非开挖水平定向钻机拉管施工技术探析

随着非开挖施工技术在水利工程中得到广泛应用，对减少和控制河道、堤防、道路等管线重复开挖，改善现场作业环境，加快施工速度，节约工程投资，推动水利发展具有重要意义。通过南水北调丰县沛县尾水资源化利用及导流工程———大沙河拉管工程，探讨非开挖水平定向钻施工技术及其应用。     

定向拉管非开挖技术及后处理措施在引江供水工程中的应用

随着城市化进程的加快,市政基础设施建设与日俱增。非开挖施工解决了常规开挖施工对居民正常生活的干扰和对交通、环境、周边建筑基础的破坏及不良影响。结合过秦淮河拉管工程,对非开挖施工工艺在过河工程中的应用进行了阐述,并对拉管的后续堤防加固措施进行了叙述,对排水管道施工中广泛应用非开挖技术有较强的借鉴意义。     

顶管技术在市政给排水施工中的应用

1.概述目前,随着我国社会经济的快速发展,城镇化建设的步伐加快及城市高层建筑、居民生活水平提高和基础设施的不断兴建,地下工程的建设和应用日益广泛,开挖施工方法显现出很大的局限性和不足之处。因此,非开挖铺管技术应运而生。非开挖铺管施工技术是指在不开挖地表破坏路面的条件下铺设各种地下公用设施的一种技术和方法。与开挖施工法相比,非开挖施工技术具有不影响交通、不破坏环境、施工周期短、综合施工成本低、社会效益显著等优点。     

小湾水电站右岸高边坡大区开挖爆破网络技术的应用

小湾水电站是世界级工程，地质条件复杂，施工难度大，技术要求高，施工工期紧，施工强度高，开挖工程量大。右岸开挖边坡高达600m。采用大区深孔梯段爆破，非电毫秒微差起爆网络；爆破网络可靠性对作业循环及施工进度的影响较大，保证大区网络的可靠性是开挖爆破的关键，我们采取一系列的技术措施，提高了网络的可靠性，保证了开挖爆破的质量，加快了开挖施工进度。     

非开挖牵引技术在管道工程中的应用

介绍非开挖技术的特点和非开挖牵引铺管技术的施工工艺流程，通过在给水工程中的应用，表明非开挖技术具有良好的社会效益和经济利益，值得在室外给水工程中大力推广。     

浅谈非开挖水平定向钻机拉管施工技术

随着城市的发展，地下管道承担着城市居民生活用水的供应和与日俱增的城市污水的排放。然而管道施工时，受市政交通的影响，城市地下管道工程明开槽的时代即将成为过去，非开挖施工技术势将越来越多的在城市地下管道工程中得到应用。但是，非开挖施工技术在城市地下管道施工中如何实施？本文将针对非开挖拉管施工技术进行整体的分析探讨。     

国外某工程施工导流洞爆破开挖技术方案的优化

国外某水利水电工程施工导流洞工程的地质条件十分特殊，各种地质结构面超常发育。工程地质特性决定爆破开挖施工技术方案，通过对原爆破开挖施工技术方案和优化后爆破开挖施工技术方案进行多方面比较，最终选择优化爆破开挖施工技术方案，实践表明，优化方案在确保施工安全、改善施工质量的同时，降低了施工成本，加快了施工进度。     

国外某水电工程导流洞爆破开挖方案优化

国外某水利水电工程施工导流洞，为整个枢纽工程的关键控制性工期项目，工期紧迫。而导流洞工程的地质条件十分特殊，各种地质结构面超常发育。工程地质特性决定爆破开挖施工技术方案，通过对原爆破开挖施工技术方案和优化爆破开挖施工技术方案多方面比较后，最终选择优化爆破开挖施工技术方案作为最终实施方案。施工实践表明，优化方案是切实可行的，在确保施工安全、改善施工质量的同时，降低了施工成本，加快了施工进度。     

非开挖技术在水库除险加固输水涵管重建工程中的应用

非开挖技术作为穿越地面及障碍物新技术,具有施工进度快、施工安全有保障、建后管理更方便等优势,目前在水库除险加固工程中得到了广泛的应用。文章主要针对非开挖技术在水库除险加固输水涵管重建工程中的应用展开了探讨,通过结合具体的实例,对非开挖水平定向钻进技术作了简介,并详细阐述了非开挖技术的施工工艺和注意事项,以期能为有关方面的需要提供有益的参考和借鉴。     

金钟水利枢纽工程引水隧洞工程施工技术

随着施工机械设备和工艺的发展,水利工程经常遇到隧洞开挖工程其施工进度不断加快,但是对于小断面开挖的长隧道,仍然存在一些制约因素,如随着开挖进尺的增加,开挖设备和通风排烟的供风压力损失和供电电压损失直接影响开挖效率和安全文明施工。文章吸取长隧洞小断面开挖工程的成功经验,针对金钟水利枢纽工程引水隧洞开挖的实际情况进行技术方案的比选,找到较合理的施工参数,提高了开挖质量和进度,类似工程可以借鉴。     

地下厂房施工过程的三维非线性数值模拟分析

根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。     

Evaluation of freshwater mussel relocation as a conservation and management strategy

The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects.     

基于模型试验的河床砂砾石层基本特性研究

为了经济可靠地确定深厚覆盖层的基本特性参数,以大渡河双江口水电站坝基河床砂砾石层基本特性研究为工程背景,进行大尺寸模型试验,研究河床砂砾石层的旁压模量和动探击数随密度、级配以及上覆压力的变化规律。根据室内模型试验结果,结合现场旁压试验及钻孔试验成果,推断出坝址区河床砂砾石相关层位的密度,并依此进行砂砾石室内力学试验,获得设计所需力学参数。研究成果可为深厚覆盖层基本特性测试提供新的方法。     

基于BP神经网络-马尔科夫链模型的隧道围岩位移预测

在隧道工程施工中,围岩位移预测起着很重要的作用。将BP神经网络-马尔科夫链模型引入到隧道围岩位移预测中来,通过对训练样本的学习,利用BP神经网络实现了对位移时间序列的滚动预测,同时得到了实测值与预测值的相对误差;在此基础上利用马尔科夫链对相对误差进行修正,有效地提高了预测结果的精度。并将该模型应用于某公路隧道拱顶下沉位移时序预测中,结果表明该模型具有精度高、科学可靠的特点,为隧道围岩变形的预测提供了新的途径。     

Short communication. Pipelines as a refuge for freshwater snails

In the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment.     

浙江省水域调查录入系统的设计和应用

浙江省水域调查录入系统将调查数据与电子地图相整合,对分类水域数据进行统计计算,并对输入数据进行合理性和完整性检查,得到调查范围内现有水域的详细数据,实现了水域调查数据输入、计算、统计和查询的数字化管理,提高了工作效率和工作质量,为各地下阶段水域保护规划编制和水域管理工作提供了数据支持。对该系统的设计原则、功能和技术设计等作了介绍。     

Automated system for removal and pneumatic transport of fly ash from electric precipitator hoppers

A system for removal and pneumatic transport of fly ash is examined, in which air pulses act on batches (pistons) of ash formed in a duct. Studies are made of the effect of several physical parameters on the force required to displace a piston of ash and these serve as a basis for choosing a system for removal and pneumatic transport of ash simultaneously from several hoppers of an electric precipitator. This makes it possible to separate the ash particles according to size without introducing additional components. Formulas are given for calculating the structural and dynamic parameters of this system and measurements of indirect dynamic parameters are used to calculate the input-output characteristics of the system. In order to optimize the system, configurations for summing several ducts into a single transport duct for pneumatic ash transport are proposed. Some variants of dry ash utilization and the advantages of producing of size-separated particles are considered. __________ Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008).     

The flood pulse advantage and the restoration of river-floodplain systems

The ‘flood pulse advantage’ is the amount by which fish yield per unit mean water area is increased by a natural, predictable flood pulse. Evidence for this increase is presented from tropical and temperate fisheries. It is argued that increasing multispecies fish yield by restoring the natural hydrological regime is consistent with increasing production of other trophic levels and with restoration from ecological and aesthetic viewpoints. When applied to a river-floodplain system, this restoration would provide a large, self-sustaining potential for recreation, commercial exploitation, and flood control. An interim ‘natural flood pulse’ restoration approach is proposed for systems modified for navigation. This approach approximates the natural hydrological regime in a river reach and is intended as a first step in the long process of restoring the watershed.     

基于CT-连续加荷水泥乳化沥青混凝土细观损伤规律研究

利用CT技术对水泥乳化沥青混凝土的细观损伤过程进行实时扫描观测,获得了混凝土试件在连续加荷下的CT图像。通过采用直观分析法、CT数分析法、CT数与损伤变量关系3种方法分析表明,水泥乳化沥青混凝土的破坏过程可分为压密、扩容、裂纹扩展、破坏4个阶段,同时混凝土在受压过程中具有韧性,在极限荷载之前各断面处于压密和微扩容的强化阶段,极限荷载之后混凝土从损伤到破坏发展比较平稳。     

浅谈天湖水电站水轮机运行故障及处理措施

简述天湖水电站投运以来各种故障的表现形式，分析其原因，提出了相应的处理方法及措施，并对合理利用国内外设备提出建议。