HOW TO CALCULATE SAFE BEARING CAPACITY OF SOIL ON SITE?

<div dir="ltr" style="text-align: left;" trbidi="on"> <div style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin-bottom: 20px; padding: 0px; vertical-align: baseline;"> <img alt="How to calculate safe bearing capacity of soil on site" class="aligncenter size-full wp-image-2200" height="224" src="http://civilblog.org/wp-content/uploads/2015/02/How-to-calculate-safe-bearing-capacity-of-soil-on-site.jpg" style="border: 0px; clear: both; display: block; float: none; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; height: auto; line-height: inherit; margin: 1em auto; max-width: 100%; padding: 0px; vertical-align: baseline;" title="HOW TO CALCULATE SAFE BEARING CAPACITY OF SOIL ON SITE?" width="448" /></div> <div style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin-bottom: 20px; padding: 0px; vertical-align: baseline;"> This simple and quick field test will give you a rough idea of bearing capacity of soil.</div> <h2 style="background-color: white; border: 0px; color: #2a2a2a; font-family: 'Droid Sans', sans-serif; font-size: 24px; font-stretch: inherit; line-height: 1.4; margin: 0px 0px 12px; padding: 0px; text-transform: uppercase; vertical-align: baseline;"> <span style="border: 0px; color: #00ccff; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">PROCEDURE</span></h2> <ol style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin: 1.5em 0px 1.571em 1.9em; padding: 0px; vertical-align: baseline;"> <li style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">Excavate a pit of required depth. (preferably equal to the depth of foundation)</li> <li style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">Take a solid ball or square cube of known weight and dimension.</li> <li style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">Drop the ball or square cube several times, from a known height on to the bottom surface of excavated pit.</li> <li style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">Calculate the average depth of impression made several times on the bottom surface of the excavated pit. Let “d” is the average depth of impression.</li> </ol> <h2 style="background-color: white; border: 0px; color: #2a2a2a; font-family: 'Droid Sans', sans-serif; font-size: 24px; font-stretch: inherit; line-height: 1.4; margin: 0px 0px 12px; padding: 0px; text-transform: uppercase; vertical-align: baseline;"> <strong style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="border: 0px; color: #00ccff; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">CALCULATION</span></strong></h2> <div style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin-bottom: 20px; padding: 0px; vertical-align: baseline;"> Calculate the ultimate resistance of soil ( R ) using the formula given below.</div> <div style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin-bottom: 20px; padding: 0px; vertical-align: baseline;"> <strong style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">R = (w * h) / d</strong></div> <div style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin-bottom: 20px; padding: 0px; vertical-align: baseline;"> Where,</div> <div style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin-bottom: 20px; padding: 0px; vertical-align: baseline;"> R = Ultimate resistance of soil (in kg)</div> <div style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin-bottom: 20px; padding: 0px; vertical-align: baseline;"> d = Average depth of impression (in cm)</div> <div style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin-bottom: 20px; padding: 0px; vertical-align: baseline;"> w = Weight of the solid ball or square cube (in kg)</div> <div style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin-bottom: 20px; padding: 0px; vertical-align: baseline;"> h = Height of fall of solid ball or cube (in cm)</div> <div style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin-bottom: 20px; padding: 0px; vertical-align: baseline;"> If “A” is the cross-sectional area of the solid steel ball or cube, then resistance of soil per unit area is calculated using following formula.</div> <div style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin-bottom: 20px; padding: 0px; vertical-align: baseline;"> Resistance of soil per unit area (in kg/cm<span style="border: 0px; bottom: 1ex; font-family: inherit; font-size: 10px; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; height: 0px; line-height: 1; margin: 0px; padding: 0px; position: relative; vertical-align: baseline;">2</span>) = R / A</div> <div style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin-bottom: 20px; padding: 0px; vertical-align: baseline;"> Safe bearing capacity (in kg/cm<span style="border: 0px; bottom: 1ex; font-family: inherit; font-size: 10px; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; height: 0px; line-height: 1; margin: 0px; padding: 0px; position: relative; vertical-align: baseline;">2</span>) = R / (A * F.O.S)</div> <div style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin-bottom: 20px; padding: 0px; vertical-align: baseline;"> Where,</div> <div style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin-bottom: 20px; padding: 0px; vertical-align: baseline;"> F.O.S = Factor of safety</div> <h3 style="background-color: white; border: 0px; color: #2a2a2a; font-family: 'Droid Sans', sans-serif; font-size: 22px; font-stretch: inherit; line-height: 1.4; margin: 0px 0px 12px; padding: 0px; text-transform: uppercase; vertical-align: baseline;"> <span style="border: 0px; color: red; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">NOTES TO REMEMBER</span></h3> <ol style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin: 1.5em 0px 1.571em 1.9em; padding: 0px; vertical-align: baseline;"> <li style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">F.O.S varies from 2 to 3 depending upon the type of structure and site condition.</li> <li style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">In order to get reliable test result, perform this test on different types of soil and then use your judgment to reach at any conclusion.</li> <li style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">Instead of using solid steel ball or square cube, we can also use CBR test plunger, or Cone (used for cone penetration test)</li> </ol> <h2 style="background-color: white; border: 0px; color: #2a2a2a; font-family: 'Droid Sans', sans-serif; font-size: 24px; font-stretch: inherit; line-height: 1.4; margin: 0px 0px 12px; padding: 0px; text-transform: uppercase; vertical-align: baseline;"> <strong style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="border: 0px; color: #00ccff; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">PRESUMPTIVE BEARING CAPACITY</span></strong></h2> <div style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin-bottom: 20px; padding: 0px; vertical-align: baseline;"> The table given below shows the presumptive bearing capacity values for different types of soils. This table will guide you to reach at any conclusion after conducting the test.</div> <table style="background-color: white; border-collapse: collapse; border-spacing: 0px; border: 1px solid rgb(221, 221, 221); color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin: 0px 0px 25px; padding: 0px; vertical-align: baseline; width: 621px;"><tbody style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"> <tr style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399"><strong style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">Type of Soil / Rock</strong></td><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399"><strong style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">Safe / Allowable Bearing Capacity (kg/cm<span style="border: 0px; bottom: 1ex; font-family: inherit; font-size: 10px; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; height: 0px; line-height: 1; margin: 0px; padding: 0px; position: relative; vertical-align: baseline;">2</span>)</strong></td></tr> <tr style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399">Rock</td><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399">32.40</td></tr> <tr style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399">Soft rock</td><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399">4.40</td></tr> <tr style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399">Coarse sand</td><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399">4.40</td></tr> <tr style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399">Medium sand</td><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399">2.45</td></tr> <tr style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399">Fine sand</td><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399">4.40</td></tr> <tr style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399">Soft shell / Stiff clay</td><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399">1.00</td></tr> <tr style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399">Soft clay</td><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399">1.00</td></tr> <tr style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399">Very soft clay</td><td style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 7px 15px; vertical-align: baseline;" width="399">0.50</td></tr> </tbody></table> <h3 style="background-color: white; border: 0px; color: #2a2a2a; font-family: 'Droid Sans', sans-serif; font-size: 22px; font-stretch: inherit; line-height: 1.4; margin: 0px 0px 12px; padding: 0px; text-transform: uppercase; vertical-align: baseline;"> <span style="border: 0px; color: red; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">NOTES TO REMEMBER</span></h3> <ol style="background-color: white; border: 0px; color: #555555; font-family: 'Droid Sans', sans-serif; font-size: 14px; font-stretch: inherit; line-height: 23px; margin: 1.5em 0px 1.571em 1.9em; padding: 0px; vertical-align: baseline;"> <li style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">For non-cohesive soils the values should be reduced by 50% if the water table is above or near base of footing.</li> <li style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">These values should be used only for preliminary design. The actual bearing capacity of soil should be calculated as per the standard codes.</li> </ol> <div> <span style="color: #555555; font-family: Droid Sans, sans-serif; font-size: xx-small;"><span style="line-height: 23px;">Main post from: http://civilblog.org/</span></span></div> </div>

HOW TO CALCULATE SAFE BEARING CAPACITY OF SOIL ON SITE?

This simple and quick field test will give you a rough idea of bearing capacity of soil. PROCEDURE Excavate a pit of required depth....

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