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3RD REVIEWPROJECT PHASE - 2DESIGN OF PREFABRICATED MODULAR HOUSING FOR DIFFERENT OCCUPANCIES AT PANCHESHWAR POWER PLANT

BY: FEBA MARY THOMAS (1010910068) HARSHAL RASTOGI (1010910079) JITHESH DHARMADAS (1010910087)

PROJECT GUIDE Dr. M. LAKSHMIPATHY

1Schedule for Phase IIDATEWORK TO BE DONEJANUARY 2013FINALIZED PLAN FOR LIG, MIG, HIG USING MODULAR COORDINATIONFEBRUARY 2013IDENTIFICATION OF COMPONENTS AND DESIGNMARCH 2013DETAILING OF MEMBERS AND CONNECTIONSAPRIL 2013FINALIZATION OF THE REPORT2Progress in Phase IIPreparation of plans for various occupancies.Grid wise distribution of components in plan using modular coordination.Identification of structural elements.Design of structural elements.Detailing of joints and connections.Preparation of the final report.

JOINTS AND CONNECTIONSConnections are among the most essential parts in precast structures. Their performance relates to the structural limit states, as well as to manufacture, erection and maintenance of the structure itself. Proper design of connections is one major key to a successful prefabrication. The main purpose of the structural connections is to transfer forces between the precast concrete elements in order to obtain a structural interaction when the system is loaded.

By the ability to transfer forces, the connections should secure the intended structural behavior of the superstructure and the precast subsystems that are integrated in it. This could for instance be to establish diaphragm action in precast floors and walls, or cantilever action in precast shafts. For this reason the structural connections should be regarded as essential and integrated parts of the structural system and they should be designed accordingly and with the same care as for the precast concrete elements. It is insufficient just to consider the connections as details for site erection. The advantages that normally are obtainable with prefabrication can be lost with an inappropriate design and detailing of the structural connections. FLOOR TO BEAM CONNECTIONSDetails of typical bearing of a floor unit over the precast beam are shown in Fig. 1 the stirrups of the precast beams are protruded and function as shear connectors The reinforcing bars of the in-situ screeding concrete are extended over the beam supports so as to ensure continuity.Fig. 1 Precast slab to beam joint

BEAM TO COLUMN CONNECTIONSThe bracket support for the beam over the column is shown in Fig. 2. A tolerance of 2-3 cm is allowed at the seating of the beam over the bracket.A dowel bar inserted through the holes provided in the bracket and the beam ensures an effective connection between them.The top reinforcing bars of the precast beams are connected to thecolumn joint by welding. Since only a few number of bars are welded, it is assumed that the connection between the beam and the column is a rigid one at the serviceability stage, but behaves as a hinged one at the ultimate stageFig. 2 Precast beam to column joint

FOUNDATIONSThe foundations usually cast as in-situ isolated footings as the local soil conditions warrant.The bottom end of the precast column is connected to the foundation as shown in Fig. 3

Fig. 3 In-situ footing to precast column connection

PRODUCTION AND ERECTIONThe method of production depends on the total number of prefabricated elements that are to be produced. The components may be produced either in a factory on mass scale or in casting yards located near the site and equipped with the necessary plant and machinery.For facilitating erection, lifting hooks are provided in the precast floors and beams. Erection eyes as given in Fig.4 provided in the structural elements help in lifting them during transportation and erection using temporary bracing. For transportation and erection purposes the hook placements adopted are shown in Fig. 5, Fig. 6 and Fig. 7.Fig. 4 Hook details

Fig. 5 Hook placements for slab

Fig. 6 Hook placements for beam

Fig. 7 Hook placements for column