Dynamic response and failure process of horizontal-layered fractured structure rock slope under strong earthquake

Rock slope with horizontal-layered fractured structure(HLFS)has high stability in its natural state.However,a strong earthquake can induce rock fissure expansion,ultimately leading to slope failure.In this study,the dynamic response,failure mode,and spectral characteristics of rock slope with HLFS under strong earthquake conditions were investigated based on the large-scale shaking table model test.On this basis,multiple sets of numerical calculation models were further established by UDEC discrete element program.Five influencing factors were considered in the parametric study of numerical simulations,including slope height,slope angle,bedding-plane spacing and secondary joint spacing as well as bedrock dip angle.The results showed that the failure process of rock slope with HLFS under earthquake action is mainly divided into four phases,i.e.,the tensile crack of the slope shoulder joints and shear dislocation at the top bedding plane,the extension of vertical joint cracks and increase of shear displacement,the formation of step-through sliding surfaces and the instability,and finally collapse of fractured rock mass.The acceleration response of slopes exhibits elevation amplification effect and surface effect.Numerical simulations indicate that the seismic stability of slopes with HLFS exhibits a negative correlation with slope height and angle,but a positive correlation with bedding-plane spacing,joint spacing,and bedrock dip angle.The results of this study can provide a reference for seismic stability evaluation of weathered rock slopes.

Design and Test of 1/5th Scale Horizontal Axis Tidal Current Turbine

Tidal current energy is prominent and renewable. Great progress has been made in the exploitation technology of tidal current energy all over the world in recent years, and the large scale device has become the trend of tidal current turbine （TCT） for its economies. Instead of the similarity to the wind turbine, the tidal turbine has the characteristics of high hydrodynamic efficiency, big thrust, reliable sealing system, tight power transmission structure, etc. In this paper, a l/5th scale horizontal axis tidal current turbine has been designed, manufactured and tested before the full scale device design. Firstly, the three-blade horizontal axis rotor was designed based on traditional blade element momentum theory and its hydrodynamic performance was predicted in numerical model. Then the power train system and stand-alone electrical control unit of tidal current turbine, whose performances were accessed through the bench test carried out in workshop, were designed and presented. Finally, offshore tests were carried out and the power performance of the rotor was obtained and compared with the published literatures, and the results showed that the power coefficient was satisfactory, which agrees with the theoretical predictions.

Excitation and Detection of Shear Horizontal Waves with Electromagnetic Acoustic Transducers for Nondestructive Testing of Plates

The fundamental shear horizontal（SH0） wave has several unique features that are attractive for long-range nondestructive testing（NDT）. By a careful design of the geometric configuration, electromagnetic acoustic transducers（EMATs） have the capability to generate a wide range of guided wave modes, such as Lamb waves and shear-horizontal（SH） waves in plates. However, the performance of EMATs is influenced by their parameters. To evaluate the performance of periodic permanent magnet（PPM） EMATs, a distributed-line-source model is developed to calculate the angular acoustic field cross-section in the far-field. Numerical analysis is conducted to investigate the performance of such EMATs with different geometric parameters, such as period and number of magnet arrays, and inner and outer coil widths. Such parameters have a great influence on the directivity of the generated SH0 waves that arises mainly in the amplitude and width of both main and side lobes. According to the numerical analysis, these parameters are optimized to obtain better directivity. Optimized PPM EMATs are designed and used for NDT of strip plates. Experimental results show that the lateral boundary of the strip plate has no perceivable influence on SHO-wave propagation, thus validating their used in NDT. The proposed model predicts the radiation pattern ofPPM EMATs, and can be used for their parameter optimization.

Implementation of a Subjective Visual Vertical and Horizontal Testing System Using Virtual Reality

Subjective visual vertical(SVV)and subjective visual horizontal(SVH)tests can be used to evaluate the perception of verticality and horizontality,respectively,and can aid the diagnosis of otolith dysfunction in clinical practice.In this study,SVV and SVH screen version tests are implemented using virtual reality(VR)equipment;the proposed test method promotes a more immersive feeling for the subject while using a simple equipment configuration and possessing excellent mobility.To verify the performance of the proposed VR-based SVV and SVH tests,a reliable comparison was made between the traditional screen-based SVV and SVH tests and the proposed method,based on 30 healthy subjects.The average results of our experimental tests on the VR-based binocular SVV and SVH equipment were−0.15◦±1.74 and 0.60◦±1.18,respectively.The proposed VR-based method satisfies the normal tolerance for horizontal or vertical lines,i.e.,a±3◦error,as defined in previous studies,and it can be used to replace existing test methods.

THE MODEL TEST RESEARCH OF HORIZONTAL FORCE ON RIGID SHAFT FURNITURE IN DEEP MINE

The state of deep mine rigid shaft fUrniture horizontal force calculation in China is introduced and the calculating model of horizontal force is determined. Based on the interaction between hoisting vessel and shaft furniture, the vertical mobel test device is built and a large number of model tests and analyses are carried out. At last, the relationship between horizontal force and hoisting end load, hoisting speed or bunton level interval is gained. The three parameters horizontal force calculating equation of beep mine rigid shaft furniture is given and it can guide the design and calculation of shaft engineering.

In-situ Horizontal Extrusion Test of Herbaceous Root-Soil with Different Root Types

The influence of different types of roots on the soil is complex and still remains unclear.Four in-situ extrusion tests were conducted on two types of root systems,namely fibrous and tap root system,for three plants,Eleusine indica,Potentilla anserine,and Artemisia argyi,according to the classification in Botany,and the thrust-displacement curves and failure patterns of different samples were analysed by comparison to fill the aforementioned gap.Results reveal that the roots can reduce the characteristics of soil brittleness and enhance its capability to resist large deformation,and different root types contribute different effects to the strain-hardening behavior of the root-soil mass.The contribution of the fibrous root system to strength is limited,whilst the tap root system substantially enhances strength and stiffness.Results of failure patterns show that fibrous and tap root systems affect soil solidification and surface cracking reduction.However,the effect of the tap root system depends on the composition of lateral and tap roots:long and rich lateral roots are effective for resisting the creation of cracks,but thick tap roots with few and thin lateral roots may lead to several surface cracks.

Effect of austempering parameters on microstructure and mechanical properties of horizontal continuous casting ductile iron dense bars

In the present research, the orthogonal experiment was carried out to investigate the influence of different austempering process parameters(i.e. austenitizing temperature and time, and austempering temperature and time) on microstructure and mechanical properties of LZQT500-7 ductile iron dense bars with 172 mm in diameter which were produced by horizontal continuous casting(HCC). The results show that the major factors influencing the hardness of austempered ductile iron(ADI) are austenitizing temperature and austempering temperature. The fraction of retained austenite increases as the austenitizing and austempering temperatures increase. When austenitizing temperature is low, acicular ferrite and retained austenite can be effi ciently obtained by appropriately extending the austenitizing time. The proper austmepering time could ensure enough stability of retained austenite and prevent high carbon austenite decomposition. The optimal mechanical properties of ADI can be achieved with the following process parameters: austenitizing temperature and time are 866 °C and 135 min, and austempering temperature and time are 279 °C and 135 min, respectively. The microstructure of ADI under the optimal austempering process consists of fi ne acicular ferrite and a small amount of retained austenite, and the hardness, tensile strength, yield strength, elongation and impact toughness of the bars are HBW 476, 1670 MPa, 1428 MPa, 2.93% and 25.7 J, respectively.

Short-Term Test for the Induction of Lung Tumor in Mouse by Chloroprene

In a previous study by the authors,positive results from both a case-control study and a cohort study were reported.In the present study a short-term test for the induction of mouse lung tumor by chloroprene was conducted to confirm whether chloroprene monomer itself can induce tumors.Kunming albino mice weaned at 2 weeks were subjected to inhaling 0,2.9±0.3, 19.2±1.9,and 189.0±13.3 mg/m^3 chloroprene(GC purity,99.8%)4 h daily(except Sunday) for 7 months.All survivors were killed at the end of the 8th month or when moribund.No lung tumors were found before the 6th month.Thus,survivors at the 6th month were counted as effective animals.Most lung tumors observed were papilloadenomas(50/57),and a few were adenomas(7/57).The tumor incidence in the 2.9 mg/m^3 group was 8.1% in comparison to 1.3% in the control group,with the significance level at P<0.05.The higher the concentration,the higher the incidence.Examination of the multiplicity of tumor induction also demonstrated a dose-response relationship,and the number of tumors per mouse in the 189 mg/m^3 group was significant at P<0.01.1989 Academic Press,Inc.

HORIZONTAL WELL PRESSURE ANALYSIS IN BOX-BOUNDED RESERVOIRS

In this paper, solutions to the 3D transient flow mathematical model for horizontal wells in box-rounded reservoirs are presented. The solutions are derived in Laplace transform domain by employing integral transform and point-source superposition. Both efficient computation of pressure responses and practical technology of oil field application mentioned here may be used to interpret the data from unsteady-state horizontal well testing.

ADPRT-MEDIATED DECREASE OF CELLULAR NAD CONTENT AND THE DETECTION OF CHEMICALLY INDUCED DNA DAMAGE DEVELOPMENT OF A NEW SHORT-TERM SCREENING TEST FOR MUTAGENS

It was found that the DNA-damaging agents N-methyl-N’-nitro-N-nitrosoguanidine（MNNG）,methyl-methanesulphonate（MMS）and 4-nitroquinoline-N-oxide（4NQO）could stimulate ADP-ribosyl transferase（ADPRT）activity and reduce the cellular NAD content in a dose-dependent way.The reduction of NAD after DNA damage could be partially or completelyprevented by ADPRT inhibitors,3-aminobenzamide or nicotinamide,which showed noinfluence on reduction of NAD induced by metabolic blocking agents.Therefore,a simpleand specific method to detect DNA-damaging mutagens by measuring ADPRT-mediateddecrease of cellular NAD content was explored.Using β-naphthofiavone,a mixed functionoxygenase inducer,together with induced or uninduced human amnion FL cells,it was foundthat aflatoxin B1,benzo（a）pyrene,2-acetylaminofluorene,9,10-dimethylanthracene andethylcarbamate could induce the ADPRT-mediated decrease of cellular NAD content,while4-acetylaminofluorene,anthracene,isopropyl-N-（3-chlorophenyl）-carbamate,β-propiolactone,γ-butyrolactone,cyclophosphamide and safrol could not.The results indicate that this isa cheap and specific method to detect DNA damage caused by chemical carcinogens/mutagenswith a spccificity approaching that of the unscheduled DNA synthesis assay.

A STUDY ON THE RELIABILITY OF SHORT-TERM AFB_(1)-INDUCED HEPATOCARCINOGENESIS TEST MODEL

In order to test the reliability of γ-GT foci(γ-glutamyltranspeptidase positive hepatocyticfoci) as a preneoplastic marker in AFB-inducedhepatocarcinogenesis, this experiment was car-ried out for a long period after a short-term invivo test model of AFB-induced hepatocarcino-

Analytical and Experimental Studies on Wave Scattering by a Horizontal Perforated Plate at the Still Water Level

This research investigates water-wave scattering via a horizontal perforated plate fixed at the still water level through analytical studies and physical model tests.The velocity potential decomposition method is combined with an efficient iterative algorithm to develop an analytical solution in which the quadratic pressure drop condition is imposed on the horizontal perforated plate.The analytical results are in good agreement with the results of an independently developed iterative boundary element method(BEM)solution.Experimental tests are carried out in a wave flume to measure the reflection coefficient and transmission coefficient of the horizontal perforated plate,and the analytical results agree reasonably well with the experimental data.The influence of various structural parameters of the horizontal perforated plate on the hydrodynamic parameters of reflection coefficient,transmission coefficient,energy-loss coefficient,and wave force are analyzed on the basis of the analytical solution.Useful results for the practical engineering application of horizontal perforated plates are also presented.

Horizontal Fire Spread in a Contemporary Apartment Based on a Real Fire

The apartment fire tests comprise a set of two full-scale fire experiments in a dwelling building made from pre-fabricated concrete elements in April 2013. Two apartments were nearly identically furnished and fully instrumented with thermocouples, video cameras and gas extraction probes. The apartments were ignited successively whereupon the fire in the second apartment developed freely to post-flashover conditions and got the main focus in this report. The apartment was completely furnished with contemporary furniture and objects, and had an average fire load density for residential occupancy. A full description of the fire load, ventilation conditions and instrumentation are provided. The focus of this report is primarily to obtain conclusions on the horizontal spread of smoke throughout the apartment during the fire growth period. Velocities of smoke spreading were measured to be in the range below 0.05 m/s which means that the smoke migrated over the longest distance throughout the apartment for about 3 to 4 minutes while the flame did not leave the initial fire room. The main aim of the experiments was to collect a comprehensive set of data from a realistic and contemporary fire scenario to validate numerical simulations.

Heat Transfer in Horizontal Copper Tube Heated by Electric Heating Process

Heat transfer from electrical and electronics component is essential for better performance of that electrical system,The maximum heat transfer from that system results long period durability.In most of the system base provided for equipments are very small and placed in a very complicated position.so heat transfer by forced convection is not easy for that purpose.The heat transfer by natural convection is the familiar technique used in electronics cooling;there is huge group of apparatus that lends itself to natural convection.This category consist of stand-alone correspondence such as modems and small computers having an array of printed circuit boards(PCB)accumulate within an area.Natural convection heat transfer in heated horizontal duct drive away heat from the interior surface is offered.The duct is open-ended and round in cross section.The test section is heated by provision of heating coils,where constant wall heat flux mentioned.Heat transfer experiment is carried out for channel of 50 mm.internal diameter and 4 mm thickness with length 600 mm.Ratios of length to diameter of the channel are taken as L/D=12.Wall heat fluxes maintained at q//=300 W/m2 to 3150 W/m2.A methodical investigational record for the local steady state natural convection heat transfer activities is obtained.The wall heating condition on local steady-state heat transfer phenomena are studied.The present experimental data is compared with the existing theoretical and experimental results for the cases of vertical smooth tubes.

串珠状溶洞数量影响灌注桩顶部水平受拉特性试验研究

采用室内模型试验,对比研究串珠状溶洞数量对灌注桩顶部水平受拉特性的影响,为岩溶强发育区嵌岩桩的水平承载力设计提供试验依据.结果表明:1)桩顶水平荷载相同时,上部土层段桩身水平位移、桩身弯矩(峰值)、桩侧土抗力随溶洞数量的增多而增大,单桩水平承载力随溶洞数量增多而明显减弱.2)上部土层段桩身水平位移随桩顶水平荷载增大而增大,桩顶水平位移最大,嵌岩段很小甚至为0;弯矩M-深度z曲线整体呈抛物线形,桩身弯矩在土岩界面和上层溶洞与底板界面呈现2个峰值,弯矩的变化仅仅影响到上层溶洞及其底板,第2层溶洞及其以下的弯矩几乎为0,土岩界面弯矩最大、截面最危险;土抗力p-深度z曲线呈“凸肚”形.3)溶洞数量增加,位置越高,p-y曲线越容易收敛,可以采用p/pub=α(y/y50)β拟合土层段的桩身p-y曲线.溶洞数量对α与β值变化幅度的影响较小,α与β值变化幅度体现p-y曲线随深度变化的敏感度,两者敏感度随溶洞数量增多而增大.4)工程桩刺穿串珠状溶洞时,为了提高单桩水平抗拉能力,建议采用注浆法改善上部岩土性质,加大土岩界面处桩身配筋率,并将桩身嵌入上层溶洞底板一定深度,防止基桩在土岩界面处发生弯曲破坏.

砂床基础沉降作用下覆土卧罐安全性测试平台

卧式储罐常用于油气、危化品的储存,储罐覆土后可减少介质蒸发损耗、缩小与周围临近设施的安全间距,可有效降低爆炸冲击、碎片飞溅产生的破坏,该技术在石油化工行业应用较广。鉴于基础沉降、土体塌陷等地质灾害因素,以及覆土厚度、覆土边坡角度等工程建设因素均会影响覆土式卧罐的安全施工和运行维护,因此设计研制了砂床基础沉降作用下覆土式卧罐安全性测试平台。该平台可模拟卧罐在不同覆土厚度及边坡角度状态下的应变变化,也可模拟砂床基础的不同沉降长度和高度对卧罐安全性的影响;通过该测试平台可直接观测覆土的沉降位移,能够准确测定卧罐的应变以及罐周土压力,为研究卧罐在砂床基础沉降作用下的安全性提供依据。该平台依托于实际工程背景,兼顾工程实际与科研教学,为师生的科研创新提供了新的平台。

自复位浮置物隔震系统的动力试验与数值分析

提出了一种自复位浮置物隔震系统,该系统采用双层正交导轨隔离水平地震,并通过预拉弹簧绳实现自复位。考虑系统摩擦与弹簧绳刚度,建立了自复位浮置物隔震系统的理论模型,完成了不同工况下的隔震系统振动台试验,结果表明输入地震波的加速度峰值越高,隔震系统的隔震率也会相应提升。在输入地震波加速度峰值为0.15、0.2、0.4、0.62 g时,隔震系统平均隔震率分别为50%、58%、75%、82%。在相同峰值的地震波及楼面波地震动输入下,隔震系统均具有良好的隔震效果且能够实现系统自复位。最后建立了浮置物隔震支座-浮置物体系的有限元模型,验证了隔震系统理论模型的有效性。

水平孔多参数综合测试仪器研发与应用

为研究引大济岷工程隧洞岩体特征、岩溶发育特征、地应力特征和地下水特征等,在泸定取水中线方案的引水线路中布置水平钻孔8个,共计2300 m。为满足对水平孔综合测试的需求,研制了一套适用于水平钻孔的存储式综合测井仪器。本文分析了水平孔多参数综合测试仪器各参数测量的基本工作原理;详细阐述了各功能单元的电路构成选型,主要采用DSP微处理器和大规模集成电路,结合传感器技术实现多种参数的综合测量,包括:水平钻孔的压力、温度、自然伽马、声波波速、孔内电视图像。综合测试仪器集成了模拟传感器、模拟调理电路、数据采集、数据处理、信息存储、数据通讯、信息交换、测控软硬件、电脑显示等功能,是水平孔综合测试不可缺少的技术。在引大济岷工程的水平定向孔中成功应用,一趟起下钻解决了水平钻孔的井斜、方位角、压力、温度、自然伽马、孔内电视测试的难题,尽最大可能保证了钻孔的安全及降低了劳动强度。

自然老化服役后板式橡胶支座摩擦滑移性能试验研究

为了解自然老化服役后板式橡胶支座的摩擦滑移性能,取实际桥梁中服役10年的7个板式橡胶支座进行摩擦滑移试验,分析不同竖向压应力下支座摩擦滑移规律,研究自然老化板式橡胶支座的水平弹性刚度、摩擦系数及耗能能力等,并对比人工热老化支座的相关性能。结果表明:相同服役年限的自然老化板式橡胶支座老化程度并不相同;自然老化板式橡胶支座摩擦系数随着竖向压应力的增大而减小,水平弹性刚度随着竖向压应力的增大而增大;压剪作用对老化板式橡胶支座的耗能能力影响较小,但需要注意累积的摩擦滑移会使支座耗能能力降低。自然老化板式橡胶支座(试验值)相较于未老化支座(理论值)的表面摩擦系数有所降低,但水平弹性刚度明显增大;自然老化板式橡胶支座水平弹性刚度增大幅度远高于人工热老化的板式橡胶支座,人工热老化研究严重低估了自然老化对板式橡胶支座的危害。

某核心筒收进水瓶型超高层结构设计关键问题研究

某超高层建筑位于武汉市汉阳区一线滨江区域,整体造型为下大上小逐渐收分的水瓶型,主体结构高度249m,屋面上设51m高塔冠,地上建筑总高度300m。建筑师要求外框柱贴幕墙边布置,导致塔楼大部分柱均为斜柱,在竖向荷载作用下将对楼面体系产生水平分力,设计中通过在楼面梁设置抗拉钢筋及型钢承担水平拉力。核心筒墙体在17、43层进行了转换收进,通过合理的分析及措施,确保了墙体传力路径的合理性。对主体结构进行了风洞试验并进行了相关论证,减小了设计风荷载,节约了结构造价。对结构进行了施工模拟、收缩徐变分析、墙体有限元分析及塔冠分析,结果表明结构设计安全合理。