Service shelf one
Retaining Wall Design
We design cantilever walls, counterfort walls, gabion structures, deadman anchored walls and hybrid systems where a single type will not suit the site. The starting point is the design basis: soil layers and strength parameters, the groundwater condition, the surcharge above the wall and the movement the structure above can tolerate. Those four items are agreed and written down before geometry begins, because a wall that is later asked to carry an unplanned driveway or a pool deck has to be rechecked from the same foundation.
Geometry follows the checks. We run the external stability set, the internal bending and shear checks, the sliding and overturning margins and the bearing pressure against the footing. Where anchors carry part of the load, the anchor schedule is developed in parallel with the wall stem so that plate locations, reinforcement congestion and cone pullout do not conflict. Drawings include the wall elevation, the typical sections, the anchor and reinforcement schedules, the drainage detail and the sequence of construction, with the sequence set out in plain language rather than a single note.
Residential work is a large part of the practice. Tight lots mean the excavator has one angle of approach, spoil must go somewhere, and anchors cannot reach into a neighbouring property without a legal agreement. We mark those constraints on the drawing instead of leaving them to the contractor to discover, and we issue alternates where access makes the primary detail impractical. The result is a wall that can be priced accurately and built without a field redesign.
Service shelf two
Soil Anchor Systems
Anchors are only as good as the bond they develop in the ground, so our anchor design begins with the soil, not the steel. We select between grouted tiebacks, soil nails, helical anchors, deadman arrangements and rock bolts, and we state the bond length, the grout pressure, the proof load and the lock-off load for each type. The failure surface is modelled behind the wall face so that the bond zone sits beyond the active wedge, and where a report gives a range rather than a number we design to the low end and call for staged testing.
Corrosion protection is treated as part of the anchor, not an accessory. The specification names the encapsulation, the centralisers, the trumpet and the head protection for each exposure class, and it says which components are inspected before grouting. Temporary anchors that will remain in the ground are identified as permanent in the design file, so a future owner is not left guessing whether the steel is protected.
Anchor layout is developed with the contractor in mind. We check that the drill rig can reach each anchor head, that the plate bearing area fits the wall face without clashing with reinforcement, and that the test jack can be mounted at the angle specified. When the ground is erratic, we design a test program with staged lengths rather than a single uniform length, so that the first few anchors become information for the rest of the wall. This costs a little more at the start and usually saves more than it costs.
Service shelf three
Slope Stabilization
Slope movement is a signal, and our first job is to read it correctly. We examine the tension cracks, the toe bulging and the water paths, and we ask what changed: a new cut, a cleared tree line, a leaking irrigation line, a road widened at the crest. The answer shapes the scheme far more than any generic stabilization detail, because regrading the crest and fixing a leaking pipe may arrest a slide that would otherwise have been anchored at the toe.
Where structural stabilization is needed, we combine methods. Subsurface drainage lowers pore pressure behind the slip surface. Anchored beams or soil nails provide restraint through the moving mass into stable ground. Buttress fill adds weight at the toe where there is room. Surface protection controls erosion and prevents the next season of rainfall from recharging the cracks. The combination is chosen against the actual mechanism, and the design report shows the margin before and after each measure so that the client can see which elements carry the most benefit.
Monitoring is part of every stabilization project we design. Surface pins, inclinometers or crack gauges are set before construction and read at a fixed interval, and the readings are compared with the movement rates the design assumed. If the slope moves faster than predicted, the next stage is adjusted rather than pushed ahead. Ownership of the slope above and below the site is checked early, because a scheme that requires work on a neighbour parcel needs an agreement long before the equipment arrives.
Service shelf four
Foundation Assessments
Existing buildings are asked to carry new loads all the time: a second storey, a heavy workshop machine, a retail conversion with a mezzanine. The question is not whether the concrete looks sound but whether the soil beneath it can take the increase without settlement that the structure cannot tolerate. Our assessment combines a review of the original drawings, a site inspection of the footing and the surrounding grade, and a bearing check against the geotechnical information available for the area, supplemented by targeted investigation where the record is thin.
We report the current condition, the allowable increase and the settlement estimate in the same document. Where the footing is sound but the soil is marginal, we describe the options: load spreading, a wider pad, micropiles, ground improvement or a limit on the new load. Each option carries an approximate cost implication and a monitoring requirement, so the decision is a comparison rather than a yes or no.
Foundation work also covers distress investigations. Diagonal cracks in a basement wall, a slab with a hollow spot, a door that no longer closes cleanly, or a corner of the house that has dropped all point to a mechanism that should be identified before a repair is chosen. A repair that addresses the symptom and not the cause will usually be repeated, and our reports are written to prevent that repetition.
Service shelf five
Drainage Corrections
Most retaining wall distress we inspect involves water. A blocked weep hole, a failed filter fabric, a roof downspout discharging at the wall face or a surface that now slopes toward the wall instead of away can raise the pressure behind a wall by a large margin against its design assumption. The correction is rarely a single pipe; it is a system that collects, filters and carries water to a legal outlet.
We design the collector behind the wall face, the filter envelope that prevents fines from entering and clogging the drain, the outlet through the wall or around the end, and the surface grading that keeps rain from ponding at the top. Where a wall has failed drainage, we map the existing outlets, prove which ones are running, and specify remedial work that can be completed without destabilizing the wall. The work is sequenced so the wall is never left with a long open excavation at its face.
We also review grading at the site scale. A wall that receives runoff from an uphill neighbour needs an interception system at the property line, not only a drain at its own face. Surface flow paths are traced on a plan and discussed with the owner, because a drainage design that ignores the catchment above the site will fail in the first significant storm regardless of how well it is built.
Service shelf six
Load Testing and Reports
Design values are claims until a test confirms them. Our load testing service covers anchor proof tests, performance tests and evaluation tests, along with load tests on piles or foundation elements where the scope requires. We specify the test load, the hold period, the acceptance criteria and the instrumentation, and we attend the test so that the readings are witnessed rather than forwarded.
Dial gauge and load cell readings are recorded at each load step and compared with the elastic and residual movement limits set in the specification. Where a test meets the criteria, the report records the result and the lock-off load. Where it does not, the report states the shortfall, the likely cause and the remedial option, whether that is a longer bond, a re-test at a reduced load or a supplementary anchor. We do not smooth over a marginal result; a marginal result is exactly what a reviewer needs to see.
Reports are issued as a complete file: the design basis, the test schedule, the field records, the readings, the photographs and the as-built deviations. Every reading is traceable to a date, a location and an instrument, and the file is structured so that an inspector who was not present can follow the chain of evidence. This discipline costs some time on each project and saves much more when a wall is sold, refinanced or inspected years later.