管道惯性测绘系统研制及应用

针对管道中心线地理坐标信息的测量需求,基于惯性导航原理,研制了以管道内检测器为载体的管道中心线测绘内检测设备,并将其与漏磁内检测器结合进行工程应用。选取了5处已知点对测绘结果进行了验证,测绘结果和实际验证结果表明:研制的惯性导航内检测器能够准确测绘管道中心线轨迹坐标,在校验点间距约为2 km时,5个距校验点约1 km的已知点的平均测绘误差约为1.8 m;通过将惯性导航检测器与漏磁检测器的组合使用,可有效获取管道缺陷的地理坐标信息,提高了管道内检测缺陷检测定位的精度。     

长输油气管道金属损失漏磁内检测技术研究

以管道漏磁内检测器为载体,通过对管体进行在线的漏磁内检测,可以达到量化管道缺陷、避免事故发生的目的。文中介绍了管道金属损失漏磁内检测技术,分析了油气管道漏磁内检测技术原理及漏磁内检测系统组成,利用有限元分析方法研究了管道缺陷尺寸对于漏磁场信号的影响,验证了管道漏磁内检测技术的可靠性。     

基于FPGA的里程轮信号优选算法设计

文中通过对里程信号产生机理进行分析,提出了一种基于FPGA架构的里程优选算法,给出了实现算法的硬件架构图,并设计相应硬件电路和模拟实验。结果表明:该算法可以对3个里程轮脉冲信号进行优选采集,当里程轮处于超速或者停转状态时也能输出正确的脉冲信号。     

内压载荷下X80管道裂纹应力分布规律研究

为了研究内压作用下管道裂纹应力场分布规律,以含有表面裂纹的X80管道为研究对象,对不同形状、不同方向、不同内压、不同尺寸的含裂纹管道进行仿真分析和实验验证。结果表明:裂纹尖端处应力远大于裂纹中心应力。裂纹形状对应力影响作用较小,随着裂纹方向与管道轴向夹角增大,裂纹尖端应力先增大后减小,随着管道内压、裂纹深度、裂纹长度的增大,裂纹尖端处应力随之线性增大。其中,裂纹长度对裂纹尖端应力的影响小于管道内压和裂纹深度。     

已建道路下方新增管廊工程总体方案若干问题讨论

针对已建道路下方新增综合管廊需求情况,通过分析管廊与已建道路下方管线接驳方式、管廊施工对已建道路保护方式、管廊穿越特殊节点处理方式等,为国内类似工程提供借鉴.     

参数化绘制城市工程管线综合图

介绍了城市工程管线综合图参数化绘图技术.该绘图技术有效地解决了城市工程管线综合图的绘图问题.参数化绘制城市工程管线综合程序可直接安装在AutoCAD软件中,并配有可视化交互界面,使设计人员方便、快捷完成城市工程管线综合图的设计绘图工作.     

公路隧道近距离下穿电力管线施工技术研究

为解决杭州市香积寺路西延工程盾构段下穿220 kV半霞线线、半霞线电力管沟横穿东侧明挖段隧道基坑(4#工作井)及燃霞、燃湾线电力管沟与中间明挖隧道基坑呈“L”形交叉等施工难题,首先,通过对盾构施工的影响范围、地表隆陷变化规律以及电力管沟对地表变形适应能力评估的研究,采取优化掘进参数、控制泥水压力、掘进速度、出渣量、盾构...     

城市新建道路工程既有地下管道保护方案研究

根据城市发展需要,城市道路建设与周边用地开发并非同步进行,工程中时常遇到建设用地下方存在既有管道的情况,一般根据管道埋深、管道规模并综合工程可行性及经济性,选取保护或迁移的设计方案。对于大型管道的保护通常采用护管桥涵或者轻质材料换填的方式,两种技术方法各有其优缺点及适用性。依托项目实际情况,探讨合理的管道迁移或保护技术方案,为类似情况的工程提供参考。     

Research on the pipeline walking caused by cyclic increasing soil friction for free deep-sea submarine pipelines laid on even seabed

Pipelines are important to offshore oil and gas development, but suffers from the pipeline walking phenomenon due to cyclic temperature variations—where large axial walking distances threaten the safety of pipeline systems. Current research indicates that pipeline walking is triggered by steel catenary riser (SCR) tension, seabed slopes, or thermal transients. This paper proposes a new driving mechanism for the pipeline walking phenomenon, involving cyclic hardening soil strength. The finite element analysis method was adopted to analyse the soil friction difference induced walking phenomenon, and the influence of key parameters on the gain in soil friction on walking distance was studied. Pipeline walking distances under different drainage conditions in the heating and cooling processes were also calculated, and the impact of the degree of drainage in the heating process was determined. To better understand the new pipeline walking mechanism, theoretical analysis of the walking behaviour under different cyclic soil friction conditions was carried out. Analytical solutions for estimating the pipeline walking distance were also provided, based on the simplified theoretical analysis.     

Mode jumping in the lateral buckling of subsea pipelines

Unburied subsea pipelines under high-temperature conditions tend to relieve their axial compressive stress by forming localised lateral buckles. This phenomenon is traditionally studied under the assumption of a specific lateral deflection profile (mode) consisting of a fixed number of lobes. We study lateral thermal buckling as a genuinely localised buckling phenomenon by applying homoclinic (‘flat’) boundary conditions. By not having to assume a particular buckling mode we are in a position to study transitions between these traditional modes in typical loading sequences. For the lateral resistance we take a realistic nonlinear pipe-soil interaction model for partially embedded pipelines. We find that for soils with appreciable breakout resistance, i.e., nonmonotonicity of the lateral resistance characteristic, sudden jumps between modes may occur. We consider both symmetric and antisymmetric solutions. The latter turn out to require much higher temperature differences between pipe and environment for the jumps to be induced. We carry out a parameter study on the effect of various pipe-soil interaction parameters on this mode jumping. Away from the jumps post-buckling solutions are reasonably well described by the traditional modes whose analytical expressions may be used during preliminary design.