by fire alone.
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Following are the IS codes which are used for standardization of Timber and Timber Stores. These IS Codes include standard names of indian timbers along with classification of commercial timbers and their zonal distribution; characteristics of imported and plantation timbers; timber, sizing defects of; timber for air craft; timber for marine purposes; seasoning and treatment of timber; logs for plywood; glossary of technical terms used in timber technology; standard dimensions for wood poles of indian species for various breaking loads; moisture content and specification of timber for various uses; methods of testing timber; grading of wood; joinery; method of test for the toxicity of wood preservatives to microorganisms and insects, timber in building construction, floors; grading of timber, sizes of graded timber standardization in the field of timber stores including bamboo and cane stores such as wooden handles, wooden containers including plywood tea- chests, cane baskets, bamboo tent poles etc; and any other woodenware items not covered by other IS Codes.

IS 10(Part 1):1990 Specification for plywood tea-chests: Part 1 General

IS 10(Part 2):1996 Specification for plywood tea-chests: Part 2 Plywood

IS 10(Part 3):1974 Specification for plywood tea-chests: Part 3 Battens

IS 10(Part 4):1989 Specification for plywood tea-chests: Part 4 Metal fittings

IS 10(Part 5):1976 Specification for plywood tea-chests; Part 5 Assembly and packing

IS 190:1991 Coniferous sawn timber (Baulks and scantlings) – Specification
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Following are the IS codes which are used for standardization in Structural Engineering And Structural Sections

IS 800:2007 Code of practice for general construction in steel

IS 801:1975 Code of practice for use of cold formed light gauge steel structural members in general building construction

IS 802(Part 1/Sec 1):1995 Code of practice for use of structural steel in overhead transmission line towers, Part 1 Materials, Loads and permissible stresses Section 1 Materials and Loads

IS 802(Part 1/Sec 2):1992 Code of practice for use of structural steel in overhead transmission line towers Part 1 : Material, loads and permissible stress Section 2 Permissible stress
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