DELIVERING EARLY
Earthworks and civil engineering contractor MJ Church has combined its holistic, model-driven approach to complex infrastructure projects with an integrated Trimble ecosystem of hardware and software – all hosted within Trimble Connect’s common data environment.
Scheduled to finish in 2026, this project is being delivered by Hampshire County Council, working closely with National Highways appointed main contractor VolkerFitzpatrick and MJ Church.
The design of the M27 Junction 10 improvement scheme, which includes a new motorway underpass and three new slip roads to support the new Welborne Garden Village, was determined by National Highways’ decision to adopt the box slide construction technique for the underpass. This approach required the excavation of approximately 22,000m3 of clay and chalk to create a safe working void for the installation of the 8,500-tonne reinforced concrete underpass structure via hydraulic jacking.
The nine-day possession of this eight-lane section of the strategic road network meant that contractors had to - no margin for error – a challenge that placed a strong emphasis on planning, collaboration and data accuracy.
Key to the precision and efficiency with which this section of the works was successfully executed was MJ Church’s digital-centric approach. Responsible for all the model’s updates and the survey, volumes and drone data used to refine it, the constant flow of information between site and office was seen as a vital aspect in establishing the model as a single source of truth.
This was established with Trimble Connect as the common data environment (CDE) for the project.
The complexity of the project presented significant preconstruction challenges: How can we prove that the box slide will be successful? How can we demonstrate this approach to the client and stakeholders and win their confidence? Is this actually buildable? And, more specifically during the works, how can we ensure that the skilled machine operators have a full understanding of the data they are working with? Is the survey correct? Are we confident in the expected volumes and therefore achievable outputs?
A start-of-shift briefing.
Can we fit these machines into this space safely and what plant is suitable for that width? MJ Church’s answer to these questions was to fully model the construction phases in Trimble Business Center (TBC) software.
All survey data, including the original topo survey, along with inputs from other sources such as its DJI Mavic 3 Enterprise drone, was imported into this platform.
Working collaboratively with VolkerFitzpatrick, the initial linework Civil 3D model was taken and transformed into something from which the machine operators could derive real utility, refining it over six iterative versions into a highly detailed, risk-mitigating end result.
This model served every stakeholder and provided the essential foundation for the digital rehearsals conducted ahead of the 19-phase excavation.
True to MJ Church’s ethos of geospatial data democratisation, the model was transformed in TBC from initial outline design into a holistic tangible model that was accessible, communicable and usable by every stakeholder.
Trimble Business Center software’s ability to process and model geospatial data was used to ensure each of the models created for the works, including the advanced offline earthworks, controlled possession excavation and multimaterial backfill operations, were developed with the specific needs of the machine operators in mind.
Trimble Business Center used to create the 3D model.
Extensive detail was used, including colourisation, text, slope lines and easy hosting of the 3D IFC file for the box to interrogate the model relatively. Time was also spent on simple details such as making the boffom of the bench green and the slant of the bench grey for easy identification.
The high quality of the models generated in TBC resulted in excellent feedback from downstream users, with the 3D engine proving invaluable for interrogating and manipulating all types of geospatial data in full 3D alongside other assets. The drag-and-drop environment means when a client sends an IFC file of the structure, it can be dropped in.
If it is a point cloud collected from the drone, that also goes in without any hassle.
The completeness of the 3D model enabled the team to preempt problems and optimise the design ahead of the works. In one example anticipating undesirable weather, alterations were made to the model to introduce a 1.5% longitudinal fall into the benching excavation, allowing the rainwater to be managed towards pumps if required.
In another example, TBC’s corridor tools were used to create the H:1.50m x V:1.0m benching geometry. These tools allowed the work in progress model to remain dynamic and easily editable as the planned design was collaboratively optimised in consideration to other constraints.
A separate corridor was created for the east and west benches, and it was quickly identified that the benches could not run parallel with the formation excavation due to the varying elevation on the expected clay and chalk strata and the interface with the 70° sidewall at the base of the excavation. Thus, the azimuth direction was skewed independently on each side to optimise the intersect line. This reduced the excavation volume required under possession as much as possible.
Trimble SiteVision was used for for enhanced on-site visualisation, clash detection and decision support.
Throughout the project, it was important to have a single source of truth where everyone can view, share and access project information from anywhere, at any time. Central to this process was Trimble Connect as the host for the model and all the geospatial data, which removed the irritating process of constantly asking ‘which model… is it this one?’ whilst looking at it through somebody else’s Teams or a native software that simply couldn’t bring the data to life.
The approach was to be as transparent as possible, all agreeing from the same source in the same environment, creating practical BIM without the unnecessary bloat.
Handling over 45–60 file formats (including IFC, DWG, PDF, point clouds, geospatial data and Trimble-specific formats), and with strong 3D viewing capabilities, Trimble Connect served two clear functions on this project; firstly, as a folder structure for the Trimble Access field/survey software to dial into and pull data across and secondly, as a collaborative CDE for planning and hosting the digital rehearsal process which was a significant element in the project’s success.
Trimble Connect enabled a smooth flow of information across the Trimble eco system, which included:
- The R980 GNSS rover used for checking the control network, setting out, grade checking and recording as-built. These GNSS rovers and on-machine MS976 receivers were selected for dependability and in particular, the ProPoint technology. ProPoint brought robust performance on a site with many potential degradation issues such as moving machines and working in an excavation up to 10m in depth.
- R750 Base Station, which served RTK corrections to both the GNSS rovers, UAV platforms and machine control systems via UHF radio and NTRIP in an RTCM formation to increase compatibility.
- Earthworks Machine Control and WorksManager software for centimetre-level accuracy in excavation, grading and material placement.
- SiteVision mixed reality technology for enhanced on-site visualisation, clash detection and decision support, turning a complex piece of work into something tangible and rapidly increasing understanding of the project for those not present full-time.
- Business Center for processing field data, model refinement, surface generation, volumetric quantification and quality assurance.
- Access field survey software and TSC7 Logger for synching with the model via Connect. If a change is made in the office, it efficiently propagates down to the site team eliminating setting out errors emanating from potentially incorrect file revisions – no need for USB sticks.
MJ Church also used a KOREC-supplied DJI Mavic 3 Enterprise drone and Soarvo data sharing and handling cloud software. Together, they provided an additional highly visual aspect of the planning and checking process by bringing the scale to life and assisting with material planning movements. In Teams meetings, Soarvo could be used to spin the whole 3D model to explain plant access, stockpile locations, etc.
3D Connect model showing +0.50m clay surcharge & 1in1 final profile protection slopes prior to final trim.
At MJ Church, the digital rehearsal begins before any ground is broken. Using the detailed 3D models the company brought together operators, engineers and supervisors for virtual walkthroughs ahead of the day’s planned activities. Each session was based on an extensive handbook that clearly defined the construction sequence, eliminating any ambiguity around the design and its implementation.
These start-of-shift briefings provide essential clarification of the planned work while reinforcing all health, safety and environmental considerations, ensuring no confusion arises during high-pressure operations. Above all, they served to de-risk the activity from three key perspectives: planning, personnel and geometry.
Following the nine-day Christmas possession, the M27 Junction 10 project was completed successfully a day ahead of an extremely tight schedule. The high level of detail invested by MJ Church in its digital-centric approach was a strong factor in this achievement.
Creating an environment where everyone is involved in the model paid dividends. All stakeholders gained clarity and full understanding of these complex works, which contributed greatly to the success of the operation. MJ Church is continuing this approach onto one of its next projects on the A47 Thickthorn Junction scheme in Norwich.