SOIL COMPACTION EQUIPMENT AND THERE USES SOIL COMPACTION EQUIPMENTS – ROLLER TYPES There are different types of rollers and other soil compaction equipments available. Use of these compacting machines depends on soil types and moisture conditions. Following are different types of Compaction Equipments for different soil types: The soil compaction equipments can be divided into two groups: 1. Light soil compacting equipments 2. Heavy soil compacting equipments 1. Light Soil Compacting Equipments: These equipments are used for soil compacting of small areas only and where the compacting effort needed is less. Below are light equipments for soil compaction: (i) Rammers: Rammers are used for compacting small areas by providing impact load to the soil. This equipment is light and can be hand or machine operated. The base size of rammers can be 15cm x 15cm or 20cm x 20cm or more. For machine operated rammers, the usual weight varies from 30kg to 10 tonnes (6 lbs to 22000 lbs). These hammers with 2- 3 tonnes (4400 to 6600 lbs)weights are allowed to free fall from a height of 1m to 2m (3ft to 7ft) on the soil for the compaction of rock fragments. Rammers are suitable for compacting cohesive soils as well as other soils. This machine in areas with difficulty in access. (ii) Vibrating Plate Compactors: Vibrating plate compactors are used for compaction of coarse soils with 4 to 8% fines. These equipments are used for small areas. The usual weights of these machines vary from 100 kg to 2 tonne with plate areas between 0.16 m2 and 1.6 m2. (iii) Vibro Tampers: Vibro tampers is used for compaction of small areas in confined space. This machine is suitable for compaction of all types of soil by vibrations set up in a base plate through a spring activated by an engine driven reciprocating mechanism. They are usually manually guided and weigh between 50 and 100 kg (100 to 220 lbs). 2. Heavy Soil Compaction Equipments: These compacting machines are used for large areas for use on different types of soils. The heavy compaction equipments are selected based on moisture content of soil and types of soil. Following are different types of these equipments: I) Smooth Wheeled Rollers: Smooth wheeled rollers are of two types: Static smooth wheeled rollers Vibrating smooth wheeled rollers The most suitable soils for these roller type are well graded sand, gravel, crushed rock, asphalt etc. where crushing is required. These are used on soils which does not require great pressure for compaction. These rollers are generally used for finishing the upper surface of the soil. These roller are not used for compaction of uniform sands. The performance of smooth wheeled rollers depend on load per cm width it transfers to the soil and diameter of the drum. The load per cm width is derived from the gross weight of the drum. The smooth wheeled rollers consists of one large steel drum in front and two steel drums on the rear. The gross weight of these rollers is in the range of 8-10 tonnes (18000 to 22000 lbs). The other type of smooth wheel roller is called Tandem Roller, which weighs between 6-8 tonne (13000 to 18000 lbs). The performance of these rollers can be increased by increasing the increasing the weight of the drum by ballasting the inside of drums with wet sand or water. Steel sections can also be used to increase the load of the drum by mounting on the steel frame attached with axle. The desirable speed and number of passes for appropriate compaction of soil depends on the type of soil and varies from location to location. About 8 passes are adequate for compacting 20 cm layer. A speed of 3-6 kmph is considered appropriate for smooth wheel rollers. Vibrating smooth wheeled rollers In case of vibrating smooth wheeled rollers, the drums are made to vibrate by employing rotating or reciprocating mass. These rollers are helpful from several considerations like:- (i) Higher compaction level can be achieved with maximum work (ii) Compaction can be done up to greater
Posted on: Sun, 16 Nov 2014 19:08:27 +0000
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