Gravity sensing for rail construction feasibility study
Lead Participant:
SILICON MICROGRAVITY LIMITED
Abstract
Identifying subsurface hazards is a critical issue for railway construction. Finding unexpected features during construction can have major cost and time impacts. Similarly, if not identified hazards can cause subsidence and deformation during the life of the track. Subsurface hazards may be man-made such as old minings or tunnels or natural in the form of sinkholes or karsts which can form over time.
Traditional site survey technologies such as ground penetrating radar, electro-magnetics and seismic are used extensively for site surveying but all have limitations. Gravity sensing has long been identified as a measurement which would add significant value to site surveys. Any subsurface feature that has a change in density will create a change in gravity. But until now a commercially viable sensing system has been lacking.
Silicon Microgravity has spent seven years of research and development on MEMS relative gravimeters. A prototype surface system has been successfully tested at the National Buried Infrastructure Facility in 2021 and the commercial prototype will be available at the end of Q1 2023\. This Project is a feasibility study to determine the applicability of gravity surveying to GCRE but also to the wider rail construction industry.
The proposed project will start by working with GCRE to identify potential subsurface hazards at the site and agreeing a set of scenarios. This will involve defining the type of the hazard, the depth, size, and density versus the surrounding material. This data will then be used to forward model the gravity anomaly that the hazard would create. This will then be evaluated versus the projected sensitivity of the SMG gravimeter to determine which hazards can be identified in a real-world scenario. Using the forward modelling, a gravity station survey program will be developed to determine optimal survey station data density for hazard detection over large areas. This will demonstrate the commercial viability of SMG gravity surveys for site surveys at GCRE and more broadly in the rail industry.
Traditional site survey technologies such as ground penetrating radar, electro-magnetics and seismic are used extensively for site surveying but all have limitations. Gravity sensing has long been identified as a measurement which would add significant value to site surveys. Any subsurface feature that has a change in density will create a change in gravity. But until now a commercially viable sensing system has been lacking.
Silicon Microgravity has spent seven years of research and development on MEMS relative gravimeters. A prototype surface system has been successfully tested at the National Buried Infrastructure Facility in 2021 and the commercial prototype will be available at the end of Q1 2023\. This Project is a feasibility study to determine the applicability of gravity surveying to GCRE but also to the wider rail construction industry.
The proposed project will start by working with GCRE to identify potential subsurface hazards at the site and agreeing a set of scenarios. This will involve defining the type of the hazard, the depth, size, and density versus the surrounding material. This data will then be used to forward model the gravity anomaly that the hazard would create. This will then be evaluated versus the projected sensitivity of the SMG gravimeter to determine which hazards can be identified in a real-world scenario. Using the forward modelling, a gravity station survey program will be developed to determine optimal survey station data density for hazard detection over large areas. This will demonstrate the commercial viability of SMG gravity surveys for site surveys at GCRE and more broadly in the rail industry.
Lead Participant | Project Cost | Grant Offer |
|---|---|---|
| SILICON MICROGRAVITY LIMITED | £36,083 | £ 24,897 |
People |
ORCID iD |
| Francis Neill (Project Manager) |