Manual on Hazard Resistant Construction in India: For Reducing Vulnerability in Buildings01 Jul 2008
This manual focuses on construction of hazard resistant masonry buildings as well as restoration and retrofitting of the existing masonry buildings .It has been observed that even RCC construction is also often done in a non-engineered manner.
Natural phenomena like earthquake and cyclones become disasters because of lack of awareness on how to construct affordable disaster resistant houses by using viable technologies. It has been observed that this ignorance results in the violation of the basic rules of good construction and hazard resistant technology leading to deaths, injury and unwarranted hardship to the people along with huge losses in terms of houses and infrastructure. In addition to the direct losses caused by the disaster it has been observed that the people suffer self-inflicted losses out of ignorance and under the influence of the unscientific myths that prevail after the disasters. For example the Latur Earthquake made people think that there was no future in their houses that were built out of stone, wood and mud, or those with foundation built on soil instead of on rock, or those that were made with loadbearing system. This led them to get their houses dismantled and sell the salvaged material at a throw away price. As a result tens of thousands of families lost perfectly good undamaged houses. This manual focuses on construction of hazard resistant masonry buildings as well as restoration and retrofitting of the existing masonry buildings .It has been observed that even RCC construction is also often done in a non-engineered manner. Hence, some basic but critical information is provided on RCC construction also. Since the manual is meant to guide contractors, masons and house-owners, a maximum possible use of visuals including photographs of actual construction has been made with text included where required. The manual is based on various codes and guidelines of Bureau of Indian Standards and is linked to the Vulnerability Atlas made by Ministry of Housing and Urban Poverty Alleviation, GoI. In addition the practical experience of the authors for the past one-and-a-half decades in retrofitting of hundreds of vernacular structures as well as in construction of new houses applying hazard resistant technology with local materials in widely differing regions of the country has provided a sound footing in the preparation of this manual. It should be noted that the list of rules and measures given in this manual is not exhaustive. But the most critical rules are covered. The measures given here cover the most common types of buildings in the country. The understanding of the underlying principles should help the reader to evolve measures for other situations. Since there are great variations in the construction practice of masonry structures in different parts of the country, some of the important regional variations are also included in the manual to enable the house owner and the masons to relate to various measures in reference to the locally used construction methods.
The information provided in this manual is essentially for the higher risk areas including Seismic Zones III, IV and V, Wind Speed Zones III and IV with wind speeds ranging from 47 to 55m and the areas affected by the floods. But the people in the other zones also could refer to it for guidance. The manual has evolved to be comprehensive on account of the reasons indicated above. It is expected that masons will be initiated in the use of this manual as a part of a training program so that they get the maximum benefit out of the Manual. Once the training is completed this Manual can be used as a reference book to be used as often as required. This manual is equally useful to the site supervisors, engineers, and by those wanting to get their house built by a mason. We earnestly hope that they too would make use of this manual. Finally, it is intended that this manual will help in reducing the undue losses and hardships to the people when struck by an earthquake, cyclone or a flood, and that it becomes an important tool in making India less vulnerable to disasters.