1基础工程课程设计名称梁板式筏形基础设计学院专业班级指导老师姓名学号年月2地基基础课程设计一、设计资料某建筑物双向板式片筏基础，上部结构传来的总轴力为总N=41012kN,基础埋深1.8m，修正地基承载力特征值fa=120kN/2m，混凝土强度等级用C20，钢筋用I、II级，试设计此基础。二、基础尺寸的确定1、按要求调整上部轴力值：41210-970119030NkN2、双向板式片筏基础是一种矩形基础。按公式：21190301417.0120-201.8aNAmfd所以：令220.14171431,31800,45000mmlbmmbmml。满足要求。3、地基净反力：2/18.838.3145119030mkNpj三、筏板基梁尺寸确定1、板厚的确定：梁板式筏基板厚不得小于300mm，且板厚与板格的最小跨度之比不宜小于20/1。取板厚为400mm，20/17200/400，满足要求。2、基梁尺寸的确定：基梁高按跨度的51-81估算，宽度按高度的21估算，故横梁尺寸取为600mm×1300mm，纵梁尺寸为600mm×1300mm。四、基础底板内力计算1、由《混凝土结构设计规范》（GB50010-2010），四边支承的混凝土板应按下列原则进行计算：当长边与短边长度之比小于或等于2.0时，应按双向板计算。图1：基础平面图32、计算步骤如下：NlpNlpyjxj424242421021.4312.710318.81045.299610318.8按双列连续板的区格3，区格4和区格5的计算简图，查教材（《地基基础设计与计算》朱浮生）表5-1~表5-5求得弯矩系数。675.0,0118.0,0244.05500.0,0295.0,0167.04806.0,0119.0,0283.04675.0,0178.0,0370.03,2.16/2.7/555444'4443331xyxxyxxyxxyxxyxxxxll：区格：区格：区格：区格计算板的各部位弯矩值如下：角格3mNlpMmNlpMyjyyxjxx442344231068.71021.4310178.01008.111045.2990370.0中间格4mNlpMmNlpMyjyyxjxx442444241013.51021.4310119.01047.81045.2990283.0中间格'4mNlpMmNlpMyjyyxjxx442444241085.121021.4310295.01000.51045.2990167.0''4中间格5mNlpMmNlpMyjyyxjxx442544251009.51021.4310118.01031.71045.2990244.0支座弯矩：mNlpxMmNlpxxMmNlpxMmNlpxxMxjxdxjxxcxjxbxjxxa4425442544424442431084.161045.29912675.0121078.171045.299)24675.016500.0()2416(1011.201045.29912806.0121067.221045.299)24806.016675.0()2416('mNlpxMmNlpxMmNlpxxMmNlpxxMxjyhyjygxjyyfyjyye4425442444254442431068.111021.43112675.01121097.171021.43112500.01121007.111021.431)24675.0116806.01()2416(1074.171021.431)24500.0116675.01()2416(''计算基础底板支座处的实际计算弯矩时，考虑横向和纵向基础梁宽度mb6.0的影响，需对弯矩进行调整。blpMxjxixi41blpMyjyiyi41从上述中得到支座弯矩调整值：mNblpxMMmNblpxMMmNblpxMMmNblpxMMxjxddxxjxccxxjxbbxxjxaax4454444444431079.1110)6.06318.8675.04184.16(411001.1410)6.06318.8500.04178.17(411008.1410)6.06318.8806.04111.20(411062.1710)6.06318.8675.04167.22(41'5mNblpxMMmNblpxMMmNblpxMMmNblpxMMyjxhhyyjxggyyjxffyyjxeey4454444444431076.810]6.02.7318.8)675.01(25.068.11[)1(411048.1310]6.02.7318.8)500.01(25.097.17[)1(411033.910]6.02.7318.8)806.01(25.007.11[)1(411082.1410]6.02.7318.8)675.01(25.074.17[)1(41'悬臂板的弯矩为：mNblpMj441099.410)26.05.1(2318.8)2(2五、基础梁内力计算1、作用在横梁JL1上的荷载，有悬臂板的均布地基净反力和边孔梯形荷载地基净反力之和，荷载计算简图：JL1荷载计算简图（尺寸单位：mm）悬臂板的荷载：mNpj/1048.125.110318.8441当时，mamNlpPxjj3,/1095.24310318.82/44梯形荷载的均布等量荷载为：mNPlalapjyyj/1009.181095.24)2.732.7321()21(44332233222因此，按均布荷载计算四跨连续梁的弯矩和剪力为：mNppjj/1057.3010)09.1848.12(4421支座弯矩：6mNlppMmNlppMyjjCyjjB4242214242211052.1122.71057.30071.0071.01057.1672.71057.30107.0107.0）（）（跨中最大弯矩：mNMMPlllpMmNMPlllpMCBjxyyjBjxyyj442222221max2442222221max11050.710)]252.11257.16795.242462.73(2.748.12036.0[)]2243(036.0[1004.10710)]57.1674.095.242462.73(2.748.12077.0[)]4.0243(077.0[剪力近似地按以下公式计算：mNlMMPllpQQmNlMMPllpQmNlMP...
