纵坡工况下超低重载主动悬挂升降轨迹灵敏度分析

为提高在纵坡工况下超低重载主动悬挂行驶的安全稳定性,设计出一种升降驱动单元升降控制系统,并分别建立其在理想路面与D级路面的纵坡工况下的数学模型,通过对比升降驱动单元路面跟踪曲线与实际输出位移曲线,验证其在两种路况下的跟踪性能。采用一阶轨迹灵敏度分析方法建立D级路面纵坡工况下升降驱动单元灵敏度方程,给出其位移响应对应的各参数灵敏度,建立灵敏度衡量指标,定量分析各参数变化对输出动态特性影响程度的大小。研究结果表明:液压缸活塞有效面积、液压缸等效总容积、液压油弹性系数、比例伺服阀压力流量系数、液压缸总泄漏系数和最大负载的变化对升降驱动单元输出位移动态性能影响很大,这为后续主动悬挂升降驱动单元性能优化提供理论支持。

利用底盘测功机模拟爬坡工况的验证方法探讨

为测试匹配CVT变速器的车辆在极端工况下的动力性能,设计开发在底盘测功机上模拟实际道路工况进行验证的实施方案,以验证动力总成在极端工况下的冷却系统散热能力匹配水平,填补常规耐久性试验中的薄弱验证环节。

基于相关性分析的挖掘机刷坡能耗分析系统

在挖掘机挖掘过程中,缺少对能耗的分析与优化。基于相关性分析,对影响掘进机刷坡工况能耗的重要因素进行分析,得到关键影响因素,利用这些因素进行能耗计算,并且结合信息化管理,基于MySQL和SpingBoot技术,设计了挖掘机能耗分析系统,其具有挖掘机原始数据导入、刷坡能耗及能耗占比情况分析等功能,实现了挖掘机刷坡工况能耗的智能化分析与计算。

系统论述卫片色调与坡向、坡度、坡位、林分龄组、郁闭度的关系

当前 ,人类赖以生存的地球资源与环境面临越来越严重的威胁。如何迅速、宏观、准确、周期性监控资源和环境 ,已被各国和国际环境组织所重视 ,而卫星遥感就具有迅速、宏观、准确、周期性等特点 ,已被各国应用。内蒙古大兴安岭林业调查规划设计院于 1996年松岭林业局森林资源二类调查时就采用了这个先进的卫星遥感技术。现将影响卫片色调的坡向、坡度、坡位、林分龄组、郁闭度的五大因素进行系统研究 ,找出其相关规律 。

Electrical Characteristics of Tangjiawan Landslide in Lixian, Sichuan

A wide range of terrain features and landforms,which are exemplified by intricate geological formations and diverse rock compositions,are found in the western mountainous regions of China.These areas frequently encounter geological disasters.As one of the natural disasters,landslides lead to considerable loss of human life and property.Considering mitigation of the losses caused by landslide disasters,a necessary measure for disaster prevention and mitigation involves conducting detailed investigations and monitoring of landslides,which is also the cornerstone of landslide warning.This study compares and analyzes the feasibility of the magnetotelluric detection method for landslides using the results of engineering geological surveys and landslide monitoring.The study aims to address the scientific problem of the validity of using magnetotelluric methods to detect landslide development processes.The Tangjiawan landslide signal on the left side of the K94+000~K94+145 section of the Wenma Expressway is analyzed by employing engineering geological survey,magnetotelluric detection,landslide monitoring,landslide analysis,and other methods.Analysis results provide the static electrical characteristics of lithology,structure,and groundwater,as well as the dynamic electrical characteristics of landslide development.This study focuses on analyzing the relationship between the methods of magnetotelluric detection and engineering geological surveys and the results of landslide monitoring.The workflow and methods for data collection,processing,inversion,interpretation,and analysis using the magnetotelluric method to detect the dynamic development process of landslides are presented in the conclusion.Preliminary conclusions indicate a strong correlation between the dynamic changes in magnetotelluric wave impedance with the surface displacement of landslides and the dynamic changes in groundwater.The use of the magnetotelluric method for landslide detection and monitoring is a feasible example.The research results can offer certain technical references for the detection and monitoring of landslides using magnetotelluric methods and also provide references and guidance for the selection of diversified landslide monitoring methods in the future.

老路边坡桩对拓宽路堤沉降控制影响的数值模拟

采用二维弹塑性有限元方法,对不同布桩方式下PHC桩桩承式拓宽路堤的变形特性进行了数值模拟分析,研究了老路边坡下布桩减小拓宽路堤沉降和差异沉降的机理。基于沪宁高速公路拓宽工程沉降控制标准,对PHC桩加固区的位置和桩间距进行了优化。研究表明:老路边坡下布桩可以显著地减小拓宽路堤路中心处的最终沉降和路表工后坡率。在路堤高度不超过5 m且软基厚度不超过20 m情况下,桩帽宽1.2 m的PHC桩加固软基时,第一排PHC桩应布设在老路边坡下距老路坡脚不小于4.7 m处,桩间距可放宽至3.0 m。

高速公路拓宽工程地基处理方案商讨

高速公路拓宽工程地基处理设计原则,在于控制新老路基的工后不均匀沉降值和工后沉降坡差在容许范围,以防止路面产生结构性破坏,出现开裂或破坏。地基处理方案的选择应针对路基形式、土层结构及其工程性质、填土高度、路段位置和要求的工期等因素,在确保工程质量的前提下,做到经济合理、技术可行、可操作性强。依据河南省内外高速公路拓宽工程的设计施工经验,提出有关地基处理方案及适用条件,供类似工程参考。

“风、光、火、蓄、储”多能源互补优化调度方法研究

高比例可再生能源并网是全球能源战略发展的必然趋势。为了应对未来大规模具有随机波动特性的可再生能源并网,一方面须要推进灵活性储能与可再生能源联合互补运行,另一方面须要对常规机组运行新工况加以考虑,以实现高比例可再生能源安全经济并网。文章提出了考虑常规机组低负荷运行和爬坡工况的发电成本计算模型,建立了"风、光、火、蓄、储"多能源互补优化调度模型,并提出用动态惯性权值粒子群算法求解,以实现系统总运行成本最小的优化目标。算例分析表明,引入爬坡成本与低负荷运行成本能够真实反映常规机组在平衡大规模风、光电波动性时所增加的成本,并在调度过程中充分权衡弃风弃光损失和平衡波动性所增加的发电成本,为高比例可再生能源并网情况下电力系统多能源互补运行决策提供了支撑。

新型实验钻机行走平台设计及分析

为减轻实验钻机整机重量、增强钻机移动的灵活性,对行走平台进行了优化设计,最大程度地减小行走平台的外形尺寸和质量。通过理论分析,计算行走平台的行走能力。通过液压仿真,模拟钻机的行走及爬坡工况。

DEPTH PREDICTION OF RAIN WATER ON ROAD SURFACE BASED ON ARTIFICIAL NEURAL NETWORK

A model based on the non-linear artificial neural network （ANN） is established to predict the thickness of the water film on road surfaces. The weight and the threshold can be determined by training test data, and the water film thickness on the road surface can be accurately predicted by the empirical verification based on sample data. Results show that the proposed ANN model is feasible to predict the water film thickness of the road surface.

乘用车AT自动变速器油冷系统冷却能力测试方法

本测试方法主要适用于测试AT自动档乘用车的油冷系统是否可以在各种恶劣的工况下,为AT变速器提供足够的散热能力,主要包括模拟车辆热怠速测试、平均油温测试、爬坡工况测试、高速工况测试。

3D deformation effect and optimal excavated design of surface mine

The three-dimensional （3D） deformation effect of the slope engineering under the step-by-step excavation for the Antaibao surface mine was analyzed using the FLAC^3D technique. An optimal excavated scheme with a relatively steeper slope angle of 47° instead of 30° was successfully implemented at the west wall in the geological section 73200 of the mine area, where the 3D effect of the nonlinear large deformation of the slope was taken into account. Based on the above research conclusion, put forward the countermeasures of shortening mining length, excavating by different regions, timely foot backfilling to protect the excavated slope, and monitoring and feedback adjustment by studying the nonlinear effect. The results show that these countermeasures are effective in controlling maximum deformation and increasing the stability of the slope.

Application of dynamic analysis of strength reduction in the slope engineering under earthquake

At present,the methods of analyzing the stability of slope under earthquake are not accurate and reasonable because of some limitations. Based on the real dynamic tensile-shear failure mechanism of slope,the paper proposes dynamic analysis of strength reduction FEM (finite element method) and takes the reduction of shear strength parameters and tensile strength parameters into consideration. And it comprehensively takes the transfixion of the failure surface,the non-convergence of calculation and mutation of displacement as the criterion of dynamic instability and failure of the slope. The strength reduction factor under limit state is regarded as the dynamic safety factor of the slope under earthquake effect and its advantages are introduced. Finally,the method is applied in the seismic design of anchors supporting and anti-slide pile supporting of the slope. Calculation examples show that the application of dynamic analysis of strength reduction is feasible in the seismic design of slope engineering,which can consider dynamic interaction of supporting structure and rock-soil mass. Owing to its preciseness and great advantages,it is a new method in the seismic design of slope supporting.

New algorithm of mine slope reliability based on limiting state hyper-plane and its engineering application

Due to the influence of joint fissure, mining intensity, designed slope angle, underground water and rainfall, the failure process of mine slope project is extremely complicated. The current safety factor calculation method has certain limitations, and it would be difficult to obtain the reliability index when the performance function of reliability analysis is implicit or has high order terms. Therefore, with the help of the logistic equation of chaos theory, a new algorithm of mine slope reliability based on limiting state hyper-plane is proposed. It is shown that by using this new reliability algorithm the calculation of partial derivative of performance function is avoided, and it has the advantages of being simple and easy to program. The new algorithm is suitable for calculating the reliability index of complex performance function containing high order terms. Furthermore, the limiting state hyper-plane models of both simplified Bishop's and Janbu's method adaptive to slope project are obtained, and have achieved satisfactory effect in the study of mine slope stability in Dexing copper open pit.

A new method for the stability analysis of geosynthetic-reinforced slopes

This paper is concerned with the stability analysis of reinforced slopes.A new approach based on the limit equilibrium principle is proposed to evaluate the stability of the reinforced slopes.The effect of reinforcement is modeled as an equivalent restoring force acting the bottom of the slice and added into the general limit equilibrium(GLE) method.The equations of force and moment equilibrium of the slice are derived and corresponding iterative solution methods are provided.The new method can satisfy both the force and the moment equilibrium and be applicable to the critical failure surface of arbitrary form.Furthermore,the results predicted by the proposed method are compared with the calculation examples of other researchers and the centrifuge model test results to validate its correctness and effectiveness.

Reflection of Typhoon Morakot-The Challenge of Compound Disaster Simulation

Climate change has altered locally singletype disasters to large-scale compound disasters because of increasing intensity and frequency of extreme rainfall events.The compound disasters can combine small-scale floods,debris flows,shallow landslides,deep-seated landslides,and landslide lakes into a large-scale single disaster event.Although simulation models and evaluation tools are available for single-type disasters,no single model is well developed for compound disasters due to the difficulty of handling the interrelationship between two successive single-type disasters.This study proposes a structure for linking available single-type simulation models to evaluate compound disasters and provides a useful tool of decision making for warning and planning of disaster reduction.

Kinematic analysis of geosynthetics-reinforced steep slopes with curved sloping surfaces and under earthquake regions

A procedure of kinematic analysis is presented in this study to assess the reinforcement force of geosynthetics required under seismic loadings, particularly for steep slopes which are hardly able to maintain its stability. Note that curved sloping surfaces widely exist in natural slopes, but existing literatures were mainly focusing on a planar surface in theoretical derivation, due to complicated calculations. Moreover, the non-uniform soil properties cannot be accounted for in conventional upper bound analysis. Pseudo-dynamic approach is used to represent horizontal and vertical accelerations which vary with time and space. In an effort to resolve the above problems, the discretization technique is developed to generate a discretized failure mechanism, decomposing the whole failure block into various components. An elementary analysis permits calculations of rates of work done by external and internal forces. Finally, the upper bound solution of the required reinforcement force is formulated based on the work rate-based balance equation. A parametric study is carried out to give insights on the implication of influential factors on the performance of geosynthetic-reinforced steep slopes.

Assessing Soil Erosion Rates on Manually-Tilled Hillslopes in the Sichuan Hilly Basin Using ^(137)Cs and ^(210)Pb_(ex) Measurements

Purple soils are widely distributed in the Sichuan Hilly Basin and are highly susceptible to erosion, especially on the cultivated slopes. Quantitative assessment of the erosion rates is, however, difficult due to small size of the plots of the manually-tilled land, the complex land use, and steep hillslopes. ^137Cs and ^210Pbex （excess ^210Pb） tracing techniques were used to investigate the spatial pattern of soil erosion rates associated with slope-land under hoe tillage in Neijiang of the Sichuan Hilly Basin. The ^137Cs and ^210Pbex inventories at the top of the cultivated slope were extremely low, and the highest inventories were found at the bottom of the cultivated slope. By combining the erosion rates estimates provided by both ^137Cs and 21~Pbex measurements, the weighted mean net soil loss from the study slope was estimated to be 3 100 t km^-2 year^-1, which was significantly less than 6 930 t km^-2 year^-1 reported for runoff plots on a 10° cultivated slope at the Suining Station of Soil Erosion. The spatial pattern of soil erosion rates on the steep agricultural land showed that hoe tillage played an important role in soil redistribution along the slope. Also, traditional farming practices had a significant role in reducing soil loss, leading to a lower net erosion rate for the field.

Soil detachment and transport under the combined action of rainfall and runoff energy on shallow overland flow

Rainfall and runoff energy results in soil erosion. This paper presents new the concepts of rainfall and runoff energy and analyzes the relationship of rainfall energy and runoff energy with sediment transport based on the conversion theory of kinetic and potential energy using artificial rainfall and mechanical calculation. The results show that the ratio of sediment detachment in sloping fallow overland flow increases with the slope gradient,rainfall energy and runoff energy, while the sediment detachment ratio under raindrop impact are significantly higher than those under no raindrop impact. The sediment concentration increases with the slope gradient and rainfall energy; when the slope gradient and rainfall energy are constant, the sediment concentration decreases as the runoff energy increases. Rainfall disturbance coefficients have a logarithmic correlation with the rate of rainfall energy and runoff energy. On the same slope gradient,when the rainfall energy is constant, the disturbance coefficient decreases as the runoff energy increases,while when the runoff energy is constant, the disturbance coefficient increases as the rainfall energyincreases. Rainfall energy results in sediment detachment, and runoff energy is the transportation for erosion sediment. This showed that rainfall energy and runoff energy are important in the sediment detachment and transportation of shallow overland flow.

Characteristics of discontinuities in Heifangtai landslide area in Gansu,China

Loesses are widely distributed all over the world,especially in China.Meanwhile,long-term agricultural irrigation and extreme climate changes have led to frequent geological disasters in the Heifangtai area of Lanzhou,Gansu,China.Of these,landslides are one of the most frequent types of disasters that are harmful to humans and the environment.A landslide is closely related to the lithology,structure,and groundwater of the site and consists of a combination of structure units divided by discontinuities,such as faults,joints,and fi ssures.Therefore,geological surveys,engineering drilling,and trenching are typically used to identify the stratum lithology,structure,and groundwater in order to visually display underground information within a limited depth range.However,these methods have disadvantages.In particular,geological surveys can only describe geological phenomena on the surface,while the cost of drilling and trenching may be high,along with the ineffi ciency of exploration.In this research,the integrated geophysical exploration method was used to analyze the hidden joints,cracks,and other discontinuities and geophysical features of the discontinuities.The results were verified by trench exploration,and large amounts of underground information were obtained,especially the spread and distribution of discontinuities in landslide areas.Such information can be effectively used for carrying out and providing meaningful experiences and lessons in future comprehensive geophysical processing and interpretations related to the prediction and evaluation of landslides.