Dormer Construction

Water Dam Construction

September, 2015

Water Dam Construction> Survey > Design > Consent > Construct

We offer a full package! Email Pete Dormer or 0274 381 221

Download Water Dam Construction Brochure

CPIT R BLOCK FOUNDATION EARTHWORKS

August, 2014

SCOPE

Dormer Construction were pleased to extend their services to be involved in the re-development of the recreational block for Christchurch Polytechnic Institute of Technology. Dormers scope involved the excavation and stockpiling of upper two meters of soil (6,000m3) beneath the proposed building footprint. Dormer managed the removal from site, to an approved facility, of an area of contaminated soil identified during excavation. Dormer assisted in the cement stabilisation of the soil layer using its 47T excavator.  Following the cement stabilisation, the upper layer of excavated soil was replaced and re-compacted including two layers of biaxial geo-grid.

A high level of quality assurance was maintained using nuclear Densometer to ensure compaction to 95 percent of maximum dry density was achieved. These earthworks prepared the site for the construction of a new state-of-the-art gymnasium and all indoor sport campus.

PERFORMANCE

Environment

All works were carried out with very strict sediment control requirements. Managed removal of contaminated material in accordance with local authority requirements.

Health and Safety

No significant incidents or any near misses were recorded across 5,400 man hours.

Programme

Achieved programme in compliance with main contractor construction programme.

Cost/Budget

Measure and value. Approved variations.

Mt Beautiful Wine Earth Dams

August, 2014

SCOPE

Making use of a natural valley watercourse, and storm water capture, Mt Beautiful resolved to create two low-height, low-capacity earth dams to service irrigation needs across significant areas of vineyards and grape varieties. Dormer assisted the site developer with design input for the concrete spillway and embankment proposals.  The large spillway was formed to take a base flow along with capacity to convey a 1% AEP*. This spillway was partially lined with concrete (to convey a 5% AEP) with erosion matting outside of this area for the larger flows. Topsoil was stockpiled and placed over the dam embankment upon completion and used to ease contours.  This agricultural  bulk earthworks scope included; stripping of site topsoil from cut and fill areas, excavation of cut material and cart to fill areas, proof rolling base and undercutting weak material, compaction of earth-fill, placement of topsoil, placement of wave armouring and grading.  Old watercourses within the valley floor were dug out to clean material.  The borrow for the fill was from a gravel colluvium bank adjacent the dam site. The bank was cut back vertically (as had been in the past). During the construction a siltstone was uncovered and this was used for the core of the dams as the permeability of this material was low.  Two dams were formed by Dormer. Dam 1  being 145m long 4.5m high 30m wide consisted of 14000m3 of earth moved during the preparation and building of the dam. Dam 2 112m long x 3.5m high x 24m wide consisted of 15000m3 of earth moved during the preparation and building of the dam.

PERFORMANCE

Environment

Works were carried out in accordance with the requirements of NZS4431 and NZS4402. Achieved compliance with ECcan requirements.  Silt and sediment controls installed.

Health and Safety

No accidents during this contract.

Programme

Works were subject to rigorous field tests (maximum dry density) and site quality inspections recorded by Dormers engaged Engineer.  Achieved 8 week physical works construction programme.

Cost/Budget

Negotiated contract.  Maintained Cost Plan.

EAST RANGIORA STORMWATER

August, 2014

SCOPE

A two-stage project for the construction and commissioning of a storm water attenuation and treatment system. The project involved the formation of a 340m long by 40m wide retention pond that was lined with a geo synthetic liner (GCL). This was constructed within an area where the water table was at or near ground level, positive water pressure existing. Works included bulk earthworks and shaping, tapping into existing natural springs, box culvert road crossings, construction of a new creek for fresh water crayfish, planting for future reserve. Stage 1 was the detention of the basin to separate the storm water flow from the natural ground water. This was in order to provide both retention and treatment of the storm water flows to project the spring feed receiving water bodies. Stage 2 was a broad open grassed water course to direct storm water from the end of the council pipes systems to the stage 1 detention basin.

PERFORMANCE

Environment

All works were carried out with very strict sediment control requirements (to protect adjacent native crayfish environments) and extensive global dewatering of the site.

Health and Safety

No significant incidents or any near misses were recorded across 5,400 man hours.

Programme

Dormer Construction Ltd’s work was interrupted (with consent from Council) when it involved itself in emergency works directly relating to the Canterbury Earthquakes. Delays experienced due to design failure were collaboratively resolved between all project participants.

Cost/Budget

Value and measure. Approved variations.