Scanning high-traffic roads unmanned

作者：Kiew Tian Lim

新加坡土地运输管理局（LTA）的座右铭是We Keep Your World Moving。该组织致力于建设大规模快速运输（MRT）系统 - 汤森 - 东海岸线（TEL），该系统增强了从北到南走廊的轨道连通性切割。新的捷运线将大大提高中央商务区和码头湾地区的可及性。

Significantly improving travel time for commuters, the construction of TEL includes 43 kilometres of underground tunnel from Woodlands North Station to Sungei Bedok Station. With 4.5 km of tunnels underneath the dual three-lane heavy traffic Seletar Expressway (SLE), monitoring is of paramount importance where the contractor is to ensure negligible road deformation or disturbance that will affect the traffic flow.

The engineering firm Tritech Engineering & Testing (S) Pte Ltd was contracted to monitor the road surface with a fully automated monitoring system on a real-time basis. To provide this service, due to critical circumstances and high stringent monitoring requirement, Tritech initiated with Leica Geosystems’ monitoring solutions.

Laser scanning and total station in one

使用徕卡新星MS60相乘iStation plus Leica GeoMoS monitoring software v6 and later, Tritech was able to set up an Automatic Road Monitoring System (ARMS) covering a two-kilometres critical stretch of the SLE affected by drilling of the Tunnel Boring Machines (TBM) underneath. The essential laser scanning functionality of the Leica Geosystems MultiStation combined with reflectorless and prism measurements came to the rescue, as prisms installation on the road, which is prone to destruction by passing vehicles, was not an option for this project.

“With the MS60 MulitStation, we were able to setup the ARMS, enhancing productivity as an unmanned measuring system,”Tritech Engineering＆Testing（S）PTE的注册测量师Tor Yam Khoon博士说。有限公司“The system also serves as an effective measuring system delivering the results wirelessly soon after the completion of a measurement epoch.”

The automatic scanning ability of the system enabled quick delivery of deformation information. With GeoMoS image-assisted scan area definition feature, the firm was able to add the defined areas to the measurement cycle. For the firm, this combined solution helped enhance:

• 准确性和可靠性；
• Quick interpretation of monitoring data; and
• Correct remedial decision making.

“Leica Nova MS60 is a good hybrid of total station and laser scanner useful in deformation monitoring of points using glass prisms and surfaces using new Leica GeoMoS n.Vec Technology. In this project of road surface monitoring, successful application of the n.Vec Technology to horizontal surfaces is well demonstrated,”said Dr. Tor.“It is definitely better to derive the vector of deformation from a scan patch of at least 500 readings rather than from a single reflectorless reading.”

在Tritech专有的自动化结构化监控系统中，对项目中使用的八个综合次数的数据进行了整理。自动监测系统，具有四个小时周期的能力，每周7天，对多阶段和地缘人来说，可以转化为减轻人工成本的主要成本。

从在4毫米高的观察平台上在路肩上设置的多阶段收集了数据，相距25 m的四排路面斑块中间。这四个扫描斑块是在穿过白路标记的道路上的行中定义的。定期监视这16个常规扫描贴片。在每个25米的常规监测区域之间，也有相距5 m的“备用”扫描贴片定义。每当有计划或计划外切割器头部干预时，这些备用扫描贴片将被添加到监视方案中，以进行自动监视周期。尽管上述多阶段正在主动监视中，但在TBM进入其监视区域时，将准备前方设置另一个多阶段。

来自国外的支持

对于如此精确的设置，存在最初的挑战。新加坡的Leica Geosystems员工与瑞士的支持人员勤奋合作，以快速诊断设置问题并有效解决这些问题。

“When there was a need to change the MultiStation in the midst of the monitoring campaign, there were no adverse effects to the project due to a timely and effective response by Leica Geosystems technical support,”said Dr. Tor.

Monitoring solutions by Leica Geosystems support LTA to fulfill its promise and keep the world moving wherever heavy construction projects are underway.