基坑支护设计

摘要本设计为办公大楼的基坑支护设计。本设计是根据国家现行建筑基坑支护技术规程,在给定地质勘察报告的条件下，进行基坑支护设计，主要目的是掌握基坑支护的设计方法。本设计采用了钻孔灌注桩加锚杆的基坑支护结构。在土压力计算过程中，运用了朗肯土压力理论；在内力计算过程中，运用了等值梁法；在配筋计算过程中，参照了混泥土结构设计规范;在降水处理设计时参照了建筑基坑支护技术规程；计算过程中除了以国家现行建筑基坑工程技术规程为依据外,还大量的把实际经验运用其中,加强理论与实践的结合。此次设计的主要指导原则是如何保证基坑的安全可靠、方便施工，并达到经济的效果。通过这篇论文，直观的说明了基坑支护设计所需的各种参数。工程技术人员在进行基坑支护设计时可参照本文的设计方法。[关键词]基坑支护；钻孔灌注桩；等值梁法；锚杆；降水处理AbstractThisdesignisthefoundationpitdesignforadistrict.Thedesignisbasedontheexistingnationalbuildingtechnicalreguations,excaration,geologicalsurveyinthegivenconditionsofthereportdesignfoundationpit.Themainpurposeofthedesignistograspthedesignmethodsoffoundationpit.Thedesignhasusedthefoundationpitmethodsofboredcaissonpilewithpile-anchor.Duringthecalculatingofsoilpressure,putthesoilpressuretheoriesofW.J.M.Rankinetouse;Inthecourseofcalculatingininternalforce,makeuseoftheequivalentbeammethod;whenmatchingthesteeltocalculate,havecomplywiththecementstructuredesignspecificationnorm;Inthedesignofdraining,makeuseofthetechnicalspecificationforretaining.Andstrengthenedthecombinationoftheactualexperiencewiththetheories.Theguidelineofthisdesignishowtoguaranteethefoundationpitsafe、reliable、convenienttoconstruct,andwhetherreachtheeconomicresultornot.Throughthispapers,wecanseevariouskindsofparametersthatareneededinthefoundationpitdesign.Engineersandtechnicianscanconsultthedesignmethodofthistextwhilecarryingonthefoundationpitdesign.[Keywords]foundationpit;boredcaissonpile;Equivalentbeammethod;pile-anchor;draining1目录1.前言....................................................................................................................................11.1工程概况.........................................................................................................................11.2本文主要研究内容.........................................................................................................22.工程地质与水文地质概况................................................................................................42.1场区工程地质条件........................................................................................................42.2水文地质条件................................................................................................................52.3基坑周边环境情况........................................................................................................63.基坑支护方案设计............................................................................................................73.1设计优选·....................................................................................................................73.1.1设计依据...............................................................................................................73.1.2基坑支护方案优选...............................................................................................73.1.3支护方案设计分析..............................................................................................93.2支护方案的设计原则及计算参数的确定..................................................................103.2.1设计原则.............................................................................................................103.2.2参数的初选.........................................................................................................104.基坑支护设计计算.........................................................................................................124.1基坑支护设计的主要内容..........................................................................................124.2设计计算......................................................................................................................124.2.1水平荷载的计算.................................................................................................134.2.2各层土的水平荷载计算.....................................................................................144.2.3水平抗力计算.....................................................................................................174.2.4各层土水平抗力计算.........................................................................................184.2.5支点力计算.........................................................................................................194.2.6嵌固深度验算.....................................................................................................214.2.7灌注桩结构设计.................................................................................................234.2.8桩身最大弯矩的计算.........................................................................................234.2.9桩身的配筋计算..................................................................................................244.3锚杆计算......................................................................................................................264.3.1锚杆设计主要内容.............................................................................................264.3.2锚杆设计.………………………………………………………………………264.3.3锚杆设计计算.....................................................................................................274.3.4腰梁设计.………………………………………………………………………354.4稳定性验算.