Quarrying (Aggregates)

With approximately 1,300 quarries in the UK producing between them, c 300 million tonnes aggregates for the construction industry each year, along with over 50 million tonnes of ‘quarry fines’ and over 20 million tonnes of ‘quarry waste’, GWP has much to offer the UK quarrying industry.

Quarrying and opencast mining is one of the cornerstones of GWP’s work. GWP has over 30 years’ UK and international experience in quarry design at every stage of the process from resource evaluation and feasibility studies through preparation of documentation supporting planning applications to detailed quarry phasing plans that can be implemented and used for monitoring and management purposes.

We maintain all of the primary quarry design skills in-house and have a strong network of environmental, legal and financial specialists with whom we work closely on a regular basis.

GWP has a wide range of skills which are used within this sector.

Geological investigation and modelling: desk study, SI design, supervision and resource modelling.
Resource evaluation: resource and reserve evaluations.
Quarry design: including geotechnics, phasing and restoration.
Groundwater: assessment and management.
Surfacewater: assessment and management.
Blast design and optimisation: characterisation of rockmasses, blast design, vibration and air-overpressure monitoring.
Topographic surveying: by GPS, robotic, targetless and UAV.
Training: for face workers, foremen and managers.

Geological investigation and modelling

Desk studies are carried out to provide a comprehensive understanding of an area’s geological, geotechnical and hydrogeological regimes.

These studies may include:

reviews of published literature and historical maps;
previous site investigation work;
remotely sensed data;
land use searches; and
services searches.

This information is used to design effective site investigation programmes, to prepare data packages for marketing reviews and for the selection of mineral exploration areas.

Site investigations are conducted to acquire data for mineral exploration, resource evaluation and construction projects. GWP has extensive experience in the design, implementation and supervision of site investigation programmes, including:

geological and geotechnical mapping;
borehole drilling;
trial excavations;
geological and geotechnical logging
in situ testing and sampling;
geotechnical and hydrogeological installations; and
geochemical and geophysical surveys.

Resource Evaluation

Deposition evaulation studies require a detailed understanding of the geology of both the mineral and waste components of a deposit. GWP has wide-ranging experience in this area having carried out resource and reserve evaluations for cement raw materials, bulk minerals, coal, iron ore, and base and precious metal deposits. GWP uses LSS software for volumetric calculations and Datamine for block modelling and the evaluation and visualisation of complex deposits.

Quarry Design

A thorough understanding of the geological regime is the essential foundation for a robust quarry design. GWP excels in the design of large quarries and opencast mines to the highest standards. Our clients are offered a complete service in relation to quarry design, including site evaluation, product appraisal, conceptual and detailed designs, scheduling and phasing of operations, and restoration design.

Geotechnics

Design of excavation, tips, stockpiles and lagoons and the production of reports as required by the UK Quarries Regulations (1999). The Practice has designed tips comprising many millions of cubic metres and up to 100m high. Internal tip drainage measures are incorporated into the design where construction rates are high and permeability low.

Rock mass characterisation and diggability assessment for tunnel, face and blast design, block size distribution and to determine whether blasting is required.

Rockfall hazard, risk analysis and rockfall containment design, including rapid slope assessment to rank areas of greatest potential danger and predictive rockfall trajectory analysis to size containment measures such as fences, ditches etc.

Stability analysis to demonstrate the security of proposed operations or back-analysis of failures. For many assessments conventional limit equilibrium anaylsis using Rocscience's Slide is suitable. However, if further analysis is required numerical modelling can be undertaken using FLAC Finite Difference program, UDEC, a Distinct Element method, or Rocscience's Phase2 Finite Element method for rock and soil applications.

Phasing

A phased working and restoration scheme is to demonstrate that the site can be taken from its current state to the proposed end state and describe exactly how that will be achieved.

There are three reasons why this is important:

To demonstrate to the operator that the proposed scheme is feasible and can be implementedsafely and economically;

To provide the environmental assessment team with the information they need to model impacts at critical stages throughout the operational life of the quarry;

To explain to the MPA, consultees and all other stakeholders how the operation will unfold during its life and underpin environmental impact assessments.

Restoration/Afteruse

GWP Consultants has extensive experience in designing quarry restoration for a range of after-uses. We produce buildable designs that give rise to final restoration landforms that are compatible with the surrounding landscape and with sympathetic after-use in mind.

Design is necessarily an inter-disciplinary process and generally requires close and interactive working relationships with other specialists. We have a well developed network of other specialist firms with whom we collaborate on a regular basis to deliver a complete service to clients.

Groundwater

GWP Consultants has more than 35 years of investigating, assessing and designing mine and quarry water management schemes and their impacts on the water environment. This
experience covers hard rock quarries, sand and gravel pits, and highly permeable limestone quarries throughout the UK, Europe and further afield.

We have a specialist team of hydrogeologists and hydrologists, supported by geologists, geotechnical engineers, quarry designers and land surveyors, who routinely assess

de-watering requirements and impacts;
design de-watering systems; and
mitigation measures to protect groundwater receptors (private and public bores and wells, eco-systems and water bodies, as well as built infrastructure) from level and flow derogation and/or water quality deterioration.

Our work routinely includes:

desk studies and water features surveys;
ground investigations (boreholes and piezometers installations);
single bore permeability testing (variable head tests, packer tests);
multiple bore pumping tests (step tests, constant rate tests, constant drawdown tests);
spring and stream flow gauging;
rain gauge and weather station installation; and
water quality sampling and testing.

We have a suite of analytical and numerical modelling software codes for data analysis, aquifer simulation and de-watering prediction, run-off and attenuation facility design.

Surface Water

Surface water management plans are becoming increasingly more commonplace within the UK, predominantly associated with Environmental Planning and Permitting
legislation. Surface water management aims to provide an assessment of flood risk and hydrological impact, whilst identifying appropriate mitigation methods, in line
with current regulations.

Blast Design and Optimisation

GWP has experienced geotechnical and blasting engineers with extensive expertise in the characterisation of rockmasses, blast design, vibration and air-overpressure monitoring, Environmental Impact Assessments and in drilling and blasting optimisation. Expertise in these specialist areas compliments other skill areas of quarry design and geotechnics.

Rockmass characterisation and diggibility studie.
Fragmentation studies.
Face profiling.
Audit of drilling and blasting practices.
Blast and vibration Environmental Impact Assessments (EIA).

Topographic Surveying

Our skill areas include:

topographic surveying and setting out;
UAV (unmanned aerial vehicle) drone surveys;
surveying geological and geotechnical features;
setting out and surveying for engineered landfill cells;
computation of volumes (including placed waste).

Face Worker Training

GWP offers on-site Geotechnical training by geotechnical engineers with extensive experience in safe and effective assessment and design of quarries, tips and lagoons throughout the UK and Ireland.

These courses are tailored specifically for particular quarries (hard rock or sand & gravel) and are suitable for quarry managers, foremen, face workers and anyone working at or near quarry faces, tips, lagoons, stockpiles, or old mine workings. The duration can be from a half a day to 2 days and often include time on site to identify and discuss the issues.

Course content can include:

excavated slopes - hard rock, weak rock or sand and gravel;
tips and stockpiles;
lagoons;
haul roads.