Probabilistic seismic stability of three-dimensional slopes by pseudo-dynamic approach

Probabilistic analysis is a rational approach for engineering design because it provides more insight than traditional deterministic analysis. Probabilistic evaluation on seismic stability of three dimensional (3D) slopes is studied in this paper. The slope safety factor is computed by combining the kinematic approach of limit analysis using a three-dimensional rotational failure mechanism with the pseudo-dynamic approach. The variability of input parameters, including six pseudo-dynamic parameters and two soil shear strength parameters, are taken into account by means of Monte-Carlo Simulations (MCS) method. The influences of pseudo-dynamic input variables on the computed failure probabilities are investigated and discussed. It is shown that the obtained failure probabilities increase with the pseudo-dynamic input variables and the pseudo-dynamic approach gives more conservative failure probability estimates compared with the pseudo-static approach.

Minimum Amount of Slop Cut in Batch Distillation

The pulse-control operation technique which alternates between total reflux operation and total efflux operation in batch distillation was studied along with the minimum amount of slop cut. Total reflux time was confirmed by dynamic simulation, and total efflux time was adopted by statistic method. For the mixture of hexane and cyclohexane and the traditional constant reflux ratio operation strategy, the amount of slop cut is 1.8-2.1 times of the minimum amount of slop cut; whereas for the pulse-control operation strategy, it is 1. 2 -1.4 times of the minimum amount of slop cut. So compared with the traditional constant reflux ratio operation, the pulse-control operation can decrease the amount of slop cut and operation time, and meanwhile, enhance separation efficiency and yield.

The Operation of Draining Column Holdup for Slop Cut Withdrawal in Batch Distillation

The new mode of operation for slop cut withdrawal in batch distillation, i.e., draining Column liquid holdup at the end of slop cut period, was proposed. And the stopping criterion for the operation was investigated, Experiments were carded out with isopropanol-n-propanol binary system and isopropanol-n-propanol-n-butanol ternary system in a distillation column with a liquid collector installed between the reboiler and the column section, Experimental results in a Ф 45mm batch column show that the proposed policy can overcome the flywheel effect caused by column liquid holdup and thus cut down operation time and energy consumption 31%-61%.

Centrifuge and numerical modeling of h-type anti-slide pile reinforced soil-rock mixture slope

Due to the loose structure,high porosity and high permeability of soil-rock mixture slope,the slope is unstable and may cause huge economic losses and casualties.The h-type anti-slide pile is regarded as an effective means to prevent the instability of soilrock mixture slope.In this paper,a centrifuge model test was conducted to investigate the stress distribution of the h-type anti-slide pile and the evolution process of soil arching during the loading.A numerical simulation model was built based on the similar relationship between the centrifuge model and the prototype to investigate the influence factors of the pile spacing,anchored depth,and crossbeam stiffness,and some recommendations were proposed for its application.The results show that the bending moment distribution of the rear pile exhibits Wshaped,while for the front pile,its distribution resembles V-shaped.The soil arching evolution process during loading is gradually dissipated from bottom to top and from far to near.During the loading,the change of bending moment can be divided into three stages,namely,the stabilization stage,the slow growth stage,and the rapid growth stage.In engineering projects,the recommended values of the pile spacing,anchored depth,and crossbeam stiffness are 4.0d,2.0d,and 2.0EI,where d and EI are the diameter and bending stiffness of the h-type anti-slide pile respectively.

油船slop舱中油水混合物的分离速度模型

通过分析油船洗舱水中油水重力分离的物理过程 ,建立油滴上浮过程中碰撞聚合后的速度模型 。

The Operation of Draining Column Holdup for Slop Cut Withdrawal in Batch Distillation

The new mode of operation for slop cut withdrawal in batch distillation, i.e., draining column liquid holdup at the end of slop cut period, was proposed. And the stopping criterion for the operation was investigated. Experiments were carried out with isopropanol-n-propanol binary system and isopropanol-n-propanol-n-butanol ternary system in a distillation column with a liquid collector installed between the reboiler and the column section. Experimental results in a 45mm batch column show that the proposed policy can overcome the flywheel effect caused by column liquid holdup and thus cut down operation time and energy consumption 31%—61%.

A Study on the Estimation of Ship Waves Interaction with the Sloping Banks of the Channel

The problem of shore wash in environmental engineering is connected in particular with the effect of waves generated by the ships and fast speed boats. Another problem is protection of ＂Marines＂ with anchored boat against waves. Sloping banks provoke unfavorable transformation of waves. Simultaneously sloping bank is the factor which significantly complicates prediction of wave pattern in numerical analysis. The purpose of present paper is to demonstrate the results of numerical investigation of ship waves pattern in constrain water area with slope banks by panel method for non-linear ship waves calculation usually applied for ship hull perfection as routine instrument of towing tanks technology. The method initially developed for calculation of ship hull waves in inviscid infinite fluid was adapted to meet boundary conditions on slope banks. Verification of the method was done for 60-series ship in rectangular channel. Development of wave pattern generated by two ship of different types--monohull ferries and river catamaran was investigated. It was found that ship waves height significantly increased due to slopping banks comparing with case of deep water and shallow water rectangular channel.

The establishment of 3D visualization modeling for the jointed slope

The 3D visualization model of slop with structural plane can displayed the characters of structural plane in slop directly, and illustrated the spatial combination. It is a modem and critical question in the field of geotechnical engineering. Based on the peculiarity of the reconnaissance and the research of the visualization by formers, systemized the method fit for building 3D visualization model of slop with structural plane. Write the special program with Visual C^-＋ computer language and illustrated it by OpenGL, the program can displayed and captured the random section plane. The program has a satisfied result by proving with the real projects.

ABRUPT DEFLECTED SUPERCRITICAL WATER FLOW IN SLOPED CHANNELS

The effect of the bottom slope on abrupt deflected supercritical water flow was experimentally and theoretically studied. Model tests were conducted in a flume of 1.2 m wide and 2.6 m long with sloped bottom at an angle 35.54°, its length of deflector was 0.2 m and the deflection angles were 15° and 30°. An approximate method for calculating the shock wave angle and depth ratio of the abrupt deflected supercritical water flow was suggested, and a correction coefficient for the hydrodynamic pressure was introduced to generalize the momentum equation in the direction perpendicular to the shock front. It must be noticed that in the sloped channel the shock wave angle and the depth ratio are no longer constant as those in the horizontal channels, but slowly change along the shock front. The calculated results are in good agreement with measured data.

THE SLOP FLUX METHOD FOR NUMERICAL BALANCE IN USING ROE'S APPROXIMATE RIEMANN SOLVER

Imbalance arises when the Roe＇s method is directly applied in the shallow water simulation.The reasons are different for the continuity equation and the momentum equations.Based on the Roe＇s method,a partial surface method is proposed for a perfect balance for the continuity equation.In order to generate a mathematically hyperbolic formulation,the momentum equations are split,which causes incompatibility in the calculation of the momentum equations.In this article a numerical approach named the Slop Flux Method（SFM）is proposed to balance the source terms and the flux gradient based on the finite volume method.The method is first applied to shallow water equations.The model is verified by analytical results of classical test cases with good agreement.Finally the method is applied to a steady flow simulation over a practical complicated topography and the result shows good balance and conservation.

基于斜坡单元和语义分割的皖南地区滑坡灾害易发性评估

滑坡灾害严重影响着人们的生命和财产安全,对自然环境造成重大破坏。以斜坡单元为单位进行滑坡易发性评估能够更加接近真实的滑坡地形,为滑坡灾害的防治提供更加科学的理论支持。本文以安徽省皖南地区为研究区,基于黄山、宣城、池州市滑坡点数据以及皖南地区基础地理数据,利用主成分分析和多重共线性分析方法筛选滑坡评价因子,提出将斜坡单元几何形状信息和语义分割方法相结合的创新方法,构建滑坡灾害易发性评估模型,对皖南地区的滑坡灾害易发性进行评估,揭示其空间分布规律。结果表明:结合斜坡单元和语义分割方法构建的滑坡易发性评估模型具有较高的预测精度,能够充分考虑斜坡单元的几何形状信息对滑坡易发性的影响,较为准确地评估皖南地区的滑坡易发性。评估结果符合滑坡形成机理,其中62.19%的滑坡单元分布在滑坡易发性等级中—高的斜坡单元上,模型预测AUC值为0.878,与缺少几何形状信息的CNN模型进行对比,预测精度明显提高。

海昏汉简《诗经》研究三题

学术界广泛认可海昏汉简《诗经》为《鲁诗》。从已经公布的部分文本内容来看,海昏汉简《诗经》符合“故”的文本特征,因此,疑为《汉书·艺文志》著录的《鲁故》。海昏汉简《诗经》目录简的编连,应符合古书正文在小题前而小题又在大题前的通例,标题简应当置于末尾而不当在前。据海昏汉简《诗经》目录简中“予其惩而八”可知,《周颂·小些》“予其惩而些后患”当断句为“予其惩而,些后患”,与《毛诗》同。

生物炭施加垄沟集雨种植对水土流失及紫花苜蓿草产量的影响

为缓解我国黄土高原区干旱胁迫和控制水土流失,本研究采用裂区设计,生物炭施加模式(生物炭施加和无生物炭施加)为主区,耕作模式(打结垄、开敞垄和平作)为副区,研究不同生物炭施加模式和耕作模式对土壤水分、径流、泥沙流失、养分流失、紫花苜蓿(Medicago sativa L.)干草产量和水分利用效率的影响。试验结果表明,在2019和2020年紫花苜蓿生育期,与平作处理相比,开敞垄和打结垄处理的径流量、泥沙、全氮、全磷、有机质流失量分别减少20.1%~37.7%和60.1%~64.7%,54%~75.5%和77.1%~87.6%,44.4%~65.5%和49.0%~81.8%,36.7%~75.3%和48.6%~87.3%,48.2%~72.9%和58.6%~85.4%,土壤贮水量、紫花苜蓿干草产量和水分利用效率分别增加39.5~52.1和31.2~60.5 mm,26.2%~31.7%和26.5%~35.2%,10.07~14.86和12.14~16.55 kg·hm^(-2)·mm^(-1)。与无生物炭施加处理相比,生物炭施加处理的径流量、泥沙、全氮、全磷和有机质流失量分别减少48%~69%,94%~125%,12%~24%,28%~46%和35%~48%,土壤贮水量、紫花苜蓿干草产量和水分利用效率分别增加42.93~26.09 mm,106%~111%和1.96~6.90 kg·hm^(-2)·mm^(-1)。本研究表明,生物炭施加打结垄沟集雨种植是该区域适宜耕作模式。

风化残积砂土相对密实度及含水率对抗剪强度的影响

全风化花岗岩回填土的抗剪强度受其含水率与相对密实度的影响。优化回填土含水率与相对密实度来提高土体抗剪强度是实现中缅油气管道龙陵段管道作业边坡坡面侵蚀治理的手段之一。以管沟回填的全风化花岗岩回填土为研究对象,通过室内直剪试验和人工降雨模型试验,研究该类土体抗剪强度参数随着含水率和干密度的变化规律以及其抗冲刷能力。结果显示:1)干密度为1.30 g/cm^(3)的土样的最佳含水率为15%,此时其黏聚力和内摩擦角分别为20.33 kPa和34.59°,当土体含水率增加至25%时,其黏聚力降低至3.63 kPa,内摩擦角减小到32.42°;2)通过击实方式将土体的相对密实度从0.06提高至0.83,土体的黏聚力和内摩擦角分别提高53%和18%,相对密实度为0.50时,对土体抗剪强度参数的改善效果最佳;3)人工模拟降雨实验结果显示,坡面侵蚀模数与土体的抗剪强度有关,尤其与内聚力呈负相关关系。综上,相同含水率条件下,提高土体的相对密实度,能有效改善土体的抗侵蚀能力。

某高速公路滑坡的数值模拟及后缘坡体稳定性分析

通过对诸永高速公路台州段1^#滑坡（K120＋085～K120＋169）工程地质特征的分析，指出沿线区存在很多因修建公路引发的工程滑坡问题，然后采用边坡稳定性FLAC／Slope分析软件，对滑坡滑动前、后工况下稳定性进行数值模拟，并对滑移后的后缘坡体稳定性进行了数值分析。剪应变率云图和稳定性分析结果表明，滑动后的后缘坡体仍处于不稳定状态，又形成了新的滑坡体。

兰尖铁矿深凹露天矿山高陡边坡稳定性分析

为了研究外界因素对结构面控制型边坡稳定性的影响,以兰尖铁矿营盘山段边坡为工程背景,采用Geo-Slop软件,分别分析了该边坡在地下水、地震载荷以及地下水和地震载荷共同作用下的边坡稳定性,结果表明:地下水对边坡稳定性影响较小,安全系数的变化范围在0.015～0.030;地震载荷对边坡稳定性的影响较大,安全系数的变化范围在0.125～0.165;在地下水和地震载荷共同作用时,整个边坡处于临稳状态。

基于强度折减法下不同失稳判据对边坡稳定性的影响

为了充分了解不同失稳判据准则下强度折减法对分析边坡稳定性的影响,解决有关边坡失稳的问题,利用ABAQUS有限元软件平台开展了不同失稳判据准则下有限元强度折减法对分析均质土坡稳定性影响的研究。详细分析了在不同失稳判断准则下,利用强度折减法所得到的边坡安全系数之间存在差异性;并对不同失稳判据下土体强度参数的变化将对边坡稳定性所产生的影响进行了分析。研究结果显示:不同的失稳判据下利用强度折减法所得的安全系数之间存在一定的差异性,但其影响程度由土体强度参数在一定范围内的变化所决定;与此同时,土体粘聚力、内摩擦角和泊松比等参数的变化对于边坡临界状态时内部的塑性区的发展和滑动面的形状还存在一定的影响。

隐伏式缓倾顺层边坡滑移弯曲破坏机制及影响因素研究

针对隐伏式缓倾顺层边坡在降雨条件下易发生滑移弯曲破坏的问题,运用静力学分析法和能量分析法,在地质概化模型基础上建立了岩层发生滑移弯曲破坏的弯曲破坏段长度和临界坡长计算公式,以朱雀洞滑坡为算例对弯曲破坏段长度方程的合理性进行了验证,并对此类隐伏式缓倾顺层边坡发生滑移弯曲破坏的影响因素进行了分析。结果表明:层间内摩擦角、岩层倾角对弯曲段长度影响最大,地下水沿层间上升长度、岩层厚度、坡长、层间黏聚力和岩体综合弹性模量影响较小;对于给定的隐伏式缓倾顺层边坡,地下水在坡体内的空间关系是隐伏式缓倾顺层边坡产生滑移弯曲破坏的重要外在因素。同时,对隐伏式缓倾顺层软质岩边坡岩体抗弯刚度的取值进行了讨论,引入岩体弹性模量调整系数,并给出了相应的计算公式。

基于S-SAR技术的降雨-爆破耦合作用下高陡边坡变形特征研究

对于苏海图露天矿北帮高陡边坡,分析了降雨-爆破震动耦合作用对边坡稳定性的影响机理,利用S-SAR边坡雷达监测技术,实时监测分析降雨-爆破震动作用下边坡变形数据。结果表明在强降雨季,边坡稳定性较差。当降雨-爆破震动同时作用时,边坡表面变形呈现波动上升趋势,较雨季期间,单一降雨作用对边坡稳定性影响较大,是滑坡灾害的重点发生时间段。研究结果可为降雨-爆破耦合作用下的高陡边坡稳定性研究及进一步推动边坡雷达监测技术在露天矿山工程中的应用提供一定参考。

炼油厂污油净化处理及资源化回收的研究进展

本文介绍了炼油厂污油的来源、组成、性质及处理难点,综述了炼油厂污油的净化处理技术,包括离心分离处理技术、超声波处理技术、微波处理技术、膜分离处理技术及热沉降处理技术等,分析了各种净化处理技术的优缺点,介绍了炼油厂污油的资源化回收方案,即常减压装置回炼和延迟焦化装置掺炼,对炼油厂污油处理技术进一步的研究方向进行了展望。