第1页：土的三相组成
- Chapter 10 Soil Mechanics and FoundationSection A Characteristics of Soils（土力学与地基基础）（土的特征）Physical propertySoil is usually composed of three phases: solid, liquid, andgas.The mechanical properties of soils depend directly onthe interactions of these phases with each other and withapplied potentials (e.g., stress,hydraulic([hai‘drɔ:lik]adj.水力的；水力学的；液压的，水压的；水工的)head, electrical potential, andtemperature difference).
- 物理性质土通常由三相组成：固相，液相，气相。
土的力学性质依赖于这三相间的相互作用以及其他因素，诸如压力的变化，水头的变化，电位的变化或温度的不同。
第2页：土中的液相
- Theliquidphaseinsoilsiscommonlycomposedofwatercontainingvarioustypesandamountsofdissolvedelectrolytes([i'lektrəʊlait]n.电解物，电解质，电解液).Organiccompounds,bothsoluble(['sɔljubl]adj.可溶解的)andimmiscible([i'misəbl]adj.不能混合的，不融洽的)arepresentinsoilsfromchemicalspills([spil]n.溢出，流；v.溢出，洒，使...流出),leakingwastes,andcontaminatedgroundwater.
- 土中液相通常是由水和不同类型、不同数量的溶解电解质组成。
土中的有机物，可溶物和不溶物都在来自化学物泄漏，废弃物和污染的地下水。
第3页：气相与矿物成分
- The gas phase, in partiallysaturated(['sæt∫əreit]vt.使浸透,使渗透，使湿透，使饱和；使充满)soils, is usually air, although organicgases may be present in zones of high biological activity or inchemically contaminated soils.
- 气相，在非饱和土中存在，通常指的是空气，虽然在一些生物活性大或化学污染的土壤中存在一些有机气体。
- Soil mineralogy controls the size, shape, and physical andchemical properties of soil particles and thus its load-carryingability and compressibility.
- 土的矿物成份决定的土中颗粒的大小，形状，和物理化学性质，因此决定了其承载能力和压缩性。
第4页：土的变形形式
- Soil, like any other engineering material,distorts([dis'tɔ:t]v.扭曲)when placed under a load. Thisdistortion([dis'tɔ:ʃən]n.扭曲，变形，曲解)is of two kinds-shearing, or sliding, distortionand compression.In general, soils cannot withstandtension(['tenʃən]n.紧张；张力，拉力). In some situations theparticles can be cemented together and a small amount oftension may be withstood, but not for long periods.
- 像其他任何工程材料一样，土受力后会变形。
这种变形有两种：剪切或滑动变形，不均匀沉降或压缩变形。一般情况下，土体不承受拉力。在某些情况下，由于颗粒间的粘结，土体可能承受较小的拉力，但也不能长时间承受。
第5页：有效应力原理
- Effective stress(有效应力)The concept of effective stress is one of Karl Terzaghi'smost important contributions to soil mechanics.It is ameasure of the stress on the soil skeleton (the collection ofparticles in contact with each other), and determines theability of soil to resistshear stress(切变应力，剪应力，切应力，粘性摩擦应力).It cannot be measured in itself, but must becalculated from the difference between two parameters thatcan be measured or estimated with reasonable accuracy.
- 有效应力有效应力概念的提出是太沙基在土力学这门学科中做出的最重要的贡献之一。
它是描述土骨架所承受的压力大小，有效应力本身不能量测得反应了土体抵抗剪切应力的能力。到，但是可以从其他两个量测的或估计的有合理的准确性的参数的差来计算出。
第6页：孔隙水压力
Theporewaterpressureuisthepressureofthewateronthatplaneinthesoil,andismostcommonlycalculatedasthehydrostatic([haɪdrə'stætɪks]adj.流体静力学的，流体静压力的)pressure.Forstabilitycalculationsinconditionsofdynamicflow(undersheetpiling,beneathadamtoe,orwithinaslope,forinstance),umustbeestimatedfromaflownet.Inthesituationofahorizontalwatertableporewaterpressureincreaseslinearlywithincreasingdepthbelowit.孔隙水压力u是水在这个平面上的压力，常用于计算静水在动水作用下有关稳定性的计算（如钢板桩的计算、压力。坝脚下方，或斜坡）中，孔隙水压力u
必须要根据净流量来估计。同一水平面时，孔隙水压力随着深度的增加而线性增大。
第7页：抗剪强度的工程意义
- Shear strengthMost problems ingeotechnics(土工学，地质技术学，地质工学),e.g. bearing capacity of shallow and deep foundations, slopestability, retaining wall design,penetration([peni'trei∫ən]n.渗透,贯穿，穿透(深)度，渗透性)resistance, soilliquefaction([͵likwi'fæk∫ən]n.液化(作用)etc., are affected by the soil shearstrength.Analytical and numerical analyses use values ofshear strength for solving these engineering problems.
- 抗剪强度岩土工程中的多数问题，如浅基础和深基础的稳定性问题、边坡稳定问题、挡土墙设计、防渗问题、土壤液化等，都是由土的抗剪强度所决定的。
分析抗剪强度这个参数可解决这些工程问题。
第8页：抗剪强度的形成机理
Shearingstrengthinsoilsistheresultoftheresistancetomovementatinterparticlecontacts,duetoparticleinterlocking,physicalbondsformedacrossthecontactareas(resultingfromsurfaceatomssharingelectronsatinterparticlecontacts),andchemicalbonds.
土中抗剪强度是抵抗颗粒间相互运动的结果，抗剪强度的形成是由于颗粒间的嵌锁作用，以及沿着接触面上形成物理键，化学键的作用使的颗粒之间有粘结力.
第9页：土组成与状态的影响
- The stress-strain relationship of soils, and therefore theshearing strength, is affected by:土的应力应变关系，土的抗剪强度，受以下因素影响：◆soil composition (basic soil material): mineralogy, grainsize and grain size distribution, shape of particles, pore fluidtype and content, ions on grain and in pore fluid.
- 土的组成的影响：包括矿物成份，粒径及粒度成份，颗粒形状，孔隙流体类型及含量，颗粒表面及孔隙流体中的离子。
- state (initial): State can be describe by terms such as: loose,dense, overconsolidated, normally consolidated, stiff, soft,contractive,dilative([daɪ`leɪtɪv,dɪ-]adj.膨胀的,膨胀性的,有扩张作用的), etc.
- 初始状态的影响：状态可用下列指条目来描述如：疏松，密实，超固结，正常固结，硬，软，收缩，膨胀等。
第10页：加载条件的影响
- Loadingconditions:Effectivestresspath-drained,undrained,andtypeofloading-magnitude,rate(static,dynamic),andtimehistory(monotonic,cyclic).
- ◆加载条件的影响：加载的有效应力路径，排水，不排水，加载量，加载速率，应力历史。
第11页：土的固结
- ConsolidationConsolidation is a process by which soils decrease in volume.It occurs when stress is applied to a soil that causes the soilparticles to pack together more tightly,therefore reducing volume.When this occurs in a soil that is saturated with water, water willbe squeezed out of the soil. The magnitude of consolidation canbe predicted by many different methods.In the Classical Method,developed by Karl Terzaghi, soils are tested with an oedometertest to determine their compression index. This can be used topredict the amount of consolidation.
- 固结固结是土体体积减少的一个过程，当土壤受到压力时会发生，固结后，土中颗粒排列会更紧密，因此土体体积减小。
当饱和土固结时，水会排出。固结的程度可用不同的方法来在太沙基提出的经典的方法，可通过固结试验来确定预测。其压缩系数。这可以用来预测固结的程度。
第12页：侧向土压力的分类
- Lateral earth pressureLateral earth stress theory is used to estimate the amount ofstress soil can exert perpendicular to gravity. This is the stressexerted onretaining walls（挡墙，挡土墙，护壁）.A lateral earthstress coefficient, K, is defined as the ratio of lateral (horizontal)stress to vertical stress forcohesionless（[kəu‘hi:ӡənlis]adj.非粘结性的）soils (K=σh/σv).There are three coefficients: at-rest,active, and passive.
- 侧向土压力侧向土压力理论是用来计算垂直于重力的横向压力的的大小。
- K，是用来定义无粘性土的侧向及水平向应力与竖向应力的的比值(K=σh/σv).
- 有三种土压力：静止土压力，主动土压力，被动土压力。
第13页：三种土压力的定义
- At-rest stress is the lateral stress in the ground before anydisturbance takes place.The active stress state is reachedwhen a wall moves away from the soil under the influence oflateral stress, and results from shear failure due to reduction oflateral stress.The passive stress state is reached when a wallis pushed into the soil far enough to cause shear failure withinthe mass due to increase of lateral stress.There are manytheories for estimating lateral earth stress; some areempirically based, and some are analytically derived.
- 主动土压力是指当墙体在侧向压力作用下背离土体方向移动时，使墙后土体达到极限平衡状态时产生的土压力；静止土压力是土体没有任何位移时产生的侧向土压力；被动主压力是指在压力作用下墙体向着土体方向移动使墙后土体达到极限平衡状态时有许多理论来估算土压力，有一些是以经验为基础的的土压力。
，有一些是理论分析得到的。
第14页：地基承载力与破坏模式
- Bearing capacityThe bearing capacity of soil is the average contact stress between afoundation and the soil which will cause shear failure in the soil. Allowablebearing stress is the bearing capacity divided by a factor of safety.Sometimes, on soft soil sites, large settlements may occur under loadedfoundations without actual shear failure occurring; in such cases, theallowable bearing stress is determined with regard to the maximum allowablesettlement.
- 承载能力土体的承载能力是指土体与基础之间的平均接触应力，是土体能够承受的最大的剪应力。
- Three modes of failure are possible in soil: general shear failure, localshear failure, andpunching（[‘pʌntʃ]n.打洞器,钻孔机,冲压机,冲床；vt.开洞,冲压打孔）shear failure.
- 土体破坏的模式有：整体剪切破坏，局部剪切破坏，冲切破坏。
有时，在软土地区，加载后土体实际没有发生剪切破坏，在这种情况下，允许承载力就是由建筑物允许的最大变形来控制。
第15页：Section B 斜坡上的基础
- Section B Foundations on Slopes（边坡上的基础）IntroductionThe design of foundation for structures on oradjacent([ə'dӡeisənt]adj.接近的，附近的，毗连的，相邻的)to slopes musttake into account the interaction between the structure andthe slope.
- 引言设计在斜坡上或是与斜坡相邻结构基础时，一定要考虑结构与斜坡的相互作用。
Twocriteria([krai'tiәriә]n.标准)must be considered:(1) the influence of the adjacent slope on the bearing capacistyand settlement of the foundation, and(2) the effect the foundation will have on the stability of the slope.必须要考虑两条准则：（1）相邻斜坡对基础承载力和沉降的影响，以及（2）该影响反过来对斜坡稳定性的影响
第16页：斜坡基础的两条准则
- Thefirstcriterionrecognisesthattherecanbeasignificantreductioninbearingcapacity(bothhorizontallyandvertically)duetoanadjacentslope(Vesic,1975;Poulos,1976;Schmidt,1977)andthesecondcriterionisimportantbecausethestabilityofaslopecanbeaffectedbyexcavationfortheconstructionoffoundationsonoradjacenttotheslope,theloadimposedbyfoundationsonorabovetheslope,orthetemporaryorpermamentchangeingroundwaterregime([rei'ӡi:m]n.状态，方式)causedbyconstructionofthefoundation.
- 第一条准则研究结果表明，由于毗邻斜坡的影响，承载力（水平和竖直方向）能够较大程度降低；第二条很重要，因为在斜坡上或与斜坡毗邻的基础的开挖、基础产生的荷载、或因基础施工产生的地下水短期或长期的变化，都能够影响边坡的稳定性。
第17页：香港的典型基础形式
- Typical foundation types in Hong Kong are spreadfootings,caissons(['keisən]n.沉箱)(hand-dug and machinebored) and piles (percussion([pə:'kʌ∫ən]n.冲击，撞击，碰击),bored,precast(['pri:'kɑ:st]vt.现浇制；adj.预制(的)，预浇铸(的))andcast-in-place(现浇)).Spread footings and hand-dugcaissons are the most common because heavy machinery isnot required for construction, the operation of which isdifficult on steep hillsides.
- 在香港，典型的基础形式包括扩展基础、沉箱（人工挖掘及机械钻挖）以及桩基础（冲击、钻孔、预制和现浇）。
因为重型机械很难在陡坡上进行施工操作，所以扩展基础和人工挖掘沉箱是最常见的基础形式。
第18页：浅基础与深基础的适用条件
- Shallow foundation (spread footings) are used for light loads,and deeper foundations (piles) are used where the bearingstratum(['streitəm]n.层，地层，阶层)is at depth or where thestabillity of the slope would be impaired by any additional loadfrom the foundation.
- 浅基础（扩展基础）适用于轻负载情况，较深基础（桩基础）则适用于持力层较深或边坡稳定性因基础传来附加荷载而削弱的情况。
第19页：斜坡上浅基础的极限承载力
Shallow foundationsBearing capacity and settlementTheultimate bearing capacity(极限承载力)of a shallowfoundation on a slope is lower than that for the same footingon level ground.A general expression for the ultimatebearing capacity of such foundations is reproduced fromGeoguide 1 (Geotechnical Control Office, 1982) to whichreference should be made
浅基础承载能力与沉降与水平地面上相比，斜坡上浅基础的极限承载能力要低。这种基础极限承载能力的通式在岩土指南第一册（土力工程处，1982）中再次提出，该指南：
第20页：坡顶后移与影响因素
(1) for guidance on the particular problem of estimating thebearing capacity of a foundation set-back from thecrest([krest]n.顶，山顶，浪峰，最高水位)of a slope, and(2) for a discussion of other factors that can influence bearingcapacity.（1）
对从坡顶后移基础承载能力的特殊问题做出了评价，以及（2）探讨了其他能够影响承载力的因素
第21页：不同高度基础的相互影响
- Whereshallowfoundationsareconstructedatmorethanonelevelonaslope,thefoundationsatthehigherlevelmayimposeadditionalloadingonthelowerones.Thisadditionalloadingmustbetakenintoaccountinthedesign.
- 在斜坡的不同高度施工浅基础时，较高位置的基础要对位置较低的基础产生附加荷载。
设计当中一定要考虑此附加荷载。
第22页：斜坡整体稳定性
- Ingeneral,bearingcapacitycalculationsdonotallowfor(考虑)thefactthatthesoilformingtheslopeisalreadyunderstress,andsoitisimportanttoassesstheoverallstabilityoftheslopeundertheinfluenceoftheloadedfoundation.However,anacceptablefactorofsafetyagainstslopefailure(抗破坏安全系数)obtainedfromastabilityanalysisthatincludestheinfluenceoffoundationloads,doesnotnecessarilymeanthatthefoundationisacceptableintermsofsettlement.
- 通常，计算承载力不考虑土壤形成边坡所受到的应力，所以，在负荷基础影响下考虑斜坡整体稳定性是很重要的。
然而,土坡抗破坏安全系数符合要求，并不一定意味着沉降也满足要求，而土坡抗破坏安全系数是经过包括基础荷载影响的稳定分析得到的。
第23页：边坡稳定性的验算条件
Slope StabilityAs a general rule, the stability of a slope affected byfoundations should be checked if the slope angle is greater thanΦ’/2 (Vesic, 1975).Where this is so, the foundation can beconsidered as an equivalent line load or asurcharge([sə:'t∫ɑ:dӡ]n.超载，负荷过重，过度的负担，过度的充电)imposing horizontal andvertical loads and incorporated into the stability analysis.边坡稳定性一般而言，如果坡角大于Φ’/2时，应当检验受基础影响的边坡稳定性(Vesic, 1975)。
此时，基础可以看做是等效线荷载，或施加水平和竖向荷载的附加荷载，一并纳入稳定性分析。
第24页：张拉裂缝与反向断面
- Thebackfilling(回填)to a foundation may be poor, and sothe stability analysis should consider the possibility of a tensioncrack forming on the upslope-edge of the foundation.For shallow foundations on or above rock slopes, thestability analysis should take into account potential instabilitydue to adversely orientateddiscontinuities(['dis͵kɔnti'nju(:)iti]n.中断，间断，突变性，突变点). The analytical methods of Hoek＆Rray (1981) are useful in this respect.
- 基础回填土的力学性能较差，所以，稳定性分析应当考虑在基础的边坡上边缘形成张拉裂缝的可能性。
当浅基础位于岩石边坡处或上方时，稳定性分析应当考虑反向断面引起的潜在不稳定性。在这方面，Hoek＆Rray(1981)使用的分析方法很有用。
第25页：开挖与支撑的影响
- The stability of a slope can be impaired by excavation for theconstruction of shallow foundations on or adjacent to the slopeand the demolition of structures supporting the toe of the slope.Both these effects should be considered during the analysis.Inorder to minimise the short term instability of a slope,excavations should be as small as possible and should beproperlyshored([∫ɔ:,∫ɔə]n.
- (房屋、树木等的)支柱，斜撑柱).边坡处或边坡上方浅基础的开挖，以及边坡底部结构支撑的拆除，都可以削弱边坡的稳定性，而且边坡短期稳定性。
为了降低边坡短期不稳定性，开挖应当尽可能少，而且还应适当设置支撑。
第26页：深基础的水平荷载
- Deep FoundationsLateral LoadsThe horizontal stresses in a soil slope vary throughout theslope and, for deep foundations, the horizontal loading on theupslope side of the foundation is larger than on the downslopeside.However, in a slope that has an acceptable factor of safetyagainst failure, the difference in horizontal load is negligible(Schmidt,1977) and need not be considered during the design ofmost deep foundations.
- 深基础水平荷载对于深基础来说，土坡中的水平应力在整个边坡范围内是不同的，而且基础在上坡所受的水平荷载大于下坡处。
然而，在边坡抗破坏安全系数满足要求情况下，可以忽略水平荷载大小的差异（Schmidt, 1977），而且在大多数深基础设计中都不需要考虑。
第27页：地层运动下的高侧向荷载
- However,highlateralloadingcanbetransferredtofoundationsinsituationswherethereissignificantgroundmovement(i.e.wheretheslopeaboveorbelowthefoundationfailsorwheretheslopeinfrontofthefoundationisexcavated)orwherethereisonlyasmallgroundmovement(i.e.creep)butwherethefoundationisverystiff.
- 然而，当地层发生显著运动（即基础上方或下方边坡坍塌，或基础前方边坡遭挖掘）或地层运动很小（即蠕动）而基础刚度非常大时，高侧向荷载能够传递给基础。
第28页：单桩横向荷载分析方法
- Various methods of analysis are available for theanalysis of single piles subjected to lateral loading due toground movement. Wang＆Yen (1974) and Ito＆Davis(1977) use limiting equilibrium methods and suggest ways inwhich arching between closely-spaced piles can beconsidered.Poulos＆Davis (1980) use finite differencemethods; these, however, are very dependent on the correctdefinition of the stress-strain characteristics of the soil layerssurrounding the piles (De Beer,1977).
- 由于土的运动引起的对单桩横向荷载的分析有多种方法。
Wang＆Yen (1974)和Ito＆Davis (1977)使用了极限平衡方法，建议考虑加密桩之间土的隆起方式。Poulos＆Davis(1980)使用了有限差分方法；然而，这些方法取决于桩体周围土层应力-应变关系的正确定义（De Beer, 1977）。
第29页：减轻土体运动的两项措施
Where possible, lateral loads on deep foundations should beprevented. This can be achieved by either:(1)stabilising([`steɪbɪlaɪz]v.(使)稳定，(使)安定，(使)坚固)potentiallyunstable slopes before construction of the foundation, or(2) by the provision of anannular(['ænjulə]adj.环的，环形的)sleevearound the foundation.
- （1）基础施工前，加固潜在不稳定边坡，或
- （2）基础周围准备环状套管。
第30页：环状套管的构造
- An annular sleeve is a space of sufficient width betweenthe foundation and the surrounding soil so that both can movewithout interaction. The space, which can be air filled or cancontain a suitable compressible material, must be wide enoughto accommodate the ground movements expected and thedeflection of the foundation itself.
- 环状套管是基础和其周围土壤之间足够宽的区域，该区域内可以充气，也可以填充可压缩材料，而且必须足够宽，从而缓解土的运动及基础偏移。
第31页：充气区域内衬要求
- For air-filled spaces, when alining(['lainiŋ]n.衬，衬套，套筒，衬垫，隔板)has to be used to support the soil, the lining mustprevent theingress(['inɡres]n.进入，入口)of groundwater orsurface water into the space and must prevent the spacefilling up with soil.The plug at the top of the air-gap betweenthe lining, and the foundation should be designed so that thereis no load transmitted through it.
- 对于充气区域来说，当必须使用内衬时，内衬必须阻止地下水及地表水进入该区域，而且还要防止土壤进入。
应当设计介于内衬与基础之间空气隙顶端塞头，使得不能通过它来传递荷载。
第32页：可压缩材料的填充设计
- For spaces that are filled with a compressible material, thedesign width should take into account the compressibility ofthe material itself, especially as a result of the placement ofwet concrete(塑性混凝土)during construction.In such circumstances, it may be appropriate to install theannulus(['ænjuləs]n.环，环形物，环轮，环状空间，环形套筒)eccentrically around the foundation with the centre of theannulus upslope of the centre of the foundation.
- 对于内部填充可压缩材料，设计宽度应当考虑材料自身的压缩性，尤其是塑性混凝土浇筑的时候。
在那种情况下，可在基础外围安装环形套管，但要确保套管的中心处在基础中心的上坡位置。
第33页：深基础对边坡稳定的影响
Slope StabilityDeep foundation can adversely affect the stability of slopes:(1) by transmitting vertical or horizontal loads to the slope,(2) by the removal of support during the excavation forconstructioon of the foundation, or(3) by the temporary or permanent change in thegroundwater regime caused by the foundation.
- （1）通过将竖向或水平荷载传递给边坡
- （2）通过基础开挖施工过程中支撑的移除，或
- （3）通过基础施工引起地下水暂时或永久性状态的变化。
第34页：阻断荷载传递的措施
- To prevent the transmission of vertical loads onto a slope,the founding depth for a deep foundation should be belowany potential failure plane whthin the slope.To prevent thetransmission of horizontal loads, an annular sleeve shouldbe provided.In this case, the annulus may be installedeccentrically around the foundation, but with the centre ofthe annulus downslope of the centre of the foundation.
- 为阻止竖向荷载传给边坡，深基础的浇筑深度应当低于边坡内任何潜在坍塌面的位置。
为阻止水平荷载的传此时，套管的安装要偏离基础，递，应当采用环状套管。使套管中心在基础中心的下坡位处。
第35页：边坡稳定性的评定
- Where these measures are not possible and loads fromthe foundation are likely be transmitted to the slope, thestability of the slope under the influence of these loads shouldbe assessed.However, this assessment is not easy as themethods usually adopted for stability analysis (limit equilibriummethods) are not compatible with those used to evaluate soilpressures (elastic methods).
- 在不能采取这些措施而且基础传来的荷载有可能传给边坡时，应当评定在这些荷载影响下边坡的稳定性。
然而，这种评定不容易，因为稳定性分析常采用的方法（极限平衡法）不适合于评价土压力（塑性方法）。
第36页：整体透水性下降的影响
When caissons or piles are closely spaced, there may bea reduction in overallpermeability([͵pə:miə'biliti]n.透过性，可透[渗]性，渗透(性,度,率))that would result in a rise in thegroundwater level upslope of the foundation (Pope＆Ho,1982).This possibility must be considered in the design, andany assumptions made should be checked by the installationand monitoring ofpiezometers([paiə'zɔmitə]n.流压计，水压计，压力计，压强)after the foundation is in place.当沉箱或桩分布很密时，整体透水性能的下降会导致基础上坡位地下水位的上升（Pope＆Ho, 1982）。
设计时一定要考虑该可能性，而且任何做出的假设都应在基础施工完成后，通过测压计的安装和监测进行核实。
第37页：桩基与沉箱支护边坡
Piles and caissons can be used to support slopes, andmethods for their design in these situations are given byGould (1970) and Fukuoka (1977).
桩基和沉箱可以用来支护边坡，这种情况下结构的设计方法由Gould (1970)和Fukuoka (1977)给出。
