Finite Difference "m-k" Method of Calculation of Anchor-stabilizing Piles

Based on the principle of the foundation coefficient " m-k " method,the ginite difference method is presented to analyze the internal forces of a whole prestressed anchor stabilizing pile. The calculation and figure treatments are programmed. An example shows that the high precise solution can be obtained if the segments are small enough, though more computing time may be consumed. Obviously,the calculation precision is better than that of traditional method. The results of figure treatments by the program can optimize the construction design of stabilizing piles. Three kinds of support condition are taken into account.The foundation coefficient "m-k " method applies to the situation that above the slide-surface is soil layer or efflorescence layer,while below the slide-surface is terrane.     

Impact Analysis on Design Parameters about Service Behavior ofCantilever Anti slide Piles

Directing toward the flow design of cantilever anti slide piles, the thesis which is based on foundation coefficient method and finite element method mainly analyzes service behavior influences by changing several design parameters, such as cross section     

Dynamic Response Analysis of High-rise Pile Cap-soil-structure under the Wave and Earthquake Action

Finite element software was used to simulate the internal force and deformation of high-rise pile cap-soil-structure under the wave and earthquake action. Meanwhile, wave force was calculated by using Morison equation, and the mechanical behavior of structure was simulated by inputing horizontal El-Centro wave. Then, the initial state and the state of the largest positive and negative acceleration were selected to study the structure according to the time history curve, and the displacement, bending moment, shear and axial force changes of pile foundation under wave and earthquake action were discussed, which was compared and analyzed with the structural response under the action of earthquakes solely. The result shows that the moment of front row of piles is biggest, and the force of pile bolck is the most dangerous; the axial force of the corner piles is the largest, and one of the center piles is the smallest under the action of wave and earthquake. When the wave forces and seismic forces are in the same direction, the displacement, moment, and shear force of pile bolck will be increased, on the contrary, the displacement, moment, and shear force of pile bolck will be decreased.     

Model Investigation of Sliding Resistence Mechanism for h type Anti slide Pile

In order to improve the understanding of the mechanism of h type anti slide pile to reinforce the slope, this type of anti slide pile with different anchorage depth and distance between fore pile and back pile was investigated through model test by specially designed experimental apparatus. The test results indicate that the distribution of resistence and thrust acting on fore pile is triangular, and the resistence acting on back pile is rectangular. For the landslide thrust acting on back pile, there are three types of distribution: parabolic, parabolic with upper center of gravity and rectangular. Therefore, when the calculation pattern for the part of h type pile above the potential slip surface is defined, the distribution of resistence and thrust acting on fore pile can be fixed as triangular, and the resistence acting on back pile can be fixed as rectangular. Whilst the distribution of landslide thrust acting on back pile should consider the influence of property of soil, anchorage depth and the distance between fore pile and back pile. Some conclusions drawn from this test can provide useful reference for the design of h type anti slide pile.     

Damping Force of Electro-rheological Damper

There are three working modes of electro rheological(ER) damper, flow mode of fixed electrode, shear mode of slide electrode, mixer mode of slide electrode. The damping force is analyzed for gas-filled ER damper of flow mode of fixed electrode. There are three sections of damping force, and they are background damping force of a fluid viscosity, electric damping force of applied electric field and pressure of gas. The characteristic of ER damper is adjustable by electric filed strength for electric damping force. At the same time, some structure factors of ER damper are discussed.     

Study on CAD System of Slope Pile-Anchor Retaining Structure

The process of designing the common slope pile-anchor retaining structure in Chongqing is analyzed, the finite element method is applied to calculate the force of the structure and design the anchor bar, pile and holding sheet. The CAD system is developed including fore-process, post-process, calculation of the structure and drawing by computer in order to make the designing of slope pile-anchor retaining structure more quickly, more economical and convenient. It has been applied in practice of the slope engineering with a good result.     

Analysis of Wave Loads on the Grouping PileFoundation with Slab Merged in Water

In order to get the wave loads on pile groups with slab merged in water, an engineering approach was proposed. Three coefficients in terms of slab effect were discussed and a time -domain analysis of wave forces acting on piles was conducted. Wave diffraction from a slab was obtained by the potential theory and eigenfunction expansion method, while wave loads on piles were evaluated by Morison formula. The wave force on pile obtained by the proposed method and the numerical simulation are in good agreement, which shows a good reliability of the proposed method. The result shows that, owing to the size of slabs, there exist some differences in the changing rule of slab effect varying with the submerged depth. The resultant force decreases with the rise of incident wave number, and the changing trend of its acting point appears an inflection point at some wave number. The minimum force acting on piles lies in the meeting-wave side of the slab, while the maximum one arises at the back side or in the scope of 30 degrees between the axis of slab, which is perpendicular to the incident wave, and the back side. The presence of slab causes the deflexion and phase difference of inline force. Meanwhile, the grouping piles coefficient can be taken as 0.7.     

Effective Unloading Area between Cantilever Piles

The formation mechanism of the arching effect between cantilever piles is studied according to their stress characteristics. The soil arch is classified into three types based on its position in a space coordinate system, namely, a horizontal arch, a vertical arch and a free face arch. The master factor for distribution of unloading area between piles is the horizontal arch effect. The range of effective unloading area is defined. Based on the failure pattern of soil arches and the relationship between soil strength theory and the static equilibrium principle of soil arches, a calculation model is established by considering the presence of geostatic stress and sliding thrust force. The relation between soil strength and critical height is studied by variation of cohesion and friction angle. In addition, the impact of canonical distributions of the earth pressure to the vector height of unloading area is also discussed. Finally, the calculation model is verified by an example from real engineering work.     

荞麦大垄双行高产栽培技术

科学技术是第一生产力。随着科学技术的发展,传统栽培技术与现代栽培技术相互融合在一起。本文是通过对多年多点试验研究结果的总结和集成,改变过去荞麦传统种植栽培为大垄双行栽培种植。该栽培技术从播前准备、选地、整地、合理施肥、种子处理、播种、田间管理、病虫害防治、机械化收获、包装、运输及贮藏进行了详细说明。     

Foundation pile test by self-balanced method of rock-socketed piles and friction piles in multilayer soil geological structure

结合检测工况对测试数据的影响,对自平衡“精确转换法”进行改进,提出摩擦桩位移协调转换法和嵌岩桩的荷载协调转换法,实际应用结果说明两种转换方法合理。所得测试结果表明湄公河大桥桩基承载力符合设计要求;分析湄公河大桥试桩的侧摩阻力和端承力分布,嵌岩桩和摩擦桩纵向承载均以侧阻力为主。     

Comparative Analysis of Heat Exchange Performance ofEnergy Piles and Borehole Heat Exchangers in GSHP System

Due to their enhanced cost-effectiveness and efficiency over traditional borehole exchangers, energy piles are increasingly used in Ground Sourced Heat Pump (GSHP) projects. In this paper, the structural characteristics of these two types of heat exchangers and their heat transfer mechanism were discussed firstly. The thermal response tests (TRT) were performed on two testing energy piles in one GSHP project in Nanjing, China. The TRT results were then used to verify the numerical simulations, which suggests that the heat exchange performance of energy piles is superior to that of the traditional borehole exchangers. Meanwhile, the numerical simulation method used in this paper was considered applicable to the optimization design of ground heat exchangers in GSHP system.     

Application of Fundamental Formula for Matrix Function in Solution of Circuit Transient Respond

In this paper, the fundamental formula of matrix function is discussed. The author puts forward a new method of solution of two-rank linear transient respond, using the fundamental formula of matrix function. The method can be spread and applied to solution process of high rank linear circuit transient respond and is superior to that of traditional solution.     

Parameter Analysis of Effects of Axial Load on the Lateral Response of Piles

Based on the small deformation assumption, the equations of the laterally loaded piles influenced by the axial load were established. The effect of axial load on the lateral response of piles was studied with parameter analysis. The analysis shows that internal force and deformation of laterally loaded pile under axial loading is actually closely linked with the values of axial and lateral loads. In general, the high level axial load should be focused on. It is more significant that the effect of axial load on the internal force and lateral deflection of the upper part of flexible piles, while there is little effect on deep of long-thin pile foundation. The effect of axial load on the lateral response of pile is the largest as coefficient form of subgrade reaction increases linearly, while the effect is minimal as coefficient form of subgrade reaction is a constant. Except in case of buckling, the changes of axial load along the pile direction have little influence on the magnitudes of deflection and moment. The assumption that the axial load is constant with depth can meet the requirements of engineering.     

Mechanism Kinematic Chain Isomorphism with All-Loop-Link-Join-Martrix

Based on. generalized topological figures of kinematical chains, all-loop-link-join-matrix is built, which contains all information of kinematical chains. The constructive principle and method of that matrix is put forward. It is applied in the research of the Isomorphism Identification of kinematical chains. The method and the main process of the Isomorphism Identification of kinematical chains is given out further. Some practical examples are solved by the new method. The matrix contains all loops of kinematical chains, and solves forky problems in the choice of loops. It cannot be constrained by the bars and the freedom of kinematical chains. In the matrix, elements are fewer; the amount of calculation is little, and the speed of calculation is high, so the method can be realized in computer. Because of the use in computer, the method is efficient and reliable. The method is certified by tremendous examples, especially in the Isomorphism Identification of kinematical chains which contain many bars and loops.     

Numerical Analysis on Mechanism of the Metal Pushing Type Continuously Variable Transmission

Continuously variable transmissions have attracted a great deal of interest in recent years because they shift with very little shock and offer significant advantages of acceleration performance and fuel economy for automobile.The slide angle is very important physical parameter in belt study. It's magnitude expresses the changing of direction of friction force's and makes the distribution of force very complicated. In this paper,the reason of the slide angle has been discussed. The formulae of wrapping angle relation with slide angle is put forward. The magnitude of slide angle is computed by used the Runge Kutta method in different speed ratios. On the basis of study a new descrete numerical analyse approach is proposed to analysis and calculate the tension and thrust of the key work piece's the metal rings and the metal blocks of the metal pushing type continuously variable transmission respectively under different speed ratios and torque ratios. The research result in this paper can be used to analyse the strength of the metal rings and the metal blocks and improve the load capability of the CVT gearbox. [WT5HZ]     

Anti sliding pile performance under acid stress coupling

Anti sliding piles are an important engineering structure used extensively in landslide prevention. Their durability influences their work lives. In a laboratory model experiment of a cantilevered anti sliding pile under acid stress coupling, the pile body displacement variation is monitored continuously, and both concrete strength and neutralization depth are tested. The results indicate that the concrete strength decreases gradually under acid stress coupling, while the displacement increases continuously. The neutralization depth of the concrete in the anti sliding pile is linear to the square of duration in acid stress coupling.     

Lateral Load Capacity Analysis of Variable Section Hybrid Piles with Wteel Casing

With the construction of deep-water bridge foundation, steel casing is left after the construction of cast-in place piles due to the dismantle difficulty. Then the pile actually forms a variable section pile which has bigger section area at upper part. Using the nonlinear NL method, the displacement and the internal force are analyzed for piles with and without casing in Sutong Bridge. It is found that the displacement of pile with casing can be reduced by 50%, and it can not be ignored for accurate calculation of displacement. 8 model pile tests are carried out, which suggests that the slurry thickness can significantly affect the capability of co-working between the pile and the casing.     

Adaptive Image Segmentation Method Based on Ncut

In order to solve the problem that requires some factors by manual in the traditional Ncut algorithm, limit the generality of the algorithm, an adaptive image segmentation method is proposed by improving the traditional Ncut algorithm. First, instead of the two control parameters on the calculation of weight matrix that influence the segmentation results in the traditional Ncut algorithm by groups of potential theory; then in order to reduce the sensitive to the number of the cluster and the center of the cluster in the K-means algorithm, calculate on the eigenvector of the Ncut algorithm by the minimum spanning tree, to get the final number of cluster and the center, and then uses the K-means clustering algorithm to get the final segmentation result. The experimental results show that the proposed method not only improves the versatility of the algorithm, and the segmentation is good.     

Inter‐row Mulch Increase the Water Use Efficiency of Furrow‐Irrigated Maize in an Arid Environment

The effect inter‐row polyethylene mulch on the water use efficiency and crop productivity of furrow‐ and drip‐irrigated maize (Zea mays L.) was evaluated in a field study. In contrast to the traditional ‘on ridge’ mulching, the inter‐row polyethylene mulch was placed in such a way that it could be easily removed for reuse since the row of plants itself was not covered but the furrows were completely covered. Irrigation needs were computed by multiplying the cumulative Class A Pan evaporation between irrigations by a crop coefficient that changed through the growing season. Our results indicate that inter‐row mulching induced earliness under both irrigation treatments. Seventy five percent of canopy density was attained in the mulched treatments contrasting with 45–61 % in the non‐mulched treatments at 34 days after sowing. Throughout the growing period, shoot biomass was significantly higher for the mulched treatments that had as well higher root biomasses. The overall estimated evaporative losses from the non‐mulched treatments were between 37 % and 39 % of the total water applied. The whole gross canopy water use efficiency in the furrow and drip mulched treatments was 64 % and 45 % higher than in the respective non‐mulched treatments. These results indicate that inter‐row polyethylene mulch is an efficient technique by which soil evaporation is reduced and plant productivity increased.     

复合土钉支护转角有利影响范围

基坑复合土钉墙转角处有明显的空间效应,受力变形较小,对支护结构有利,但不清楚转角定量的有利影响范围,目前设计中仍按照与基坑中部一样保守设计,为在此范围内降低土钉用量,避免保守设计,对水泥土搅拌桩复合土钉支护结构建立了全尺寸整体三维有限元模型,这种模型包含基坑的转角,能考虑基坑的空间效应,通过建立接触面单元,能考虑土体和搅拌桩、土体和土钉的相互作用,量化分析了基坑转角对支护结构受力和变形的有利影响范围,计算结果表明,基坑转角对开挖面水平位移、地表沉降、坑底隆起、土钉轴力的有利影响范围分别约为1.3、1、1、1.2倍的开挖深度。经与实际工程现场实测值对比,验证了该模型分析结果的可靠性,同时分析结果优于平面二维和局部三维有限元模型,结论为复合土钉支护结构的优化设计和安全施工提供了理论依据和研究方法。