自来水管道施工技术分析

近年来，随着经济和社会的飞速发展，城市自来水管网的覆盖范围越来越广泛，自来水管道的施工环境越来越复杂，给自来水管道施工带来巨大的挑战。自来水管道施工技术水平的高低直接决定自来水管网工程的质量。本文围绕自来水管道施工，首先简单介绍自来水管道工程的施工工序；然后列举目前自来水管道施工过程中常见的问题，最后从自来水管道施工前的测量、沟槽的开挖、管道铺设施工质量的控制、沟槽回填四个工序进行施工技术要点分析。     

市政管道开槽施工技术研究

本文从沟槽开挖与回填、管道敷设、管道质量检验与验收等方面对市政管道开槽施工技术进行了浅要的分析与研究,并提出了一些意见和建议。     

如何加强市政道路排水管道施工技术控制

【摘要】对市政排水管道的施工技术要点进行分析，其中包括施工前的准备工作、沟槽开挖、管基施工、管道安装、检查井施工、闭水试验以及沟槽回填等工作。     

输水工程中PCCP设计应用规范化的探讨

1引言 随着国内PCCP管道的推广使用,长距离输水管道工程规模也不断扩大,承包人与建设方、监理单位、设计部门、施工安装单位在工程进展过程中的相互配合日益紧密,但在实施过程中也出现了各方因习惯、理解的不同,造成对合同、规范、执行等方面的偏差和冲突。本文总结了我公司多年来特别是2001年山西万家寨引黄工程中积累的经验和一些积极的尝试,就PCCP管的设计工作过程加以描述,希望在PCCP行业形成一个相对固定的流程,为国内PCCP更广泛的推广和健康发展做一点有意的探讨。     

浅析PCCP管道的安装工艺方法

本文介绍了PCCP管道的基本情况与发展历史,以及在本工程中PCCP管道的应用情况,另外着重介绍了在工程中PCCP管道的施工工艺方法,包括场地清理、测量放线、管沟基槽土方开挖、PCCP管道运输、存放及现场检验、石屑垫层施工、PCCP管的吊装就位及安装,特别着重介绍了在本工程中独创的"油泵液压拽管法"的施工工艺,以及与传统方法相比较所独具的优点。     

水利供水工程中大口径PCCP管道施工技术

在当前水利供水工程中,PCCP的施工会对地下水运动和土体沉降产生不利影响,而且后期运行阶段也存在管内水压不稳定等问题,使水利供水工程面临一定风险。为解决这一问题,该文对水利供水工程中大口径PCCP管道施工技术进行研究。通过大口径PCCP管道场内运输与装卸、PCCP管道铺设安装、PCCP管道对接、接头水压检验这四部分,提出一种全新的施工技术。实例应用结果证明,将该文设计的新的施工技术应用到水利供水工程项目中,可以在施工阶段能够保证地下水位变化和土体沉降变化在合理范围内,并且可以使PCCP管道在后期运行阶段的管内水压稳定。     

排水管网设计与管道施工质量

排水管网设计与管道施工质量对于整个排水工程的投资，以及日后的使用效果和维护成本都具有很重要的指导性意义。城镇环境工程建设发展迅速，作为配套设施的排水管网设计与建设资金、居民生活及市容环境关系密切。本文简要介绍了排水管道工程的沟槽开挖与回填、沟槽支撑、地下水排除、管基处理及管道铺设和检查井砌筑等施工环节．为排水管网设计与管道施工质量提供借鉴。     

浅析PCCP管道施工技术

PCCP管施工技术性、专业性较强,施工过程中,必须严格按照施工图纸和设计技术要求进行施工,做好对施工过程的控制,确保PCCP管道的安装质量。     

长输管道盾构隧道地质勘察设计探究

近几年来,盾构隧道在一些较大的长输管道工程中的运用已经相当普遍,该项技术能够成功穿越特大型河流的实例也是屡见不鲜,譬如我国的西气东输工程,其中的三江口长江穿越、忠武输气管道工程的红花套长江穿越及城陵矶长江穿越都采用了长输管道盾构隧道穿越方案。同样,在我国地铁上也采用了此项技术。     

PCCP管道施工技术措施

本文针对PCCP管道施工方案与技术方法与现场的控制措施进行了分析与探讨。     

油气管沟槽爆破开挖

介绍了沟槽爆破技术在油气管线建设中的应用概况,重点介绍了药包布置、爆破参数选择、起爆网路设计等技术问题.此次工程经验对类似工程有一定的借鉴价值.     

Hydration mechanism of a novel PCCP + DCPA cement system

A novel partially crystallized calcium phosphate (PCCP) + dicalcium phosphate anhydrous (DCPA) system bone cement was introduced and the mechanism of the hydration was studied by means of solubility product constant (K _sp), XRD, pH value, and BET. Results showed that DCPA was more soluble than PCCP and HA was the most insoluble compound, and DCPA disappeared fast during hydration of the cement. Therefore, the mechanism of the hydration in the PCCP + DCPA system cement was the dissolution and hydrolysis of DCPA and PCCP. And their by-products H₃PO₄ and Ca(OH)₂ reacted through a acid-base neutralization reaction, thus the DCPA and PCCP dissolution and hydrolysis process happened until DCPA and/or PCCP was exhausted. As the conserving time prolonged, fine nano-scale pores were formed due to the hydroxyapatite precipitated into the pores, which were occupied by water before.     

中硬岩管沟爆破对近距离既有管道的影响

为研究中硬岩管沟爆破时10~20 m范围内既有并行管道所受到的影响,进行现场爆破试验,并采用ANSYS/LS-DYNA数值模拟软件来研究既有管道的地表质点振速峰值和管沟成型效果,得出适用于中硬岩地段管沟开挖的爆破参数,并分析了既有管道迎爆面和背爆面的振动响应。研究表明:管沟爆破试验的振速均能保证既有管道的安全,试验2^#的爆破参数更适合中硬岩岩石;垂直地表方向（Y方向）的质点振速峰值最大,且振动速度随着爆心距的增大呈非线性减小;既有管道在迎爆面受到的扰动大于背爆面,迎爆面Y方向的应力、振速均最大。     

Failure analysis of a natural gas pipeline

A L390 natural gas pipeline exploded in 2011 in China. Macrofracture examination, thickness measurement, chemical composition analysis, metallographic inspection, mechanical property testing, fracture scan electronic microscopy examination and environment analysis were conducted to the burst pipeline. The results showed that Stress Corrosion Cracking (SCC) generated in the mechanical damaged zone of the pipeline was the reason of the failure. This kind of cracking was induced by Cl⁻ and HCO₃⁻ in near neutral corrosive medium of pH value. The stress concentration was induced by the groove damage under inner pressure.     

预应力钢筒混凝土管端口打磨机器人的压紧力可靠性分析

预应力钢筒混凝土管（prestressed concrete cylinder pipe,PCCP）在水利工程、工业供水等领域得到广泛应用。针对现有PCCP端口打磨方法效率低、打磨质量难以保证等问题,创新设计了一种PCCP承、插口打磨机器人。首先,根据工作服役环境要求,对端口打磨机器人进行了结构设计与样机制作,并通过现场试验分析该机器人的打滑失效问题;其次,根据打磨机器人克服摩擦力环绕承、插口作周向转动的打磨过程,在进行力学分析基础上建立其压紧力模型及可靠性模型,并采用随机摄动方法分析了整个打磨过程的动态可靠度,得到该打磨机器人可靠性最低的关键部位;最后,对影响端口打磨机器人可靠性的参数进行了灵敏度分析,得出使端口打磨机器人最快趋向可靠的参数为从动轮半径。研究结果为研发具有自主知识产权的大型PCCP自动化制造装备及进行下一步可靠性优化设计奠定了基础。     

设沥青夹层水泥混凝土路面早龄期力学行为与作用效应研究

基于水泥混凝土路面早龄期三维有限元力学分析程序,对设沥青夹层面板结构早龄期阶段力学行为和性状形成的结构效应、沥青夹层效应进行了研究。研究发现,早龄期阶段固化温度、混凝土的徐变和硬化历程与环境场叠加作用,会引起面板更大的早期板角翘曲和脱粘,以往传统分析理论忽略了此方面影响。设沥青夹层结构比无夹层直接加铺路面脱粘面积小、翘曲变形更大。沥青夹层面板早龄期增大翘曲、脱粘的结构效应与特定重载交通共同作用下可能产生对路面板疲劳寿命不利的影响。对设沥青夹层加铺结构建议采用刚度较大的基层,夹层厚度宜在30 mm以内,沥青夹层混合料模量宜选低值。     

三峡陈家冲料场超径石解小的爆破研究

本文通过超径石解小各种爆破方法和破碎手段的探讨和研究 ,解决了三峡料场大规模超径石二次破碎的方法和技术方案 ,并在现场实践中取得了很好的爆破效果。     

PCCP管实地核查工作中技术标准的活用

本文介绍了PCCP管产品标准的修订背景和特点;结合PCCP管企业实地核查工作,对如何有效应用产品标准及相关标准谈了自己的体会,希望与其他专业审查员共同分享。     

Role of Base Plate Rotational Speed in Controlling Spheroid Size Distribution and Minimizing Oversize Particle Formation During Spheroid Production by Rotary Processing

The occurrence of material adhesion and formation of oversize particles in the product yield during one-pot spheroid production by rotary processing leads to a less predictable process and a decrease in the usable portion of the total product yield obtained from each production run. The use of variable speeds of the rotating frictional base plate during the spheronization run was investigated for achieving optimal spheroid production. When the base plate speed was increased during liquid addition, the greater centrifugal forces generated improved liquid distribution and the mixing of the moist powder mass, resulting in a decrease in the amount of oversize particles formed. When the base plate was maintained at a high speed throughout the run, the amount of oversize particles and mean spheroid size increased, and a greater “between batch” mean spheroid size variability was also observed. The findings showed that, when higher speeds were used, the residence time must be adjusted accordingly to avoid excessive coalescence and growth while maintaining even liquid distribution. A “low-high-low” speed variation during rotary processing may be used to produce spheroids with a narrow size distribution and with a minimal amount of oversize particles in the total product yield.     

Role of base plate rotational speed in controlling spheroid size distribution and minimizing oversize particle formation during spheroid production by rotary processing

The occurrence of material adhesion and formation of oversize particles in the product yield during one-pot spheroid production by rotary processing leads to a less predictable process and a decrease in the usable portion of the total product yield obtained from each production run. The use of variable speeds of the rotating frictional base plate during the spheronization run was investigated for achieving optimal spheroid production. When the base plate speed was increased during liquid addition, the greater centrifugal forces generated improved liquid distribution and the mixing of the moist powder mass, resulting in a decrease in the amount of oversize particles formed. When the base plate was maintained at a high speed throughout the run, the amount of oversize particles and mean spheroid size increased, and a greater “between batch” mean spheroid size variability was also observed. The findings showed that, when higher speeds were used, the residence time must be adjusted accordingly to avoid excessive coalescence and growth while maintaining even liquid distribution. A “low-high-low” speed variation during rotary processing may be used to produce spheroids with a narrow size distribution and with a minimal amount of oversize particles in the total product yield.