Slope movement monitoring at Hinkley Point C

Author:Steve Thurgood

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.

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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 monitoring solutionand its distribution partnerSCCS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
Image 2 (right): Typical setup of a monitoring system and control prism adjacent to excavation works

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选择合适的设备

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位于Severn河口附近，暴露于大西洋流行的风。我需要一种可以承受这些条件的产品，并且我认为莱卡是一个受人尊敬的既定品牌，这是一个安全的选择，可以满足项目要求。” HPC高级监测测量师Ben Crossland说。

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,service and specialist support to meet HPC’s automated total station systems’ needs.

Image3 (left): GNSS/360° prism survey control point
图片4（右）：带有控制盒，WLAN收音机和安装帖子的ATS

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The solution

Leica Nova TM50监视总站使用Leica 亚博5分钟快三Geomos监视软件提供了耐用和精确的仪器。通过SCCS的定制自动调整脚本处理调查控制测量值，该脚本使用MicroSurvey Star*NET来调整ATS控制网络，然后再进行每个计划的阵列坡度监视测量周期。该系统提供了一个完全集成的网络，这将有助于消除由调查控制运动引起的错误运动的风险。应用解决方案由以下组件组成：

软件:

• 3xLeica GeomosMonitor software
• 1xLeica GNSS Spider软件
• 1xLeica Infinitysurvey software
• 1xMicrosurvey STAR*NETadjustment software
• 1x SCCS SNASI bespoke automation scripting

Hardware:

• 40 xLeica Nova TM50monitoring total stations
• 6 xLeica GMX910GNSS智能天线
• 25 xLeica Grz122棱镜
• 2000 GMP104 and other monitoring prisms
• 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与GSM通信和电力附件/ WLAN radios and solar panels
• 60 x TPS/GNSS/Prism mounting posts (1.2~1.8m tall) & protection enclosures for TPS

Leica LS15 digital levelandLeica Nova TS60 robotic total stationare used manually for survey control and manual monitoring verification checks to validate the ATS network was operating correctly. Together with these checks, HPC had sixLeica GMX910 smart antennascontrolled through Leica GNSS Spider software. One antenna sat on a permanent base station; the others were spread out within the work area. The antennas’ positions were co-located withLeica Grz122棱镜to 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.In areas where prisms were obstructed, aLeica Nova MS60 MultiStationwas used to scan the relevant zones. The data was then imported to Leica Infinity for cloud comparison. The MS60’s scanning ability was also used within GeoMoS when automated scanning was a preferred option due to impracticality of installing and maintaining prisms in dangerous areas.”

“我们将GNSS系统差异化 - 一个在稳定的位置（和固定），其他位置相对稳定的位置，也被认为是伪造的。位置移动的潜力是将GNSS作为解决方案的一部分的原因。通过这种方式，我们可以确保我们认为稳定，捕获和解决的固定控制位置的不可预见的运动。” Crossland通知技术挑战。“我们从棱镜开始，然后意识到我们的参考框架正在弯曲，so we asked advice from our supplier who helped solve the network stability problems we had by integrating GNSS”.

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我们需要信任设备和专家供应商

“The main benefit of engaging in a supply partnership with Leica Geosystems and SCCS are the instruments themselves. This is where we trust the brand. Plus, it comes with great support,” Crossland summarised their experience. “You know what you paid for – the high quality is worth the investment. We are satisfied with how it works and are always eagerly expecting new advancements.”

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.

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Customising the solution

复杂的项目要求设备/软件提供商彻底了解客户的需求，并始终为最佳解决方案提供建议。合作伙伴关系超出了单纯的软件/硬件支持 - 在操作计划优化方面的合作以及与通信网络相关的自定义构建（例如，WLAN跨越整个项目）。

Image 5: Typical deep excavation into fractured rock held by sprayed concrete facades with rock anchor bolts, monitored by geotechnical instrumentation and arrays of geodetic prisms with an automated TM50 to ensure the safety of workers in and adjacent to deep excavations.

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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.

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A recommendation

Once the slope monitoring project is completed, the stock instruments are assigned to other areas, especially those facing and combating line-of-sight issues, generally caused by construction programmes.

“我可以轻松推荐Leica Geosystems产品。亚搏彩票手机版下载它们非常透明 - 我喜欢研究Geomos系统数据，了解系统的运行方式，并整合了观察和计算的细节。对原始数据和日志文件的开放访问对于测量师特别有用，因此我了解系统如何以及为什么操作。我过去曾使用过其他产品3亚搏彩票手机版下载^rd党派和错过了相同的透明度，您可以深入研究测量的细节及其背后的数据。” Crossland总结道。

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