2019水电工程软弱土地基处理技术规范

水电工程软弱土地基处理技术规范TechnicalCodeforWeakSoilGroundTreatmentofHydropowerProjectsNB/T10343019目次12345总则......................................................................................................................................1术语......................................................................................................................................2基本规定..............................................................................................................................4工程地质勘察要点..............................................................................................................6地基计算..............................................................................................................................85.1荷载计算......................................................................................................................8.2地基承载力..................................................................................................................8.3地基变形.....................................................................................................................4地基稳定性................................................................................................................1255567压实地基............................................................................................................................146.1设计............................................................................................................................14.2施工............................................................................................................................14.3检验与监测................................................................................................................1566夯实地基............................................................................................................................167.1一般规定..............................................................................................................16.2设计............................................................................................................................16.3施工............................................................................................................................18.4检验与监测................................................................................................................1877789预压地基............................................................................................................................208.1一般规定..............................................................................................................20.2设计............................................................................................................................20.3施工............................................................................................................................25.4检验与监测................................................................................................................27888水泥粉煤灰碎石桩复合地基............................................................................................299.1一般规定..............................................................................................................29.2设计............................................................................................................................29.3施工............................................................................................................................31.4检验与监测................................................................................................................32999III10土挤密桩和灰土挤密桩复合地基..................................................................................3411110.1一般规定..................................................................................................................340.2设计..........................................................................................................................340.3施工..........................................................................................................................360.4检验..........................................................................................................................371111砂石挤密桩和砂石置换桩复合地基..............................................................................381.1一般规定..................................................................................................................381.2设计..........................................................................................................................381.3施工..........................................................................................................................401.4检验..........................................................................................................................412水泥土搅拌桩复合地基..................................................................................................43111111112.1一般规定..................................................................................................................432.2设计..........................................................................................................................432.3施工..........................................................................................................................442.4检验..........................................................................................................................453刚性桩复合地基..............................................................................................................4611113.1一般规定..................................................................................................................463.2设计..........................................................................................................................463.3施工..........................................................................................................................463.4检验..........................................................................................................................47114桩网结构复合地基..........................................................................................................481114.1设计..........................................................................................................................484.2施工..........................................................................................................................504.3检验与监测..............................................................................................................515高压喷射灌浆加固..........................................................................................................5211115.1一般规定..................................................................................................................525.2设计..........................................................................................................................525.3施工..........................................................................................................................535.4检验..........................................................................................................................5316注浆加固..........................................................................................................................55IV11116.1一般规定..................................................................................................................556.2设计..........................................................................................................................556.3施工..........................................................................................................................576.4检验..........................................................................................................................59117抛石挤淤..........................................................................................................................611117.1设计..........................................................................................................................617.2施工..........................................................................................................................627.3检验与监测..............................................................................................................628爆破挤淤..........................................................................................................................6411118.1一般规定..................................................................................................................648.2设计..........................................................................................................................648.3施工..........................................................................................................................678.4检验与监测..............................................................................................................68附录A软弱土地基处理方法..............................................................................................69附录B水土腐蚀性评价......................................................................................................70本规范用词说明......................................................................................................................74引用标准名录..........................................................................................................................75附：条文说明..........................................................................................................................76VContents12345GeneralProvisions...............................................................................................................1Terms....................................................................................................................................2BasicRequirements.............................................................................................................4KeyPointsofEngineeringGeologicalInvestigation...........................................................6FoundationDesignCalculation............................................................................................85.1LoadCalculation..........................................................................................................8.2BearingCapacityCalculation.......................................................................................8.3DeformationAnalysis..................................................................................................4Analysis........................................................................................................1255567CompactedGround............................................................................................................146.1Design.........................................................................................................................14.2Construction...............................................................................................................14.3InspectionandMonitoring.........................................................................................1466RammedGround................................................................................................................167.1GeneralRequirements................................................................................................16.2Design.........................................................................................................................16.3Construction...............................................................................................................18.4InspectionandMonitoring.........................................................................................18777891PreloadedGround...............................................................................................................208.1GeneralRequirements................................................................................................20.2Design.........................................................................................................................20.3Construction...............................................................................................................25.4InspectionandMonitoring.........................................................................................27888CompositeFoundationwithCement-Flyash-GravelColumns..........................................299.1GeneralRequirements................................................................................................29.2Design.........................................................................................................................29.3Construction...............................................................................................................31.4InspectionandMonitoring.........................................................................................329990CompositeFoundationwithCompactedSoilColumnsorCompactedLime-SoilColumns3410.1GeneralRequirements..............................................................................................34VI10.2Design.......................................................................................................................3410.3Construction.............................................................................................................3610.4InspectionandMonitoring.......................................................................................3711CompositeFoundationwithSqueezedSand-GravelColumnsorSand-GravelReplacementColumns..............................................................................................381.1GeneralRequirements..............................................................................................381.2Design.......................................................................................................................381.3Construction..............................................................................................................4011111.4InspectionandMonitoring........................................................................................412CompositeFoundationwithMixedCement-SoilColumns.............................................43111112.1GeneralRequirements..............................................................................................432.2Design.......................................................................................................................432.3Construction.............................................................................................................442.4InspectionandMonitoring.......................................................................................4513CompositeFoundationwithRigidPiles...........................................................................4611113.1GeneralRequirements..............................................................................................463.2Design.......................................................................................................................463.3Construction.............................................................................................................463.4InspectionandMonitoring.......................................................................................47114CompositeFoundationwithPile-ReinforcedEarth.........................................................481114.1Design.....................................................................................................................484.2Construction.............................................................................................................504.3Inspection.................................................................................................................50JetGroutingReinforcement...........................................................................................525.1GeneralRequirements..............................................................................................525.2Design.......................................................................................................................525.3Construction.............................................................................................................535.4Inspection.................................................................................................................5351111116GroutingReinforcement...................................................................................................5511116.1GeneralRequirements..............................................................................................556.2Design.......................................................................................................................556.3Construction.............................................................................................................576.4InspectionandMonitoring.......................................................................................597SqueezingSludgeFillingStones.................................................................................61VII17.1Design.......................................................................................................................6117.2Construction.............................................................................................................6217.3InspectionandMonitoring.......................................................................................6218SqueezingSludgeBlasting..........................................................................................6411118.1GeneralRequirements..............................................................................................648.2Design.......................................................................................................................648.3Construction.............................................................................................................678.4InspectionandMonitoring.......................................................................................68AppendixASoilGroundMethods.............................................................69AppendixBSoilsandErosionEvaluation..................................................................70ExplanationofinThisCode..................................................................................74ListofQuotedStandards......................................................................................................75Addition:ExplanationofProvisions....................................................................................76VIII1总则111.0.1为规范水电工程软弱土地基处理的设计、施工和检验的技术要求，制定本规范。.0.2本规范适用于水电工程软弱土地基处理。.0.3的规定。-2术语2.0.1软弱土地基weaksoilground构成的地基。同义词：软基。.0.2地基承载力特征值characteristicvalueofsubsoilbearingcapacity地基载荷试验获得的压力—值为比例界限值。22.0.3压实地基compactedground采用平碾、振动碾、冲击碾或其他碾压设备将填土分层密实处理的地基。.0.4夯实地基rammedground2和振动能量，形成密实地基或置换墩体的地基。2222.0.5压实系数compactionfactor土的控制干密度与最大干密度的比值。.0.6堆载预压preloadingwithoffill地基上堆加荷载使地基土固结压密的处理方法。.0.7真空预压vacuumpreloading采用抽真空使地基土排水固结的处理方法。.0.8水泥粉煤灰碎石桩复合地基compositefoundationwithcement-flyash-gravelcolumns由水泥、粉煤灰、碎石等混合料加水拌合在土中钻孔灌注形成桩体的复合地基。.0.9灰土挤密桩复合地基compositefoundationwithcompactedlime-soilcolumns用灰土填入孔内，分层夯实，使周围土挤密，并形成竖向增强体的复合地基。.0.10砂石挤密桩复合地基compositefoundationwithsqueezedsand-gravelcolumns22复合地基。2水泥土搅拌桩复合地基compositefoundationwithmixedcement-soilcolumns-的复合地基。2.0.12抛石挤淤squeezingsludgebyfillingstones在软基上抛填片石或块石，依靠抛石的重力挤出淤泥并形成堆石体的方法。.0.13爆破挤淤squeezingsludgebyblasting2底部滑塌，挤开软土形成抛石置换体的方法。2.0.14高压喷射灌浆jetgrouting技术。2.0.15注浆加固groutingreinforcement通过水力劈裂和渗入，将水泥浆或其他浆液注入地基土中，增强土颗粒间的联结，使土体强度提高、变形减小、渗透性降低的方法。2.0.16垫层夯填度compactiondegreeofcushion垫层压实或夯实后的厚度与虚铺厚度的比值。-3基本规定3.0.1和节约资源。.0.2土地基处理方法宜按本规范附录A选用。3.0.3软弱土地基处理方案制定前，应完成下列工作：3123456789收集岩土工程勘测资料。取得上部结构和基础设计资料。收集水文气象资料。评价水和土对建筑材料的腐蚀性。调查邻近建（构）筑物、地下工程、周边道路、管线设施等。掌握施工条件并了解施工场地的周边环境。根据工程要求，分析天然地基存在的问题。确定处理的目的和需要达到的技术指标。调查当地软基处理经验，了解其他地区类似场地同类工程的软基处理经验。3.0.4软弱土地基处理方案的制定应按下列步骤进行：考虑工程地质条件、周边环境、施工条件等因素，初步选择技术可行的处理方案。对初选的方案，宜结合耐久性、经济性、工期、潜在风险、环境影响等因素进行技术经济综合比较，选择处理方案。1234对选择的处理方案，宜选择有代表性的区域进行现场施工试验。应根据现场施工试验成果，调整设计参数，完善处理方案。3.0.5应满足下列要求：12当荷载影响范围内存在软弱下卧层，应验算软弱下卧层的地基承载力。按地基变形设计或应作变形验算且需进行地基处理的建（构）筑物，应对处理后的地基进行变形验算。3用于堤坝、堆场、填土路堤、土石围堰、土石坝等工程的地基，应验算地基稳-定性。45对承受水平荷载或位于斜坡上的地基，应验算地基稳定性。对深埋的闸坝、渠道、涵闸等工程的地基，应分析可能的破坏模式，验算地基稳定性。.0.6水平荷载作用要求。.0.7进行检验。.0.8333承载力评价，进行质量检测和验收。3.0.9检验应符合下列规定：1对采用多种方法处理的地基，应采用大尺寸承压板进行载荷试验，处理后的地基承载力应满足设计要求。2检验点的布置应具有代表性，宜随机、均匀布置检验点；对重要部位、局部岩土特性复杂的部位和施工出现异常的部位，应加密布置检验点。3检验点间距和深度，应根据采用的软弱土地基处理方法及其影响范围、施工技综合确定。4当采用一种检验方法的检测结果存在非确定性时，宜采用其他方法进行综合检验。33.0.10检验结果不满足设计要求时，应分析原因，提出处理措施。施工监测应结合建（构）筑物布置、基础型式、软基处理方案、周边环境等，制定监测方案。.0.12软弱土地基处理对周边环境有影响时，应对邻近建（构）筑物、邻近地下管线以及周围地面进行变形监测，并对施工过程的振动和噪声进行监控。.0.13软弱土地基处理的技术资料应反映工程勘察、设计、施工、检验与监测的实际情况，并应与其他资料一并进行整理、组卷与归档。33-4工程地质勘察要点4.0.1软弱土地基处理工程地质勘察应符合下列要求：搜集附有坐标及地形的建筑总平面布置图，了解建筑物性质、规模、荷载、结构、基础特点、地下管线、周边环境及规划情况、设计要求。查明软弱土地基处理范围内及下卧地层的种类、成因类型、沉积时代、空间分布及物理力学性质。控制性勘探孔的深度应满足地基沉降和稳定性验算的要求。查明场地的水文地质条件，查明地下水的化学性质、埋藏条件、流向、流速、123水位，并查明场地水和土的腐蚀性。4查明邻近建筑物、构筑物、地下管线等周边环境情况，评价软弱土地基处理对周边环境的可能影响，提出防护措施建议。查明大粒径块石、地下洞穴、植物残体、管线、障碍物等可能影响软弱土地基处理施工的因素，并评价其对软弱土地基处理方案的影响。5678查明区域不良地质作用。提出地层物理力学参数及水文地质参数建议值。对处理方案和施工试验提出建议。4.0.2软弱土地基处理所需的主要物理力学指标可按表4.0.2选取。表4.0.2软弱土地基处理所需的主要物理力学指标序号软弱土地基处理方法压实地基、夯实地基常规指标其他指标12最优含水率、最大干密度p预压地基含水率、孔隙345级配、渗透系置换桩复合地基黏性土的有效抗剪强度指标土挤密桩和灰土挤密桩复合地基、数、压缩模量、砂石挤密桩复合地基指标承载力特征值阻力、桩端阻力水泥土搅拌桩复合地基-续表4.0.2软弱土地基处理所需的主要物理力学指标序号软弱土地基处理方法常规指标其他指标6高压喷射灌浆、注浆加固刚性桩和桩网复合地基抛石挤淤、爆破挤淤黏性土的超固结比、有机质含量黏性土的不排水抗剪强度、黏性土的超固结比、无黏性土的有效抗剪强度指标、桩侧摩阻力、桩端阻力78灵敏度、不排水抗剪强度4.0.3参数取值应考虑取样方法和其他因素对试验结果的影响，评价其代表性和可靠性。-5地基计算5.1荷载计算5.1.1三类。.1.25荷载、可变荷载、偶然荷载的代表值应符合现行行业标准《水工建筑物荷载设计规范》DL5077的规定。5.1.3工建筑物荷载设计规范》DL5077确定的标准值或代表值。.1.4现的荷载，采用各自最不利的组合进行设计，且应符合下列要求：验算地基承载力时，传至基础或承台底面上的荷载效应应按正常使用极限状态下荷载的标准组合；相应的抗力应采用地基承载力特征值或单桩承载力特征值。计算地基变形时，传至基础或承台底面上的荷载效应应按正常使用极限状态下荷载的标准组合，不应计入风荷载和地震作用；相应的限值应为地基变形允许值。验算挡土墙、地基或滑坡稳定以及基础抗浮稳定时，承载能力极限状态的持久5123设计状况和短暂设计状况应采用基本组合，偶然设计状况应采用偶然组合。永久荷载、DL5077的规定采用，相应的抗力采用地基土体抗剪强度标准值。5.1.5组合。5.2地基承载力.2.1计规范的要求。.2.2地基承载力验算应符合下列规定：551当作用于地基上的压力为轴心荷载时，应符合下式要求：kfa(5.2.2-1)式中：pk——相应于荷载效应的标准组合时，作用于地基上的平均压力值（kPa-fa——修正后的地基承载力特征值（kPa2当作用于地基上的压力为偏心荷载时，尚应符合下式要求：kfa(5.2.2-2)式中：pkmax——相应于荷载效应的标准组合时，作用于基础底面边缘处地基上的最大压力值（kPa5.2.3程经验综合确定。当基础宽度大于3m或埋置深度大于0.5m时，从载荷试验或其他原并采用下式计算：fafb3d(5.2.3)bdm式中：f地基承载力特征值(kPa)，对复合地基用f表示；akspkηη——bd筑地基基础设计规范》GB50007和《建筑地基处理技术规范》JGJ79的有关规定；b——基础宽度（3m时按3m取值，大于6m时按6m取值；d——基础埋置深度（γm——3效重度；γ——基础底面以下土的重度（kN/m35.2.4复合地基承载力特征值应根据现行国家标准《复合地基技术规范》GB/T50783式计算：fkλ/A+kλ(1-)fsk(5.2.4-1)(5.2.4-2)(5.2.4-3)(5.2.4-4)(5.2.4-5)(5.2.4-6)spkppapssfβ/A+β(1-)fspkpapsβ=kλpppβ=kλsss=d2/d2es=η0de式中：fspk——复合地基承载力特征值(kPa)；-kp——复合地基中桩体实际竖向抗压承载力的修正系数；λp——桩体竖向抗压承载力发挥系数；Ap——单桩截面积2)；Ra——单桩竖向抗压承载力特征值(kN)；ks——复合地基中桩间土地基实际承载力的修正系数；——复合地基置换率；λs——桩间土地基承载力发挥系数；fsk——桩间土地基承载力特征值(kPa)；βp——桩体竖向抗压承载力修正系数；d——桩体直径(m)；s——桩的间距；η0——形状系数，正三角形布桩为0.952，正方形布桩为0.886；de——单根桩分担的地基处理面积的等效圆直径(m)；βs——桩间土地基承载力修正系数。5.2.5的单桩竖向抗压承载力特征值可按本规范公式(5.2.5-1)计算；由桩体材料强度提供的单桩竖向抗压承载力特征值可按本规范公式(5.2.5-2)计算；两者应取小值。napqlqA(5.2.5-1)(5.2.5-2)ippi1RfAap式中：up——桩的截面周长(m)；n——桩长范围内所划分的土层数；qsi——第i层土的桩侧摩阻力特征值(kPa)；li——桩长范围内第i层土的厚度(m)；qp——桩端土地基承载力特征值(kPa)；α——桩端土地基承载力折减系数；fcu——桩体抗压强度平均值(kPa)；η——桩体强度折减系数。5.2.6-10-式计算：RKA(5.2.6)app式中：σru——桩周土所能提供的最大侧限力(kPa)；Kp——桩周土被动土压力系数。5.2.7建筑地基基础设计规范》GB50007的有关规定验算。《5.3地基变形.3.1情况分析确定，满足结构安全和正常运行要求。55.3.2地基沉降由加固区土层压缩量和下卧土层压缩量组成，可按下式计算：s12(5.3.2)式中：s——地基沉降量（s1——加固区土层压缩量（s2——下卧土层压缩量（5.3.3计算方法：1ni1i(5.3.3-1)(5.3.3-2)s1i11mE式中：s1加固区土层压缩量（ψs1——加固区沉降计算经验系数；Δpi——第i层土的平均附加应力增量（kPali——第i层土的厚度（Espi——第i层土的复合压缩模量（MPa——复合地基置换率；-11-Epi——第i层桩体的压缩模量（MPaEsi——第i层桩间土的压缩模量（MPa刚性桩处理的复合地基，可按下式计算：21p(5.3.3-3)pAp式中：ψp——桩身压缩经验系数，根据桩长径比、桩端土层情况结合地区经验取值；——刚性桩顶部附加荷载（kNl——桩长（Ep——桩体压缩模量（MPaAp——单桩截面积（23采用压实、夯实、注浆、预压、挤淤方法处理的地基，可按下式计算：np1ii(5.3.3-4)i1式中：ψs1——加固区沉降计算经验系数；Δpi——第i层土的平均附加应力增量（kPali——第i层土的厚度（Esi——加固区第i层土的压缩模量（MPa.3.4下卧土层的压缩量，可按下式计算：5np2ii(5.3.4)s2i1式中：s2——下卧土层压缩量（ψs2——下卧层沉降计算经验系数；Δpi——第i层土的平均附加应力增量（kPali——第i层土的厚度（Esi——第i层土的压缩模量（MPa5.3.5对变形计算有专门规定的水电工程建筑物，应采用相应的设计规范计算。5.4地基稳定性55.4.1地基稳定性应根据可能的破坏模式和工况进行验算。.4.2数取值应匹配。-12-5.4.3均质地基稳定性分析可采用圆弧滑动法，稳定安全系数可按下式计算：MRSK(5.4.3)式中：K——稳定安全系数；MR——抗滑力矩（kN·mMS——滑动力矩（kN·m5.4.4复合地基稳定性分析方法宜根据增强体类型选用。-13-6压实地基6.1设计6.1.1散填土地基宜采用振动压实法，采用振动压实法时宜降低地下水位至振实面600mm以下。6.1.2坚硬、性能稳定、无腐蚀性和无放射性危害的工业废料等。不应使用未经处理的淤泥、耕土、冻土、膨胀土以及有机质含量大于5%的土料。6.1.3验或不合格的压实填土不应作为建筑地基持力层。6.1.4行行业标准《碾压式土石坝设计规范》DL/T5395的有关规定选用。66.1.5压实地基下卧层承载力验算应符合本规范第5.2.7条的规定。.1.6压实地基的变形可根据本规范第5.3.2条~5.3.4条的方法计算，其压缩模量可通过处理后地基的原位测试或取样土工试验确定。.1.7定性、承载力和变形满足设计要求。.1.8效加固深度等，通过现场试验确定压实工艺、碾压范围、施工控制参数。666.2施工.2.1150mm2/3粉质黏土和粉土作填料时，其施工含水率宜控制在最优含水率偏差±2%的范围内。.2.2集中填土。6666.2.3压实施工时，应对邻近建筑物和地下管线的影响进行评估。.2.4压实施工时应采用地面排水，可设置斜坡排水或地面排水沟等措施。-14-6.3检验与监测.3.1压实地基的承载力可通过现场静载荷试验检验，并可结合动力触探、静力触探、标准贯入试验综合判定。666.3.2压实地基的施工质量应按设计要求分层检验，检验合格后方可进行下一道工序。.3.3502~1002面积内不应少于1个检测点。6.3.4压实施工时，宜对地基进行变形监测。-15-7夯实地基7.1一般规定77.1.1夯实地基可采用强夯法和强夯置换法等方法。.1.2加固效果。试验区数量应根据场地地质条件、工程规模、工程类型及施工工艺等确定。土质条件对试夯场地进行检测，通过强夯前后的对比确定施工工艺及其参数。7.1.3合其他方法的综合处理方案。.1.4措施。77.2设计7.2.17.2.2强夯的有效加固深度应根据现场试夯击或地区经验确定。缺少试验资料或经验时，可按现行行业标准《建筑地基处理技术规范》JGJ79的有关规定预估。.2.3强夯设计应符合下列规定：夯点布置可根据基础底面形状、地基土构成和有效加固深度确定，可采用等腰三角形、正方形或其它布置形式，圆形基础可采用环形布置。夯点间距可根据建筑结构类型、需加固土层厚度和土质条件等因素综合确定，712对厚度大和土质差的软弱土层第一遍夯点间距宜为5间距宜为3m~6；第二遍宜在第一遍夯点中间加密点夯。3单点夯击数应根据现场试夯的夯击次数和夯沉量的关系曲线确定，并应同时满足下列规定：12）最后两击的平均夯沉量，宜符合现行行业标准《建筑地基处理技术规范》JGJ79的有关规定，当单击夯击能大于12000kN·m时，应通过试验确定。）夯坑周围地面不应发生过大的隆起。-16-3）不因夯坑过深而发生提锤困难。4前后两遍夯击间隔时间应根据地层中超孔隙水压力的消散状况确定，当缺少实弱土层较厚、渗透性较差的黏性土和粉土，宜间歇7d~14d。5夯击遍数应根据地基土的性质和使用要求确定，宜采用2遍~4遍。点夯后宜再以低能量满夯1遍~2遍。6夯击范围应大于需加固地层的范围，每边夯锤中心超出的宽度宜为有效加固深度的1/2，并不宜小于3。当要求消除地基液化时，在基础外缘扩大宽度不应小于基底下可液化土层厚度的1/2，且不宜小于5。对独立柱基，可采用柱下单点夯。7.2.4夯，并应符合下列规定：12宜铺填一定厚度的砂石垫层，使地下水位低于起夯面以下3。降水深度及降水持续时间应根据土质条件和地基有效加固深度确定，并应在降水期间监测地下水位，应严格控制强夯时地下水位的深度。强夯施工宜夯击3遍~4遍，单击夯击能可从500kN·m逐级增大到1000kN·m及以上。34强夯间歇时间宜根据软土中超静孔隙水压力消散80%以上所需时间或工程经验确定。7.2.5强夯置换设计应符合下列规定：粒径大于300mm的颗粒含量不宜超过全重的30%；施工前可在松软土层上铺填.0m~2.0m厚的砂石垫层。强夯置换墩的深度应根据土质条件确定，宜穿透软土层，深度不宜超过10m。112置换墩施工后，墩顶应铺设一层厚度不小于500mm的压实垫层，垫层材料宜与墩体材料相同。3墩位布置宜采用等腰三角形、正方形布置，或按基础型式布置。墩间距应根据地基变形和地基承载力特征值要求选定。强夯置换单击夯击能及夯点的夯击次数应通过现场试验确定，并应使墩底穿透4理技术规范》JGJ79的有关规定。-17-5强夯置换设计时，应预估地面隆起值，并通过试夯校正。.2.6应通过现场单墩复合地基静载荷试验确定。.2.7夯实地基变形计算应符合本规范第5.3.2条~5.3.5条的规定。夯后有效加固深度内土层的压缩模量应通过原位测试或土工试验确定。777.3施工7.3.1强夯处理地基施工，强夯夯锤质量宜为10t~6025kPa~80kPa通的排气孔，孔径宜为300mm~400。7.3.2强夯置换地基施工设备的选用应符合下列规定：1强夯机的起重能力可按锤重和落距确定。宜采用起重能力为15t以上的履带式起重机或其它专用设备，起吊高度宜为5