Diagnostic Curve Methods for Consolidation Coefficient

Two new diagnostic curve methods, which do not require the implicit or explicit determination of initial or final dial gauge readings for primary settlement, are proposed for the identification of the consolidation coefficient. Besides the estimate of the consolidation coefficient, these methods also yield an estimate of the range of primary settlement. In these methods, the diagnostically plotted points are matched to the diagnostic curves with a parallel shift of axes to yield the estimates of the consolidation coefficient and range of primary settlement. The new methods do not require dial gauge readings up to 100% of primary consolidation and can also be used even when very scarce data are available. Using the proposed methods, a nonideal condition can also be identified.     

拐点计数法及其在材料科学中的应用

采用集合论的形式对一种体视学新方法,即拐点计数法及相应的体视学基本关系式进行了描述和推导,使之更加条统、准确和明瞭。并进而讨论了它们在材料科学中的各种可能应用及有关问题。     

Inflection Point of Development of Mining Industry in China is Approaching

The global economic recovery is slow the firs thalf of this year. The demand of energy suffered the most from the increasingly instability and uncertainty, and the external dependence of mining products in China continued to rise. At the same time, production of the main mining products still grew while the pace has slowed down. In brief, the development of mining industry in China was still at the stage of "mass and haste production".     

Identifying Consolidation Coefficient: Linear Excess Pore-Water Pressure

Diagnostic curve methods are developed for simultaneously identifying consolidation coefficient, final settlement, and ratio of top and bottom excess pore-water pressures from observed settlements, in the case of linear excess pore-water pressure. Simple equations are also proposed for estimating consolidation coefficient and final settlement. The proposed methods and equations are applicable for any type of linear loading or drainage condition (one-way or two-way drainage). Solutions for pore-water pressure distribution and transient settlement of clay layers under linear loading of pore-water pressure with one-way drainage are also developed, which are used in the development of the methods. The proposed methods do not require full settlement data for the identification of parameters and the parameters can be identified from only initial but adequate settlement data.     

Determination of the Solute Diffusion Coefficient by the Droplet Migration Method

Further analysis of droplet migration in a temperature gradient field indicates that different terms can be used to evaluate the solute diffusion coefficient in liquid (D _L ) and that there exists a characteristic curve that can describe the motion of all the droplets for a given composition and temperature gradient. Critical experiments are subsequently conducted in succinonitrile (SCN)-salol and SCN-camphor transparent alloys in order to observe dynamic migration processes of a number of droplets. The derived diffusion coefficients from different terms are the same within experimental error. For SCN-salol alloys, D _L = (0.69 ± 0.05) × 10⁻³ mm²/s, and for SCN-camphor alloys, D _L = (0.24 ± 0.02) × 10⁻³ mm²/s. This article is based on a presentation made in the symposium entitled “Solidification Modeling and Microstructure Formation: In Honor of Professor John Hunt,” which occurred March 13-15, 2006, during the TMS Spring Meeting in San Antonio, Texas, under the auspices of the TMS Materials Processing and Manufacturing Division, Solidification Committee.     

Simplified Method for Consolidation Rate of Stone Column Reinforced Foundations

Field observations and numerical studies demonstrated that stone columns could accelerate the rate of consolidation of soft clays. A simplified method for computing the rate of consolidation is presented in this paper by assuming that stone columns; (1) are free draining; (2) have higher drained elastic modulus than soft clay; and (3) are deformed 1D. The formats of the final solutions in vertical and radial flows are similar to those of the Terzaghi 1D solution and the Barron solution for drain wells in fine-grained soils, respectively. Modified coefficients of consolidation are introduced to account for effects of the stone column-soil modular ratio. The new solutions demonstrate stress transfer from the soil to stone columns and dissipation of excess pore water pressures due to drainage and vertical stress reduction during the consolidation. Comparisons between the results from this simplified method and the numerical study by Balaam and Booker in 1981 exhibit reasonable agreement, when the stress concentration ratio is in the practical range (2–6). The discrepancies in the results from these two methods are discussed. This paper also includes design charts and a design example.     

刚塑性有限元求解板材轧制过程的奇异点问题

轧制过程奇异点的存在使得求解不易收敛,是有限元求解轧制过程问题的难点之一。提出了采用双速度点模型解决第一类奇异点问题和相对滑动速度抛物线模型解决第二类奇异点问题。以某钢厂实际轧制数据为例,分析比较了奇异点处理方法对速度场以及计算时间和迭代次数的影响。当单元数从200增加到2 000时,采用双速度点模型处理第一类奇异点问题时计算时间和迭代收敛步数减少8%～67%,采用相对滑动速度抛物线模型处理第二类奇异点问题时计算时间和迭代步数减少15%～61%。双速度模型和抛物线模型处理奇异点方法加快了计算速度并改善了求解的收敛性。     

Aluminum Expansion Approaches The Inflection Point,With The Core Of A New Round Of Overcapacity Cutting As Self-Built Power Plants

<正>Shandong Development and Reform Commission recently announced in a documen that based on the enterprise self-inspection and provincial inspection results,it had ordered Shandong Weiqiao Pioneering Group and Xinfa Group to close 3.21 million tons o illegal aluminum production capacity by the end of July.Besides Shandong,other provinces and regions with high aluminum production     

Equal Strain Consolidation by Vertical Drains

This paper shows the development of a series of closed-form solutions of equal strain consolidation in the presence of a vertical drain with smear and well resistance. Using an approach that considers the effects of both the radial and vertical drainage in a fully coupled fashion, solutions are obtained for the excess pore pressure and the degree of consolidation in the compressible soil subjected to a step- or ramp-loading situation. The closed-form solutions in the present paper may be evaluated in an electronic spreadsheet on a standard personal computer.     

系数传递法在某边坡稳定性计算中的应用

滑坡是现阶段工程建设过程中经常遇到的地质灾害现象,预见边坡的稳定性变得尤为重要,本文采用系数传递法对谷坡的工程稳定性进行了计算分析,从而达到预见边坡稳定性的目的.     

Model for Large Strain Consolidation by Centrifuge

A numerical model, called CC1, is presented for one-dimensional large strain consolidation in a geotechnical centrifuge. The model includes all the capabilities of a previous large strain consolidation code, CS2, written for surcharge loading under normal gravity conditions. In addition, CC1 accounts for variation of acceleration factor N over the depth of a centrifuge test specimen. The development of CC1 is first presented, followed by a comparison of simulated time–settlement curves with experimental measurements for Singapore marine clay and a parametric study illustrating the effects of nonuniform N distribution on centrifuge consolidation behavior. Simulations indicate that the effect of spatially varying N is most strongly controlled by the ratio of specimen height to centrifuge arm length and that the error associated with the assumption of constant N is relatively small if this ratio is 0.2 or less. Finally, CC1 is used to calculate the optimal location within a centrifuge specimen of Singapore marine clay at which to match the desired N value and the error that results if N is matched at the initial midheight of the specimen.     

影响系数法在现场动平衡中的应用

转子质量不平衡是造成转动设备振动的主要原因之一。随着测相技术的发展,利用影响系数法进行在线动平衡技术得到了越来越广泛的应用。通过在包钢热电厂6#鼓风机中的实际应用,论述了影响系数法与传统的转子平衡技术相比的优越性,并对影响系数法中起重要作用的试加重量和试加位置进行了探讨。     

用截交线法判定轧件咬入点

确定型钢轧制轧件的咬入点对实现稳定轧制有重要意义。基于对轧件与轧辊截交线的分析，提出了在二维直角坐标系中确定轧件咬入接触点的方法。     

Vertical and Radial Consolidation Analysis of Multilayered Soil Using the Spectral Method

A new, easy to implement, solution to the consolidation of multilayered soil based on the spectral method is presented. Combined vertical and radial drainage under instantaneous or single ramp loading is considered, ignoring well resistance. Flow in the vertical direction is based on the average hydraulic gradient at a particular depth which allows smear effects to be included. The excess pore-water pressure profile across all soil layers is described by a single expression calculated with common matrix operations. Average excess pore pressures within or across any number of layers are easily calculated from the single expression. The new model is verified against other solutions from the current literature indicating that the more general spectral method model can replace the separate solutions developed for specific problems.     

高水固结充填采矿法工艺创新与应用

山东玲珑金矿灵山分矿在应用高水固结全尾砂充填采矿法时,根据矿体的不同赋存条件,应用了技术上可行、经济上合理、安全可靠的采矿工艺,解决了不稳固矿体回采中存在的一系列技术难题,在控制采幅、抑制地压活动、充填支护、降低贫化和损失等方面都取得了良好效果,获得了较好的经济效益.     

型钢孔型设计中若干特殊点的确定方法

确定型钢孔型各线段的切点或交点对孔型分析及线切割程序有重要意义。基于在解析几何的基础上确定了切线和交点的唯一性。该方法求解简单、实用、可靠。     

整流柜均流系数测算方法的改进

传统的整流柜均流系数测算需要工作人员在正常运行或电流升高的整流柜上测量快熔两端的毫伏压降,这对测试人员和整流柜来说都存在较高的危险。使用红外线测温仪可以随时检查每条桥臂上整流元件和快熔的运行情况,套用计算均流系数的公式可以计算桥臂的温度系数,跟踪桥臂的均流变化情况,比传统的方法更安全、简便。     

一种基于互相关函数的小波系数相关阈值去噪方法

针对传统的小波系数相关去噪方法中,在对含噪信号进行小波变换后,各尺度上的小波系数会产生微小偏移的问题,提出了一种基于互相关函数的小波系数相关去噪方法.采用互相关算法,计算各个尺度与原始含噪信号产生的偏移量,再把偏移后的尺度进行相关分析,得出准确的突变信号;为了去除信号突变附近附带的少量噪声信号,再采用临界阈值去噪方法对相关分析后的尺度信号进行阈值处理,最后经过信号重构可以得到精确的有用信号.