CIVIL YAAR

 →Definitions of Earthquake: -  Earthquake is defined as the shaking of earth’s surface due to any reason which, result in  release of large amount of energy. For example-: The energy released in during 2001 Bhuj Earthquake (Gujrat, india) was  about 200 times that of energy released by Atom bomb dropped on Hiroshima  (Japan) In the year of 1945.  Or * The ground vibrations, both feeble and strong, produced on the surface of earth due to any  reason what so ever are described as earthquake. * Define Earthquake Engineering/Seismology-: The branch of science which deals with the study of earthquakes. It includes causes and types of earthquake, Study of origin, Propagation, Recording and  analyzing seismic waves that occur inside the earth along with the source that produce them  is known as Earthquake Engineering or Seismology. * Important Terminology related with Earthquake Engineering  Seismology-: 1. Hypocenter or focus or seismic cente...

भूकंपीय तरंगें पृथ्वी से गुजरने वाली सभी दिशाओं में संचारित तरंगें रिहाई के कारण भूकंप के दौरान सतह  भूकंपीय तरंगें दो प्रकार की होती हैं: 1) बॉडी वेव 2) सरफेस वेव्स 1) शारीरिक लहरें भूकंपीय तरंगें जो सभी में पृथ्वी की परतों से होकर गुजरती हैं दिशाएं और किसी भी गहराई तक सीमित नहीं हैं जिन्हें बॉडी कहा जाता है लहर की। ये दो प्रकार के होते हैं: a) प्राथमिक तरंगें या P- तरंगें बी) माध्यमिक लहरें या एस-लहरें a) PRIMARY WAVES या P-WAVES शरीर की तरंगें जिसमें भौतिक कण की दिशा में कंपन करते हैं एक धक्का और पुल प्रभाव के साथ लहर के प्रसार के रूप में कहा जाता है प्राथमिक लहरें या पी-लहरें। `इन्हें लोंगिट्यूडिनल या कंप्रीहेंसिव वेव्स के नाम से भी जाना जाता है। पी-लहरों की विशेषताएं • ये तरंगे सबसे तेज़ होती हैं और इसलिए ये सबसे पहले होती हैं रिकॉर्डिंग स्टेशन पर दर्ज की गई। • ये तरंगें ठोस के माध्यम से गुजरने में सक्षम हैं साथ ही तरल पदार्थ। • ये लहरें प्रारंभिक झटकों के लिए जिम्मेदार हैं पृथ्वी की सतह। • ये तरंगें ध्वनि तरंगों की तरह होती हैं। • इन तरंगों के कारण सामग्री में वॉल्यूमेट्रिक प...

        Seismic Zoning  It can be defined as dividing a country or region into smaller zones on the basis of their seismicity or earthquake activity. It depends on : a) The detail study of the earthquake that have occurred in past, their characteristics like magnitude, intensity and damage. b) The tectonic feature of the place which could cause an earthquake in future. Tectonic feature of India India lies at the north- western end of the Indo- Australian plate. On this plate, India, Australia, a major part of the Indian Ocean and other smaller countries are located. This plate is colliding against other neighbouring plates. 3 major tectonic plates of India are a) Northern Himalayas b) Plains of the Ganges and other rivers c) The Peninsular Region Northern Himalayas The Himalayan Ranges comprises of highly seismic zone which is very unstable. All along the foothills of Himalayas, stretching from Kashmir to Assam is a long thrust fault known as Great Boundary Faul...

THEORIES OF TECHTONIC EARTHQUAKE:- Various causes of tectonic earthquake occurring on earth surface have been explained by the scientists and geologists on the basis of following theories: 1. ELASTIC REBOUND THEORY 2. THEORY OF PLATE TECTONICS ELASTIC REBOUND THEORY • According to this theory, earthquakes are caused by gradual accumulation and release of stress and strain in layers of rocks forming the earth’s crust. • In this we consider an individual rock unit in which continuously increasing shear strain is acting. • Firstly the condition is of no strain. • When the stress exceeds the elastic limit, a crack or fracture is developed. • Due to friction between rock masses there is no movement, but the blocks are distorted and blocks are said to be strained. • In order to reduce the strain to a minimum, the two distorted and fractured blocks tends to slip off from one another to a position of no strain. This is known as ELASTIC REBOUND. THEORY OF TECTONIC PLATES ➢ According to this the...