地下管线竣工测量方法的应用

介绍了地下管线竣工测量的作业过程及作业方法,详细叙述了解析法地下管线竣工测量中的高程测量方法和坐标测量方法,特别是对埋深较大的方沟及大管径做管线竣工测量时。采用无定向法的实际应用及计算方法做了比较详细地论述。     

RTK和全站仪技术在管线工程测量中的联合应用——以西气东输二线温米段为例

常规测量仪器进行管线工程的全线测量,存在着操作繁杂、效率低、精度差、测量成本高等问题。为了提高测量的精度和效率,在西气东输二线工程温米段的工程测量中,尝试着使用了RTK和全站仪技术结合的方法,用全站仪来补测RTK不易准确测量的路段。在很短时间内,完成了全线路的控制、测图、纵横断面测量等外业工作,并保证了各项精度指标符合规范要求。由此说明,联合作业的方法,起到了优势互补的作用,取得了比较好的效果。     

市政管道的全寿命风险评估

市政管道的全寿命风险评估是市政管道风险管理的重要组成部分,准确而有效的评估决策关系到管道建设的成败问题。本文通过对市政管道全寿命周期内单元风险进行识别与分类;采用现有的管道风险技术,和专家评分法等方法对风险因子进行实效因素评分,然后进行市政管道的全寿命风险评估。     

爆管法施工对环境的影响分析

通过对爆管法对环境影响的理论分析,并结合有关的试验进行模拟分析,探讨了爆管法施工产生的碎片对新铺管道的影响,对周围结构设施的影响,重点论述了爆管法施工引起的地表位移。     

An experimental study of seabed responses around a marine pipeline under wave and current conditions

Experiments on three types of soil (d₅₀=0.287, 0.057 and 0.034 mm) with pipeline(D=4 cm) either half buried or resting on the seabed under regular wave or combined with current actions were conducted in a large wave flume to investigate characteristics of soil responses. The pore pressures were measured through the soil depth and across the pipeline. When pipeline is present the measured pore pressures in sandy soil nearby the pipeline deviate considerably from that predicted by the poro-elasticity theory. The buried pipeline seems to provide a degree of resistance to soil liquefaction in the two finer soil seabeds. In the silt bed, a negative power relationship was found between maximum values of excess pore pressure p_max and test intervals under the same wave conditions due to soil densification and dissipation of the pore pressure. In the case of wave combined with current, pore pressures in sandy soil show slightly decrease with time, whereas in silt soil, the current causes an increase in the excess pore pressure build-up, especially at the deeper depth. Comparing liquefaction depth with scour depth underneath the pipeline indicates that the occurrence of liquefaction is accompanied with larger scour depth under the same pipeline-bed configuration.     

Numerical simulation of a partially buried pipeline in a permeable seabed subject to combined oscillatory flow and steady current

Hydrodynamic forces exerting on a pipeline partially buried in a permeable seabed subjected to combined oscillatory flow and steady current are investigated numerically. Two-dimensional Reynolds-Averaged Navier-Stokes equations with a k−ω turbulent model closure are solved to simulate the flow around the pipeline. The Laplace equation is solved to calculate the pore pressure below the seabed with the simulated seabed hydrodynamic pressure as boundary conditions. The numerical model is validated against the experimental data of a fully exposed pipeline resting on a plane boundary under various flow conditions. Then the flow with different embedment depths, steady current ratios and KC numbers is simulated. The amplitude of seepage velocity is much smaller than the amplitude of free stream velocity as expected. The normalized Morison inertia, drag and lift coefficients based on the corresponding force coefficients of a fully exposed pipeline are investigated. The normalized Morison force coefficients reduce almost linearly with the increase of embedment depth and that the KC only has minor effect on the normalized Morison coefficients. It is also found that the permeable seabed condition causes a slight increase on the inline force and has a little effect on the lift force, compared with corresponding conditions in an impermeable bed.     

泉州市地下管线探测经验探讨

系统介绍泉州市地下管线探测成功经验,为我国低纬度地区城市地下管线探测提供参考。     

浅析油气管道短距离水平定向钻穿越技术的应用

油气管道穿越短距离障碍时,一般穿越技术存在工程投资高、协调难度大、环境破坏严重、施工周期长、施工风险高等问题,因此探索一种技术上可行、经济上合理和方便实施的新的（或改善的）施工方式具有较好的经济和社会效益。短距离水平定向钻穿越是通过改善规范要求的技术参数以及施工措施以达到可实施目的的一种施工方式。改善后的施工方式应用灵活、技术措施安全可行,且能缩短工期、节省工程投资。     

管道工程中基于LiDAR的高精度DEM获取

LiDAR技术的广泛应用对空间信息获取手段产生了重大影响,使得DEM的获取更加快速,精度更高,而成本更低。本文以西气东输四线管道工程LiDAR点云数据处理工作为基础,着重探讨了基于LiDAR的高精度DEM获取技术,给出了具体的工作流程,并对所获得DEM成果做了精度分析,对推动我国LiDAR技术的发展做了有益的实践。     

非开挖地下管线修复与更换技术在中国的应用前景

改革开放以来,我国大部分城市抓住发展契机都在搞建设,但计划赶不上变化快,地下管道在建设过程中缺乏长远考虑,遗留了诸多问题。当前,部分管道老龄化,破损严重,急需修复与更换。我们国家多采用明挖法进行施工,而国际上很多国家则运用非开挖地下管线修复与更换技术,与明挖法相比有保护环境,不影响交通,施．Y-隐蔽,社会效益高,技术先进等优点。这项技术在我国还处于初级阶段。技术经验不足,大多需要借用国外的设备。由于我国大城市管道陈旧和道路交通拥堵现象日趋严重,发展该技术迫在眉睫。国际上常用的修复技术有内衬插入法,模压内衬法,折叠内衬法,螺旋缠绕法等。这些方法各有优点,而“刮痧法”和“穿衣法”能兼并其中几种方法的优点。在我们国内市场,运用以上方法成功的案例也有,但并未得到推广。非开挖地下管线修复与更换技术出了应用于市政工程外,还可用于石油管线工程,地质工程等,在国内有巨大市场前景。