Slope movement monitoring at Hinkley Point C
Case Study
Under construction in Somerset, England, the new Hinkley Point C (HPC) nuclear power station will produce 3.2 GWe of reliable low carbon electricity – enough to power 6 million UK homes. The project goes beyond the supply of low-carbon electricity for around 7% of UK demand. It will bring socio-economic benefits to the region, ranging from increasing local employment to developing a sustainable regional supply chain and advancing new training facilities and qualifications.
HPC’s slope monitoring programme started alongside the Kier BAM joint venture enabling works and constitutes a mixture of an automated total station (ATS) system, inclinometers, extensometers, strain gauges, and piezometers. The monitoring programme collectively monitors vertical slope movement against specific design parameters. The Kier BAM enabling works and the constructed slopes create the foundations for the nuclear power station and the working area to follow contractors. The applied monitoring solution is set to record any slope movement during the construction and operation phase.
处理大型项目
The HPC project scope meant any installed ATS system had to have an integrated optical and GNSS survey control network to transfer fixed control from stable positions to common control prisms within areas expected to see ground movement. A combination of theLeica Geosystems监视解决方案及其分销伙伴SCCS被选为通过经过考虑的调查提供ATS系统。解决方案包括Leica Nova TM50 monitoring total stations通过驱动Leica GeoMoSand supported with theMicroSurvey Star*Net adjustment tool. The system runs every two hours, measuring slope monitoring prisms to the specification of ±1mm. The monitoring results are reported against construction and operational design triggers – accelerated ground movement beyond expected design would enable additional structural ground control measures.
The monitoring programme and the ATS system’s goal is to ensure slope movement performance against design, ultimately ensuring health and safety.
Image 1 (left): TM50 and mounting post, monitoring excavation
图像2（右）：监视系统和控制棱镜的典型设置与发掘作品相邻
Selecting the right equipment
Deciding on a hardware and software provider is all about partnership. For the HPC project, this was a crucial factor. Only a firm, all-encompassing collaboration can satisfy the expected monitoring needs in terms of performance, durability, and reliability.
“Hinkley Point C is located adjacent to the Severn Estuary and is exposed to the Atlantic’s prevailing winds. I needed a product that could withstand these conditions, and I believed Leica as a respected and established brand was a safe selection to meet the project requirements,” said Ben Crossland, Senior Monitoring Surveyor at HPC.
After comparing diverse solutions, available on the market, HPC went for the collective power of Leica Geosystems’ and their distributor SCCS. The reasoning behind the decision was multi-layered – the equipment had to withstand the site’s conditions; the instruments had to perform flawlessly and enable surveyor control network integration. HPC required an “all-inclusive” package, including software, hardware,服务和专业支持，以满足HPC自动化总站系统的自动化需求。
Image3 (left): GNSS/360° prism survey control point
Image 4 (right): ATS with control box, WLAN radio and mounting post
The solution
Leica Nova TM50 monitoring total stations provided durable and precise instruments with the Leica GeoMoS monitoring software. Survey control measurements were processed by SCCS’s bespoke automatic adjustment script, which uses MicroSurvey Star*Net to adjust the ATS control network before every scheduled array slope monitoring measurement cycle. This system provided a fully integrated network, which would help remove the risk of false movement caused by survey control movement. The applied solution consists of the following components:
软件：
- 3倍Leica GeoMoS监视软件
- 1倍Leica GNSS SpiderSoftware
- 1倍Leica Infinitysurvey software
- 1倍Microsurvey STAR*NET调整软件
- 1X SCCS SNASI定制自动化脚本
Hardware:
- 40 xLeica Nova TM50monitoring total stations
- 6 xLeica GMX910GNSS smart antenna
- 25 xLeica GRZ122 prisms
- 2000 GMP104和其他监控棱镜
- 2 xLeica Nova MS60MultiStation
- 1 xLeica LS15digital level
- 1 xLeica Nova TS60total station
- 3 x PC’s with independent power and backup storage
- 46 x Communication and power enclosures with GSM/WLAN radios and solar panels
- 60 x TPS/GNSS/Prism mounting posts (1.2~1.8m tall) & protection enclosures for TPS
Leica LS15数字水平andLeica Nova TS60robotic total station手动用于调查控制和手动监视验证检查，以验证ATS网络正常运行。与这些检查一起，HPC有六个Leica GMX910smart antennas通过Leica GNSS蜘蛛软件进行控制。一个天线坐在一个永久的基站上；其他人在工作区域内分布。天线的位置与Leica GRZ122 prismsto allow the ATS network to use the positions as fixed control. The integration of survey methods allowed real-time position checks to ensure relatively stable positions are not influenced by construction.在阻塞棱镜的地区Leica Nova MS60 MultiStation被用来扫描相关区域。然后将数据进口到Leica Infinity以进行云比较。当自动扫描是在危险区域内安装和维护棱镜的不切实际性，MS60的扫描能力也是在Geomos中使用的。”
“We placed our GNSS systems differentially – one in a stable position (and fixed), the others in relatively stable positions, that are also considered pseudo-fixed. The potential for the positions to move was the reason for including GNSS as part of the solution. In this way, we could ensure unforeseen movement of fixed control positions that we deemed stable, was captured and addressed,” informed Crossland about the technical challenge. “We started with just prisms then realised our reference frame was flexing,so we asked advice from our supplier who helped solve the network stability problems we had by integrating GNSS”.
We needed to trust the equipment and the expert suppliers
“与Leica Geosystems和SCC建立供应伙伴关系的主要好处是工具本身。这是我们信任品牌的地方。另外，它得到了极大的支持，” Crossland总结了他们的经验。“您知道您要支付的费用 - 高质量值得投资。我们对它的运作方式感到满意，并一直期待新的进步。”
Another decisive factor was the aspect of everything working together seamlessly. The interoperability is essential to set up a complex system as the HPC monitoring; thus, the GeoMoS platform combined these multiple data sources into a homogeneous monitoring system. Due to the project’s dynamic nature, the ATS system layout changed weekly. The company always strived to optimise the operation as new working zones open/close and improve the monitoring process to keep the workforce safe.
Customising the solution
Complex projects require the equipment/software provider to understand the customer’s needs thoroughly and always offer suggestions leading towards the optimal solution. The partnership went beyond the mere software/hardware support – with cooperation in operation plan optimisation, and custom builds related to the communication network (e.g., WLAN spanning the entire project).
图像5：典型的深度开挖，用喷涂的混凝土壁板和岩石锚螺栓固定在碎石中，并由岩土仪器和各种大地棱镜和阵列具有自动化的TM50，以确保工人在深处挖掘中的安全性。
It’s all about the data
Every two hours, every day of the year, fully automatically, GeoMoS completes scheduled tasks to instruct the ATS system to collect a series of measurements to compute and update the ATS positions. Once updated, they then measured slope monitoring prisms and computed any deformation. The prism’s movement against a baseline is reported in GeoMoS and automatically sent to our client’s viewing portal MissionOS. Maxwell Geosystems Mission OS combines all HPC monitoring data, survey prism data, inclinometers, strain gauges, piezometers and extensometers. All monitoring data is reviewed through a daily section review group, where movement against construction and operational triggers is assessed. GMX910 data is received in GeoMoS on an hourly basis, which is averaged every 24 hours to enhance data stability, reliability and accuracy from the GNSS. The GMX910-processed average results are used in Star*Net integrated with the ATS network measurements to enable verification of all systems.
A recommendation
坡度监控项目完成后，将库存工具分配给其他领域，尤其是那些面临和打击视线问题的领域，通常是由建筑计划引起的。
“我可以很容易地建议徕卡呈规则的产品。bob综合app下载They are very transparent – I like to look into the GeoMoS system data, understand how the system operates, integrating the fine detail of observation and computation. The open access to raw data and log files was especially useful for a surveyor, so I understood how and why my system operated. I’ve used other products in the past which were supplied by 3路parties and missed that same transparency where you could drill down into specifics of measurement and the data behind it,” Crossland concludes.
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