{"id":3609,"date":"2024-09-06T17:22:15","date_gmt":"2024-09-06T11:52:15","guid":{"rendered":"https:\/\/study.madeeasy.in\/?p=3609"},"modified":"2025-08-13T13:25:43","modified_gmt":"2025-08-13T07:55:43","slug":"bearing-capacity","status":"publish","type":"post","link":"https:\/\/www.madeeasy.in\/study\/ce\/soil-mechanics-foundation-engineering\/bearing-capacity","title":{"rendered":"Bearing Capacity"},"content":{"rendered":"<p style=\"text-align: justify;\">The load carrying capacity of foundation soil or rock which enables it to bear and transmit loads from a structure is know as bearing capacity.<\/p>\n<p style=\"text-align: justify;\">Some of the factors affecting bearing capacity are:<\/p>\n<ol>\n<li style=\"text-align: justify;\">Nature of soil and its physical and engineering properties.<\/li>\n<li style=\"text-align: justify;\">Nature of foundation and other details such as the size, shape, depth and rigidity of the structure.<\/li>\n<li style=\"text-align: justify;\">Location of the ground water table relative to the foundation level.<\/li>\n<li style=\"text-align: justify;\">The total and differential settlements that the structure can withstand without functional failure.<\/li>\n<li style=\"text-align: justify;\">Initial stress condition of the soil due to prehistory or due to the existing structure near proposed foundation.<\/li>\n<li style=\"text-align: justify;\">Nature and type of loading i.e. centric or eccentric.<\/li>\n<li style=\"text-align: justify;\">Mode of shear failure i.e. General, Local or Punching shear failure.<\/li>\n<\/ol>\n<h2 style=\"text-align: justify;\">MODE OF SHEAR FAILURE<\/h2>\n<p style=\"text-align: justify;\">The three principal modes of shear failure have been identified based on the model test of strip footings on sand, which are as follows:<\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_79_1 ez-toc-wrap-left counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.madeeasy.in\/study\/ce\/soil-mechanics-foundation-engineering\/bearing-capacity\/#1-General-shear-failure\" >1. General shear failure<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.madeeasy.in\/study\/ce\/soil-mechanics-foundation-engineering\/bearing-capacity\/#2-Local-shear-failure\" >2. Local shear failure<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.madeeasy.in\/study\/ce\/soil-mechanics-foundation-engineering\/bearing-capacity\/#3-Punching-shear-failure\" >3. Punching shear failure<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.madeeasy.in\/study\/ce\/soil-mechanics-foundation-engineering\/bearing-capacity\/#Ultimate-Bearing-Capacity-Equation\" >Ultimate Bearing Capacity Equation<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.madeeasy.in\/study\/ce\/soil-mechanics-foundation-engineering\/bearing-capacity\/#SKEMPTONS-METHOD\" >SKEMPTON\u2019S METHOD<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.madeeasy.in\/study\/ce\/soil-mechanics-foundation-engineering\/bearing-capacity\/#SETTLEMENT-OF-SHALLOW-FOUNDATIONS\" >SETTLEMENT OF SHALLOW FOUNDATIONS<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.madeeasy.in\/study\/ce\/soil-mechanics-foundation-engineering\/bearing-capacity\/#Settlement-Distribution-and-Contact-Pressure\" >Settlement Distribution and Contact Pressure<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.madeeasy.in\/study\/ce\/soil-mechanics-foundation-engineering\/bearing-capacity\/#BEARING-CAPACITY-OF-PILE\" >BEARING CAPACITY OF PILE<\/a><\/li><\/ul><\/nav><\/div>\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"1-General-shear-failure\"><\/span><strong>1. General shear failure<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul style=\"text-align: justify;\">\n<li>General shear failure is usually associated with medium to dense or stiff soils of relatively low compressibility.<\/li>\n<li>At the time of failure, most of the soil within stress zone reaches in plastic state except central portion.<\/li>\n<li>Main characteristics of general shear failure are : <img loading=\"lazy\" decoding=\"async\" class=\"alignright wp-image-3610 size-full\" src=\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/09\/shear-failure.jpg\" alt=\"Shear Failure\" width=\"328\" height=\"496\" srcset=\"https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/09\/shear-failure.jpg 328w, https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/09\/shear-failure-198x300.jpg 198w\" sizes=\"auto, (max-width: 328px) 100vw, 328px\" \/><br \/>\n(a) A well defined slip surface developed on both or one side of the footing.<br \/>\n(b) A sudden, catastrophic failure accompanied by tilting of foundation.<br \/>\n(c) Bulging of ground surface adjacent to the foundation before failure.<\/li>\n<\/ul>\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"2-Local-shear-failure\"><\/span>2. Local shear failure<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul style=\"text-align: justify;\">\n<li>Local shear failure is an intermediate failure mode characterized by well defined slip surface immediately below the footing but extending only a short distance into the soil mass.<\/li>\n<li>Since, the stress zone does not extend upto ground level. Therefore, only little bulging of soil around the footing is observed.<\/li>\n<li>Main characteristics of local shear failure are :<br \/>\n(a) Occurs in loose sands and soft clays in shallow foundations.<br \/>\n(b) Well defined wedge and slip surface only below the footing and no tilting and heaving is obtained on sides.<br \/>\n(c) Slip surface not visible beyond the edges of the foundation.<br \/>\n(d) Soil below footing is more stressed as compared to adjacent soil.<br \/>\n(e) When load v\/s settlement curve is plotted, progressive failure is obtained.<\/li>\n<\/ul>\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"3-Punching-shear-failure\"><\/span>3. Punching shear failure<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul style=\"text-align: justify;\">\n<li>Punching shear failure is usually associated with pile footings in loose sand or soft clays.<\/li>\n<li>The soil below the foundation is highly stressed which gets separated by vertical shear from adjacent soil. Hence, adjacent soil will remain unstressed.<\/li>\n<li>Main characteristics of punching shear failure are :<br \/>\n(a) Poorly defined failure planes<br \/>\n(b) Soil zone beyond the footing is not affected or little affected<br \/>\n(c) There are no tilting and heaving of adjacent ground but large settlement are recorded.<br \/>\n(d) When load v\/s settlement curve is plotted, progressive failure is obtained.<\/li>\n<\/ul>\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"Ultimate-Bearing-Capacity-Equation\"><\/span>Ultimate Bearing Capacity Equation<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul style=\"text-align: justify;\">\n<li>Ultimate bearing capacity of strip footing is given by the equation<\/li>\n<\/ul>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-3611 size-full\" src=\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/09\/bearing-capacity.jpg\" alt=\"Bearing Capacity\" width=\"666\" height=\"557\" srcset=\"https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/09\/bearing-capacity.jpg 666w, https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/09\/bearing-capacity-300x251.jpg 300w\" sizes=\"auto, (max-width: 666px) 100vw, 666px\" \/><\/p>\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"SKEMPTONS-METHOD\"><\/span>SKEMPTON\u2019S METHOD<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul style=\"text-align: justify;\">\n<li>Skempton proposed a simple expression for the net ultimate bearing capacity of saturated clay under undrained condition (\u03c6 = 0\u00b0)<\/li>\n<li>This theory can be applied for shallow as well as deep footings and the net ultimate bearing capacity is given by<\/li>\n<\/ul>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-3612 size-full\" src=\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/09\/bearing-capacity-1.jpg\" alt=\"Bearing Capacity\" width=\"667\" height=\"553\" srcset=\"https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/09\/bearing-capacity-1.jpg 667w, https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/09\/bearing-capacity-1-300x249.jpg 300w\" sizes=\"auto, (max-width: 667px) 100vw, 667px\" \/><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-3613 size-full\" src=\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/09\/skempton.jpg\" alt=\"Skempton\" width=\"729\" height=\"234\" srcset=\"https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/09\/skempton.jpg 729w, https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/09\/skempton-300x96.jpg 300w\" sizes=\"auto, (max-width: 729px) 100vw, 729px\" \/><\/p>\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"SETTLEMENT-OF-SHALLOW-FOUNDATIONS\"><\/span>SETTLEMENT OF SHALLOW FOUNDATIONS<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p style=\"text-align: justify;\">In shallow foundation total settlement can be divided into two parts<br \/>\n(i) Immediate settlement<br \/>\n(ii) Consolidation settlement<br \/>\nWe already discussed the methods to calculate above settlements<\/p>\n<h4 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"Settlement-Distribution-and-Contact-Pressure\"><\/span>Settlement Distribution and Contact Pressure<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p style=\"text-align: justify;\"><strong>(i) Flexible footing over clayey soil<\/strong><\/p>\n<ul style=\"text-align: justify;\">\n<li>In flexible footing, the contact pressure i.e. pressure at the interface between the footing and the soil is uniformly distributed.<\/li>\n<li>A uniform pressure produces a dish shaped pattern of displacement.<\/li>\n<\/ul>\n<p style=\"text-align: justify;\"><strong>(ii) Rigid footing over clayey soil<\/strong><\/p>\n<ul style=\"text-align: justify;\">\n<li>For rigid footings, the settlement has to be uniform over the contact area. Since, a flexible footing produces a dish shaped pattern in clay soil, the contact pressure must be more near the edge of the loaded area and less near centre, in order to produce a uniform settlement.<\/li>\n<\/ul>\n<p style=\"text-align: justify;\"><strong>(iii) Flexible footing over Granular soil<\/strong><\/p>\n<ul style=\"text-align: justify;\">\n<li>In granular soil, modulus of elasticity (E) varies across the width being maximum at the centre and minimum at edge. As E is maximum at centre, deflection is less at centre and E is less at edge, hence deflection is more at edge.<\/li>\n<\/ul>\n<p style=\"text-align: justify;\"><strong>(iv) Rigid footing over granular soil<\/strong><\/p>\n<ul style=\"text-align: justify;\">\n<li>For a rigid footing, where the settlement has to be uniform, the contact pressure is more near the centre than near the edges.<\/li>\n<\/ul>\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"BEARING-CAPACITY-OF-PILE\"><\/span>BEARING CAPACITY OF PILE<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul style=\"text-align: justify;\">\n<li>The ultimate bearing capacity of a pile is the maximum load which it can carry without shear failure (punching shear failure) or excessive settlement.<\/li>\n<li>Load on a pile is partially carried by skin friction and partially by the resistance offered by the soil at the base of the pile called point resistance.<\/li>\n<li>Therefore ultimate bearing capacity of a pile Q<sub>up<\/sub> is given by<br \/>\nQ<sub>a<\/sub> = Q<sub>eb<\/sub> + Q<sub>sf<\/sub><br \/>\nwhere, Q<sub>eb<\/sub> = Resistance due to end bearing or point resistance<br \/>\nQ<sub>sf<\/sub> = Resistance due to skin friction<\/li>\n<li>The bearing capacity of pile, also depends on the methods of installation.<\/li>\n<\/ul>\n<p style=\"text-align: justify;\"><strong>Allowable load on pile:\u00a0<\/strong><\/p>\n<ul style=\"text-align: justify;\">\n<li>The allowable load is the load which the pile can carry safely. It is equal to ultimate load on pile divided by FOS.<br \/>\nQ<sub>up\u00a0<\/sub><sub>=\u00a0<\/sub>Q<sub>up\u00a0<\/sub>\/ FOS<\/li>\n<li>FOS generally varies between 2.5 and 4.0, but a factor of safety of 2.5 is considered satisfactory.<\/li>\n<\/ul>\n<p style=\"text-align: justify;\"><strong>Piles in Clays<\/strong><\/p>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-3614 size-full\" src=\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/09\/clays.jpg\" alt=\"Clays\" width=\"797\" height=\"535\" srcset=\"https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/09\/clays.jpg 797w, https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/09\/clays-300x201.jpg 300w, https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/09\/clays-768x516.jpg 768w\" sizes=\"auto, (max-width: 797px) 100vw, 797px\" \/><\/p>\n<p style=\"text-align: justify;\"><strong>Pile in Sands<\/strong><\/p>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-3615 size-full aligncenter\" src=\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/09\/bearing-resistance.jpg\" alt=\"Bearing Resistance\" width=\"604\" height=\"286\" srcset=\"https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/09\/bearing-resistance.jpg 604w, https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/09\/bearing-resistance-300x142.jpg 300w\" sizes=\"auto, (max-width: 604px) 100vw, 604px\" \/><\/p>\n<p style=\"text-align: center;\"><a class=\"btn btn-danger\" role=\"button\" href=\"https:\/\/study.madeeasy.in\/ce\/soil-mechanics-foundation-engineering\/unconfined-compression-test\/\" target=\"_blank\" rel=\"noopener\">&lt;&lt; Previous<\/a> | <a class=\"btn btn-success\" role=\"button\" href=\"https:\/\/study.madeeasy.in\/ce\/soil-mechanics-foundation-engineering\/lateral-earth-pressure\/\" target=\"_blank\" rel=\"noopener\"> Next &gt;&gt;<\/a><br \/>\n<strong> Must Read: <\/strong> <a href=\"https:\/\/study.madeeasy.in\/ce\/soil-mechanics-and-foundation-engineering\/\" target=\"_blank\" rel=\"noopener\"><strong>Soil Mechanics and Foundation Engineering<\/strong><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The load carrying capacity of foundation soil or rock which enables it to bear and transmit loads from a structure<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[957,2],"tags":[1009,1011,1010],"class_list":["post-3609","post","type-post","status-publish","format-standard","hentry","category-soil-mechanics-foundation-engineering","category-ce","tag-mode-of-shear-failure","tag-pile-in-sands","tag-piles-in-clays"],"_links":{"self":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts\/3609","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/comments?post=3609"}],"version-history":[{"count":0,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts\/3609\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/media?parent=3609"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/categories?post=3609"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/tags?post=3609"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}