黄土高原地区风力发电结构-承台-桩基数值模拟

通过现场勘查和室内土工试验,取得风电场地基土和回填土参数,结合风力发电结构设计资料,利用ABAQUS建立风力发电结构-承台-桩基有限元模型。数值模拟结果与机组现场实测数据对比表明:承台基础环自重和回填覆土沉降的模拟结果与实测数据基本一致;上部结构吊装后,实测沉降值较大,原因主要是吊装过程中大型车辆碾压和吊装完成后风荷载作用。三个阶段数据对比结果表明建模过程正确,模型具有可行性和合理性,为后续施加风荷载,进行黄土高原地区风电机组的更多研究提供参考。     

桶式基础气压模型试验和有限元分析

桶式基础结构是一种适用于软土地基的新型海工结构。为保证结构的可靠性,已对桶式基础使用期的承载力、稳定性和水动力特性进行了大量试验研究,但施工阶段的性状并未得到足够关注。为此制作了1∶8的小比尺模型并进行室内试验,研究设计规定的正压和负压下结构模型的内力、变形和气密性,获取了测点应变-加载时间的关系曲线。采用通用有限元软件ABAQUS对模型进行了弹性有限元分析并与试验结果比较。研究表明,桶式基础模型能承受设计规定的正压力和负压力,模型混凝土和钢筋应变变化规律与加压规律大体相符;弹性有限元分析结果与试验结果基本吻合。     

Hydraulic performance of sewer pipes with deposited sediments.

This paper investigates in-sewer sediment deposit behaviour and its influence on the hydraulic performance of sewer pipes. This evaluation is based on experimental results regarding the mobility of non-cohesive and partly cohesive deposits in a partially full circular pipe. The focus of these tests is on the development of bed forms and friction characteristics. In particular, it is investigated to what extent the bed forms from the non-cohesive and (partly) cohesive sediments affect a sewer's discharge capacity. Based on the laboratory study results and on the existing criteria for sewer design, a generic assessment of a sewer's hydraulic performance is made. The relative discharge factor for a pipe with sediment deposit is analysed in terms of the thickness and roughness of the deposit.     

Automation of on-site observations of chemical suffosion in the foundations of hydraulic structures

Conclusions 1. A method for the real-time determination of water mineralization by means of ion-selective electrodes has been implemented in practical laboratory investigations of chemical suffosion. 2. An analysis of the results of investigations has demonstrated the conceptual feasibility of using calcium ionselective electrodes to significant advantage in automated on-site observations of chemical suffosion in the foundations of head structures situated on gypsiferous and carbonate soils. Translated from Gidroteknicheskoe Stroitel’stvo, No. 7, pp. 26–28, July, 2000.     

单桩与带承台单桩承载性能的对比试验

为研究单桩和带承台单桩承载性能的差异,对单桩和带承台单桩进行了静载试验对比,试验结果表明,在刚性承台的作用下,带承台单桩桩身上部轴力的衰减较慢,产生了侧阻的削弱效应,摩阻力-位移关系曲线出现软化现象,但桩端阻力的发挥得到了增强;在相同桩顶荷载下,带承台单桩中桩顶的沉降量较单桩的桩顶沉降量大。     

软土中大直径超长群桩位移的实用计算方法

从单桩m法入手,提出了软土中大直径超长群桩位移计算的方法。将单桩分析与承台以及群桩分析结合起来,考虑了底部转角、有效桩长的作用,以及大直径超长群桩受水平力转动所引起的弯曲和压缩的影响。利用Matlab软件,对所推得的公式进行编程,计算验证,讨论了不同桩距和不同桩径时的各种情况。将计算结果代回单桩公式中,可得桩身的位移和应力曲线,整个计算方法成为一个闭合循环的求解过程。以安徽省某长江大桥锚碇基础的群桩为例,选用实际数据进行分析计算,并与三维有限差分法的计算结果进行对比,发现该方法具有较高的实用价值。     

河西水库坝体填筑质量调查与分析

通过现场勘察及室内试验的方法,对山东省河西水库坝体的填筑质量进行分析和评价。分析结果表明,坝体心墙的壤土结合效果以及土料质量良好,但部分标段的抗液化能力弱,防渗性能不佳。根据坝体存在的问题,提出了增强填筑质量的相应措施,该研究对坝体的除险加固,安全隐患的消除以及水库效益的发挥有着一定的指导作用。     

Distribution and release of 2,4,5-trichlorobiphenyl in ice

The distribution of persistent organic pollutants(POPs) in ice and the release of POPs from ice during ice melting have an important influence on the eco-environment and water quality of a river. Through laboratory simulation experiments, the distribution and release of 2,4,5-trichlorobiphenyl(PCB29) in ice and the partition coefficients of PCB29 in ice water at different temperatures, concentrations, and p H levels were studied. The results showed that, at different temperatures and concentrations, the concentration of PCB29 in ice increased progressively with depth. The modes of release of different concentrations of PCB29 from ice were obtained. A large amount of PCB29 was released rapidly in the first melting period, and then the remaining PCB29 was released uniformly. The p H value dominated both the distribution and late release of PCB29 in ice. In ice water, at different temperatures, concentrations, and p H levels, the majority of PCB29 entered the water, and a lesser amount remained in the ice. Finally, laboratory experiment results were verified with field investigations. A theoretical framework is provided by this research of the behavior of POPs in ice under different environmental conditions, but a more quantitative understanding of the behavior of POPs in ice will need to be developed through further laboratory studies combined with field investigations.     

Corrected correlations between the capacity and levels of the Ust'-Khantaika hydroelectric power plant

Using the Ust'-Khantaika hydraulic power system as an example, results are presented from investigations to obtain corrected relationships between the capacity and water levels of the reserve by taking into account the increase in the capacity as a result of deformation of the bed of the reservoir and banks associated with defrosting of permafrost rock. A precise curve expressing the correlation V=f(z) of the reservoir during its lifetime is needed to arrive at a proper selection of the optimal operating mode of the hydroelectric power plant. Recommendations are presented for further investigations intended to verify the precise dependences of the capacity on the levels of the reservoir to correct the hydroeconomic and hydropower indicators of the Ust'-Khantaika reservoir.Translated from Gidrotekhnicheskaya Stroitel'stvo, No. 3, pp. 19–23, March, 1995.     

Hydraulic investigations of the outlet structures of the Zeya hydraulic development

Conclusion The long-term conditions for passage of water and ice during all the construction stages of the Zeya hydroelectirc plant, which were carried out in close contact with the design organizations (Lengidroproekt), made it possible to introduce into the project several changes for ensuring safe operation of the structure. The existing data on the actual hydraulic conditions for passage of floods during the first construction stages show good agreement between these conditions and the results of the laboratory investigations. Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 6, pp. 5–8, June, 1976     

电排站排水管道承台的施工及计算分析

电排站排水流道结构经多年运行,会因地基沉陷、荷载增加而产生不同程度的损伤,建设新承台保持工程原有功能非常必要,本文通过运用灌浆技术对管道建立了新的管床承台,有助于管道继续发挥其排水功能。     

Carbamazepine, diclofenac, ibuprofen and bezafibrate--investigations on the behaviour of selected pharmaceuticals during wastewater treatment.

Numerous investigations in different European countries observed various pharmaceutically active compounds (PhACs) in notable concentrations in the aquatic environment. Further determinations found the effluents of sewage treatment plants (STPs) to be significant sources for the entry of pharmaceutical residuals to rivers, streams and surface waters. Due to those pathways the knowledge about the elimination of these substances and their behaviour in wastewater treatment plants (WWTP) is elementary for protection of an intact aquatic environment. Since the sludge retention time (SRT) is the most important parameter for the design of STPs, its influence on the reduction rate of these PhACs in the wastewater treatment process was investigated. To study this influence of the SRT on the elimination of PhACs, lab scale plants have been operated with different sludge retention times. The results of the laboratory experiments have been validated analysing various STPs within a wide capacity range and operating at different SRTs. This report describes the determinations observed on the antiepileptic drug Carbamazepine, the two antiphlogistics and analgesics Diclofenac and Ibuprofen and the lipid regulator Bezafibrate.     

Experience in determining the water stability of rocks by the ultrasonic method

Conclusions A method of obtaining a number of indices evaluating the water stabiliby of soil was developed on the basis of ultrasonic sounding. In addition to the softening ratio and degree of swelling and shrinkage, the comparability of which with the standard indices of the same name is proved by actual data, the possibility of determining the type of weathering and degree (index) of weathering by the new method is also shown. The prospects of the practical use of the method is related to rejection of labor-intensive laboratory investigations as well as to the possibility of a more broadened engineering-geologic evaluation of soil with respects to its water properties. Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 11, pp. 32–36, November, 1997.     

碟簧桩帽壳体的动力分析

碟簧桩帽是一种新型的桩帽结构 .它可以在保持冲量不变下减轻冲击力 ,避免桩头的冲击破坏 .在实用中桩帽壳体下部常常出现裂缝 ,为此 ,将桩帽结构简化为一维杆系的计算简图 ,应用动力分析中的应力波解答进行分析 ,并考虑结构的应力集中现象和反复荷载的疲劳作用 ,得出了桩帽的应力解答 ,从而找出了桩帽壳体下部开裂的原因 .文中进一步对减少应力集中现象的加肋、加厚等加固措施做了讨论分析     

Effect of aeration on joining of pools by means of a hydraulic jump

Conclusion As is seen from the aforesaid, the problem of the effect of aeration on joining of pools by a hydraulic jump remains, as before, unsolved, since the aforementioned works, including the official standards on hydraulic calculations [1, 13], contain quite contradictory recommendations. More thorough generalizations of the available experimental data and accumulation of results of new laboratory and full-scale investigations with measurement of local characteristics of two-phase, aerated water flow are needed for solving this problem. Translated from Gidrotekhnicheskoe Stroitel'stvo. No. 11, pp. 42–45, November, 1996.     

土坝坝体注水试验的影响因素

针对目前病险土坝地质勘察中选取坝体土渗透系数较难的问题,采用适合土坝坝体注水试验的渗透系数计算公式,分析了注水试验参数对渗透系数的影响,并对常水头与降水头室内渗透试验与现场注水试验成果进行对比分析。结果表明:土坝坝体注水试验水头和初始水位对试验结果影响最大,注水试验水头过高易产生坝体水力劈裂,造成坝体土渗透系数偏大的假象;大坝坝体填土均适合进行常水头及降水头注水试验;土坝坝体土渗透系数的确定应综合注水试验及室内渗透试验的成果。     

桩承式加网复合地基桩土共同作用分析

采用剪切位移法分析了桩承式带桩帽单桩与桩间土的相互作用,得出均布荷载下带桩帽单桩的桩身位移、轴力公式。用ABAQUS有限元软件对带帽单桩进行三维数值分析,将数值计算结果与解析公式结果进行比较,计算表明解析公式计算出的桩身轴力、桩顶沉降、路基表面沉降和有限元计算值接近。将现场实测数据与解析计算结果进行比较,解析计算的沉降结果和实测沉降数据较吻合,说明所提出的解析法计算公式准确性较好,对工程应用有一定的参考价值。     

Short communications monitoring the impact of dams on the downstream physical environment in the tropics

In the main, the assessment of environmental impact of dams is not undertaken in feasibility surveys of dam-related projects in the Tropics, as it should. Consquently, post-implementation investigations (mostly by research students) continue to reveal undersirable effects. The lack of appropriate data on which to base predictions in proposed projects, or to assess environmental impacts in ongoing ones, is a major problem. It is argued that continuous monitoring of existing projects can help to fill this data gap. Such monitoring should cover the entire basin affected, taking into account environmental variables of the upstream, reservoir, and downstream systems. This paper considers the downstream system. Variables of importance include: soil erosion and sediment yield; channel morphometry; discharge and runoff pattern and volume; and changes in vegetation cover, water chemistry and water quality. Field measurements and observations, laboratory analyses, and statistical inferences are required to yield acceptable results. Such results are expected to enhance a better understanding (through impact assessment) and management of existing projects, on the one hand, and to aid wise predictions (at the feasibility stage) of environmental effects of new projects, on the other.     

Gemeinsame österreichisch-ungarische Sedimentforschung im Rahmen des EFRE-Projektes SEDDON

The multiple uses of the Danube River for navigation, hydropower production and as a drinking water supply influence its ecological quality. Flow restrictions due to regulation as well as impacts on the sediment regime such as retention in the catchment area and interruption of the sediment continuum result in changes of the hydromorphological structures and can produce major problems in the context of sediment management. In light of these facts, cross-border investigations of sediment transport at the Danube River are called for. As there are no uniform research approaches shared by Austria and Hungary, the EU-funded project SEDDON (Sediment Research and Management at the Danube River) aims to compare different monitoring and modeling techniques used to determine sediment transport, and to develop mutual solutions. Further, the laboratory equipment currently used for hydraulic model experiments is evaluated and a research channel with a free flowing discharge of up to 10 m³/s without pumping will be constructed, allowing large-scale joint laboratory tests concerning sediment to be performed.