11第11章节—桩与桩基.ppt

第 11 章桩和桩基 Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. 主要内容?概述?单桩承载力的确定?群桩的承载力?桩基承台计算 Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. 第1节概述一、桩基及其作用 Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. ?桩基构成:桩+承台(可为独立、条形、筏、箱)有高、低两种,前者用于水中; ?桩之作用: (1)将荷载传至硬土层,或分配到较大的深度范围,以提高承载力。(2)减小沉降,从而也减小沉降差,故地基强度够, 而变形不合要求时亦用。(3)抗拔:用于抗风、抗震、抗浮等( 4)有一定抗水平荷载能力,特别是斜桩( 5)抗液化:深层土不易液化,浅层土液化后,有桩支撑,有助于上部结构的稳定。 Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. 2、特点: (1)承载力高; (2)稳定性好; (3)沉降小; (4)便于机械化施工。桩基础已成为建筑、交通、水利、港口等工程中广为采用的基础形式。单柱单桩基础 Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. 3、应用桩基础主要通过作用于桩尖土层的阻力和桩周土的摩阻力来支承轴向荷载,也可利用桩侧土的侧向阻力抵抗水平荷载。通常遇以下情况时可选用桩基础: (1) 对地基沉降要求严格,不允许有不均匀或过大沉降的建筑物; (2) 采用地基加固措施不合适的软弱地基或特殊土地基; Evaluation only. Evaluation only. Created with Client Profile . Created with 3