桩

Then the pile-soil stress characteristics and stabilizing mechanism of the composite foundation are fully discussed. Based on the close analysis of the influence factors of the vertical bearing capacity, circular aperture extension theory is employed to establish the computing formulas for the pile vertical stress and the foundation vertical bearing capacity, respectively. Moreover, with analyzing the features of the calculation parameters such as materials of gunite mortar, jet pressure, diameter of the jet pipe, pile length, pile layout, a design theory for chemical churning pile composite foundation is proposed. Then, the variation of the pipe deformation with loads, the deformation coordination of pile and soil are studied. And methods to decide pile-soil stress ratio and the compressive modulus are developed. Meanwhile, the corresponding design method and the design parameters are proposed. In addition, studies for construction technique and quality detection of the chemical churning pile composite foundation are presented.

在此基础上深入探讨了旋喷桩的桩土受力特性及其复合地基的加固机理，从影响旋喷桩复合地基竖向承载力的因素入手，基于圆孔扩张理论给出了桩体竖向应力及旋喷桩复合地基的竖向承载力计算公式；通过对喷射浆液、喷射压力选取、喷射直径估算、桩长及桩位设计等各种计算参数的深入分析和研究，提出了一套相应的旋喷桩复合地基设计计算方法；通过计算分析，深入探讨了旋喷桩复合地基变形随荷载变化规律、桩和桩间土变形协调关系、桩土应力比及复合地基压缩模量的确定，并提出相应的设计方法和修正参数；此外，结合工程应用，对旋喷桩复合地基的施工技术及其现场质量检测方法进行了较全面的探讨。

Reinforced Mixing Pile which is made of two complementary material is introduced, which congeals in the water soil agitation the beginning of pile inserts certain length the core pile,forms the compound stress pile one kind of new pile,had the core pile participation, enhanced the pile body rigidity and the section supporting capacity,causes display which the water soil the limiting condition side friction and the pile body concrete material strength may coordinate balanced,thus obtains the high single pile limit supporting capacity.

劲性搅拌桩是在水泥土搅拌桩初凝前插入一定长度的芯桩，形成复合受力桩的一种新桩型，有了芯桩的参与，提高了桩身刚度和截面承载力，使水泥土的极限状态侧摩阻力和桩身混凝土的材料强度可以均衡协调的发挥，从而获得较高的单桩极限承载力。大量工程实践证明，该桩型具有承载力高、造价低、桩身质量稳定可靠、施工工艺简单和环保效益好等优点。

Under the condition of the slide between pile and soil around pile is taked into account,five equations are established, including the equation of compatibility between the settlement of pile cap soil and the settlement of pile cap; the equation of compatibility between the settlement of pile head soil and the settlement of pile head; the physical equation between the settlement of soil around pile shaft and the settlement of pile shaft;the equation of equilibrium between loads on the pile cap, side frictional stress and restraints of pile head; the equation of compatibility between the deformation of the pile body and the subtraction between the settlement of pile cap and the settlement of pile heap.

桩身单元和土单元存在着相互作用，在允许桩土相对滑移的前提下，建立桩顶土体沉降与桩顶沉降的协调方程、桩底土体沉降与桩端沉降的协调方程、桩土相对位移与桩侧摩阻力的物理方程、桩身力的平衡方程、桩身压缩和桩顶沉降与桩端沉降之差的协调方程。

The primary studying works and characteristics:1 To summarize reinforcing theory of cement mixing pile composite foundation2 To analyze the primary mechanics characters and changing rules of cement mixing pile, based on analysis of test data both indoor and outdoor.3 To discuss siding frictional resistance, ending resistance, ultimate bearing capacity of simple mixing pile and effectiveness factor of grouped piles, loading ratio of soil between piles under cushion cap of grouped piles and stress ratio of pile and soil and so on, and use many computation method and experimentation method to ensure bearing capacity of mixing piles composite foundation.4 To point out and analyze eight sides flaws and problems of the bearing capacity calculation method of mixing pile compositefoundation which ensured by national and normative method/ formula.5 To apply test results of loading tests and a few settlement observation data, use gray theory to predicate ultimate bearing capacity of deep mixing piles, actual example demonstrate engaging between theoretical predicted value and actual value.6 To apply groovy layerwise summation method to discuss entity piles method, double foundation method, equivalent layerwise summation method and consolidation theoretical method and so on, especially by combination of engineering example, use FEM to calculate or discuss the settlement and changing rules of composite foundation.7 To discuss problems of critical length of composite foundation by combination of engineering example and numerical analysis method, and analyze the contrast of critical length between simple pile load and most area load of composite foundation, not only critical length of composite foundation is relative to modulus ratio between piles and soil, but also upside load distribution area of composite foundation.

主要的研究工作与特色为：(1)总结了水泥搅拌桩复合地基的加固原理；(2)在对室内外试验资料进行统计分析的基础上，系统分析了搅拌桩水泥土的主要力学特性及其变化规律；(3)探讨了搅拌单桩的侧摩阻力、端阻力、极限承载力及群桩效率系数、群桩承台下桩间土荷载分担比及桩土应力比等，提出用多种计算方法并结合试验方法来综合确定搅拌桩复合地基的承载力；(4)明确指出和分析了按国家有关规范的方法确定搅拌桩复合地基承载力所存在的八个方面的缺陷与问题；(5)利用过去没有加载至破坏阶段的载荷试验成果和较少的沉降观测数据，尝试了用灰色理论预测深层搅拌桩的极限承载力，实例表明理论预测值与实测值吻合较好；(6)在常规分层总和法的基础上，探讨了复合地基沉降计算的实体墩基法、双层地基法、等效作用分层总和法、固结理论法等，特别是结合工程实例，用有限元数值计算等方法计算和讨论了搅拌桩复合地基的沉降及其变化规律；(7)结合工程实例，用数值分析方法探讨了复合地基临界桩长的问题，指出和分析了单桩荷载下的临界桩长与复合地基大面积荷载下的临界桩长存在很大的差别，复合地基的临界桩长不仅与桩土模量比有关，而且与复合地基上部荷载分布面积有关。

The capacity of single pile will enhance when the length and diameter of pile increases, but effect of pile diameter is more obvious. While pile diameter increases 20、40 and 60 percents, the capacity of pile will enhance 20.4、53.7 and 78.1 percents. And with the effect of mud-cake, the capacity of single bored pile will fall down nearly 20 percents, and pile-side resistance will also reduce 15 — 35 percents. In the centrifuge tests, when the relative displacement between pile and soil was 45 —85mm, which is much more than the criterions, the pile-side resistance will become most. Meanwhile the intenerated value of utmost resistance is close to the resistance in situ. In the pile group tests, the capacity of pile group , which the space among piles increases from 2D to 3D、 4D and 5D , will enhance 6.1、9.6、18 percents .

当桩径增加20%、40%、60%时，桩承载力分别增长了20.4%、53.7%和78.1%；在考虑泥皮效应后单桩侧摩阻力减小15～35%，极限承载力减小18%～24%，且减小率随桩径的增加而变小；试验中桩身侧阻软化值与原型桩实测侧阻软化值接近，且极限侧阻所对应的桩土相对位移试验要比规范值大得多，约为45～85mm；同时群桩极限承载力随桩距的增大而增加，其中桩距为3D、4D、5D的群桩承载力分别比间距为2D的群桩高6.1%、9.6%和18%；其承载力效应系数η接近或大于1，并随着桩间距的增大而不断提高；群桩侧摩阻力沿深度的分布与单桩略有不同，即桩身上部由于承台的作用，侧阻削弱，但桩身中部侧阻具有增加的趋势。

General procedures for measuring highway as follows: First check the correctness of the original data, including principal point coordinates, distance, azimuth,桩号miles, round curves, relaxation curves and vertical curve elements of the curve, more than longitudinal slope and the slope design of high, ultra high and wide, and draw good draft for field use.

公路测量的程序一般为：首先校核原始资料的正确性，主要包括主点坐标、距离、方位角、里程桩号、圆曲线、缓和曲线和竖曲线的曲线要素、纵坡和边坡坡比、设计高、超高和加宽等，并画好草图以备外业使用。

In this paper, on the basis of the description of the pile-driving process and the dynamic analysis of the pile and the HSPD, the relationship between the frequency and the pile-driving force has been established under the conditions of the pile strength and the HSDP working requirements. The frequency character of the ZYB200B HSPD system has been analyzed quantitatively in the vibrancy pile-driving process, therefore the frequency range and the best available frequency have been obtained.

本文首先通过对压桩过程的描述和桩与液压静力沉桩机的力学分析，确立了液压振动压桩在桩的强度条件下和液压静力沉桩机工作要求下的压桩频率与压桩力幅值之间的关系；定量分析振动压桩时系统的频率特性，得出了ZYB200B型液压静力沉桩机振动压桩时压桩频率的取值范围和系统能得到的最佳频率值。

For the first time, a screw pile and pile driver system for preventing flood and rushing to deal with an emergency was manufactured. The screw piles of the system is different from screw drills used to sap, and it doesn't push soils out. Analyses, including the screw pile's structural strength analysis and the screw blade's welding analysis, were done by ANSYS, which showed that the screw pile's structural strength is enough and that the distort of the screw blade is small. Testing on the screw pile and pile driver system showed that the system performed stably and could meet the need of preventing flood and rushing to deal with an emergency. A mechanics model of interaction of a screw pile and soil was built, and expressions of torque of screw pile's cylindrical part on the condition of screw pile's crew part being driven into soil fully were gained, then the relation of the torque with screw pitch and out diameter of cylinder, which shows the torque decreases with the screw pitch increasing, and that the torque increases with the out diameter of cylinder increasing, which was according with the experiments of the screw pile's being driven into soils, and thus a screw pile with the best structure was chosen. Experiments of bionic surface showed that, on the condition of certain pressure on the surface, the protruding bionic surface can not reduce adhesion and resistance and that the corrugated bionic surface can reduce adhesion and resistance. An orthogonal experiment of the corrugated bionic surface was done with the factors including the width of protrusion, the space between two protrusions, the trolley's velocity and the vertical surface pressure and with the surface frictional coefficient as the experimental target, and some inclusions were drawn that the best combination of the factors was acquired and that the width of protrusion affected the surface frictional coefficient remarkably.

研制了防汛抢险螺旋桩机系统，提高了沉桩作业效率；利用ANSYS对桩体进行整体结构强度分析以及螺旋叶片的焊接分析，表明桩体结构强度足够，焊接过程中，螺旋叶片的变形小；对整个螺旋桩机系统进行试验，表明该系统性能可靠，工作稳定，作业效率高，能够满足防汛抢险沉桩作业基本需要；建立了螺旋桩桩土作用力学模型，得出螺旋桩沉桩过程中螺旋桩螺旋部分完全进入土体时螺旋桩圆柱部分所受扭矩以及扭矩与防汛抢险螺旋桩的螺旋导程和圆柱外径的关系曲线，表明螺旋桩螺旋部分完全进入土体时螺旋桩圆柱部分所受扭矩随着螺旋导程的增大而减小，随着圆柱外径的增大而增大，这与螺旋桩沉桩试验结论相符合，据此优选出最佳结构的螺旋桩；仿生曲面试验表明，尺寸较小的球冠突起型仿生曲面在一定压力作用下未能起到减粘降阻的作用，而尺寸较大的波纹型仿生曲面相对平板具有一定的减粘降阻作用；以波纹型仿生曲面突起宽度、波纹型仿生曲面两突起之间间距、台车的牵引速度以及叶片表面垂直载荷为因素，以曲面摩擦系数试验指标进行正交试验，寻求出在一定试验条件下最佳因素水平组合；波纹型仿生曲面突起宽度在本试验条件下对曲面摩擦系数影响显著，而其它几个因素对曲面摩擦系数影响均不显著；通过波纹型仿生曲面突起宽度和台车牵引速度的单因素试验，表明曲面摩擦系数随着仿生曲面突起宽度的增大而减小，而随着台车牵引速度的变化基本保持不变，和正交试验结果保持一致。

In studies of interaction among pile, platform that above it and surrounding soil, this paper employ the concept of plate element to simulate the loading character of platform, and employ the concept of solid element to simulate the character of pile and soil, using the finite element method after understanding the geometry properties of pile, soil and the platform. Analyzing the loading properties of the three entities above and their deformation, this paper also employ a special element, Penalty Element. The introduction of penalty element of this kind has served to guarantee the join harmony of displacement between solid element and plate element, thereby effectively resolving the join problem between platforms, pile that support it and surrounding soil.Considering significant property difference between pile material and its surrounding soil, there may be much shear stress on their contact interface produced under vertical load, thus causing displacement or fission. Therefore it is necessary to adopt one special constitutive law of this kind of contact interface, which can reflect its feature of loading and deformation thoroughly. On the basis of the deformation feature and constitutive laws of some contact interface obtained by Zhang Dongji and people concerned through some single-shear experiments on contact interface between structure and soil, this paper employ one pile-soil three-dimensional constant thickness contact interface model to simulate the " slide" taken place on the interface between pile and its surrounding soil. With this kind model, this paper has also created one finite element model, which can be applied to perform finite element calculation and analyze the pile-loading feature, and deduced its element stiffness matrix.

在承台-桩-土共同作用中，考虑桩与承台的几何特性，采用有限元方法，用实体单元模拟桩土，用板单元模拟承台，更具体地分析桩和承台的受力特性和变形，而且还采用罚单元—既实体单元与板单元之间连接必须满足变形协调条件，来有效地解决了承台与桩土的连接问题，且在桩土共同作用中，由于桩体结构的材料性能与周围土层性质相差较大，在竖向荷载下有可能在其接触面上产生较大的剪应力从而导致错动或开裂，因此，为了充分反映桩土接触面上的受力及变形特征，应采用一种桩土接触面特有的本构关系，即利用张冬霁等人关于结构与土体接触面单剪试验所得到的接触面变形特征及其本构关系，引入桩-土三维等厚度接触单元来模拟桩与桩侧土之间的&滑移&，在此基础上建立可用于桩基承载性状分析的有限元计算单元模型，并推导出了各单元的刚度矩阵。

Experimental results show that: bearing capacity of JPP is thirty percent higher than that of cast-in-place pile which has the same length and diameter with JPP. The deformation of JPP is controlled by core pile; axial force distribution of PHC is different with soil-cement; and their axial force ratio in same section is their elastic modulus ratio. Distribution of inner and outer friction resistance is similar; and the inner friction is about 1.62 times of the outer one; it is about the ratio of JPP diameter and PHC diameter. Furthermore, the relation between friction resistance and relative displacement is similarly hyperbolic; and the relation between dip resistance and displacement is also hyperbolic.

试验结果表明，JPP桩与同桩长、同桩经灌注桩相比承载力高30%以上；JPP桩变形由芯桩控制，管桩轴力分布与水泥土轴力分布规律不一致，但同一截面上管桩和水泥土的轴力比值约为其弹性模量的比值；内外摩阻沿桩身的分布规律类似，内摩阻是外摩阻的1.62倍左右，约为JPP桩直径和管桩直径的比值；桩侧摩阻力与桩土相对位移近似双曲线分布，桩端阻力和桩端位移也近似双曲线分布。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。