DETERMINATION OF FIELD DENSITY BY CORE CUTTER METHOD AN ACTIVE LEARNING ASSIGNMENT ON DETERMINATION OF FIELD DENSITY BY CORE CUTTER METHOD Prepared By: Tiwari Saurav D. 130180106119 Guided By : Prof. NEHA KAGRA 2014 GEOTECHNICS AND APPLIED GEOLOGY DEPARTMENT OF CIVIL ENGINEERING GOVERNMENT ENGINEERING COLLEGE, DAHOD

Content Theory Application Items required Procedure Result Precautions Reference

Theory:- Unit weight is the weight of soil per unit volume is called unit weight or density. It includes the whole soil mass, the solid particles plus all voids with or without moisture. It depends upon saturation ‘S’. since the dry unit weight of solids per unit of total volume of a soil mass is called dry unit weight. Volume = Ws/v gm/c.c. Field density is defined as weight of unit volume of soil present in site. That is Where, Density of soil W = Total weight of soil V = Total volume of soil

The soil weight consists of three phase system that is solids, water and air. The voids may be filled up with both water and air, or only with air, or only with water. Consequently the soil may be dry, saturated or partially saturated. In soils, mass of air is considered to be negligible, and therefore the saturated density is maximum, dry density is minimum and wet density is in between the two. Density or unit weight of soils may be determined by using the following method: i. Core cutter method ii. Sand replacement test iii. Rubber balloon test iv. Water displacement method v. Gamma ray method

Application:- Therefore density of soil deflects most of the properties of soil. Density of soil in place is compacted soil and used as quality control measured of earth work in embankment in place soil density of natural soil helps to determine bearing capacity, calculation of settlement as well as for stability analysis of natural slops.

Item required:- 1. Cylindrical core cutter of steel 127.4 mm long and 100 mm in width a metal thickness of 3 mm at one end. 2. Steel trolley 2.5 cm high and 10 cm internal diameter with wall thickness 7.5 mm. 3. Steel hammer. 4. Steel rule. 5. Straight edge. 6. Balance. 7. Container.

Hear we use core cutter method, the equipment arrangement is shown as fallows, Dolly Rammer Cutter

Procedure:- 1. The inside dimension of core cutter was measured accurately to 0.25 mm and calculated its volume. 2. The mass of the core cutter without trolley was measured accurately. 3. Exposed the small area about 30 sq.cm for test levelled that surface put the trolley on the top of the core cutter and drived the assembly into the soil with the help of hammer with the top of the dolly about 1 ½ cm above surface. 4. Dry weight the container from the surrounding soil and allowed some soil to project from the lower and of the cutter with the help of straight edge. 5. The mass of cutter face of soil was measured. 6. Kept some sample of soil for water content determination in the oven. 7. Repeat the test of the three location neat by end get the average density.

OBS. NO. DETERMINATION NO. 1ST READING 2ND READING 1 Mass of core cutter wet soil (gm) 2645gm 2580gm 2 Mass of core cutter (gm) 930gm 970gm 3 Mass of wet soil 1715gm 1670gm 4 Volume of core cutter (MR) 1021.0 cm³ 5 Bulk density P = ¾ g/cm3 1.68 kg/m³ 1.58 g/cm² 6 Bulk unit weight Y = 9.81 P 16.48 kg/m³ 15.5 kg/m³

7 Container no. A B 8 Mass of contain + wet soil 66 gm 37.3 gm 9 Mass of contain + dry soil 58 gm 34.5 gm

Precautions:- RESULTS:- 1.Percentage of water content = 24.35 % 2. Dry density of soil sample = 1.28 gm/cm³ 3. Dry weight of soil sample = 12.46 kg/m³ Precautions:- i. Steel dolly should be placed on the top of the cutter before ramming it down into the ground. ii. Core cutter should not be used for gravels, boulders or any hard ground. iii. Before removing the cutter, soil should be removed around the cutter to minimize the disturbances. iv. While lifting the cutter, no soil should drop down

REFERENCE:- http://civilatwork.blogspot.in/2013/07/determination-of-field-density-by-core.html?m=1 http://www.google.com/url?q=http://virtual-labs.ac.in/labs/CEVL/CEVL02-SM/Data%2520files/02%2520Unit_Weight.pdf&sa=U&ei=SbJxVL6ZF8fnuQTdnYCACw&ved=0CB4QFjAA&sig2=ooqLcCQ7_DUnq-ldxfRdPg&usg=AFQjCNF-o0Xas8I3Be6D3slo3IQBJePV8w