Foundation and field engineering
Foundation engineering even in confined spaces
In Finland, foundation engineering is often challenging due to varying base conditions. Bedrock areas and weak soils vary frequently. All road projects usually involve quarrying, embankment fills, soil replacements and pile driving, which Destia implements according to plans.
Almost all infrastructure projects comprise quarrying, filling in embankments, replacement of materials and piling. Destia’s professionals possess competence in designing projects which involve demanding foundation engineering as well as working next to existing structures or in other confined spaces.
Our foundation engineering services cover excavation supports, foundation work, concrete construction work, piling, underpinning and foundation repairs, including load transfer structures.
Destia's professionals have extensive expertise in sheet pile walls, soldier pile and lagging walls, and bored pile retaining walls with horizontal beams, anchors and fixing bolts. Together with our partners, we can also arrange construction and excavation work on the site.
Destia exploits the most recent technologies introduced in the field, for example machine automation. Earth construction machines are controlled using the most accurate GPS positioning and control system with digital 3D-model design. Machine automation improves the efficiency and quality of the work: surveying information is available all over the structural layers and cuttings under construction.
Piling is a foundation engineering method that is used when the ground is not supportive enough for construction purposes. Piles transfer the load from structures through the soft layers down to a solid base. Piling can also be used for repairing and strengthening existing foundations, for example when a building is extended and additional load on the foundation is created. The piling techniques Destia offers include pile driving, bored piling and jet grouting. Our comprehensive machinery and equipment also enable piling inside buildings and in other tight spaces.
Piling is our core expertise, so you can rely on our uncompromising professionalism.
Steel tube piling – Precast concrete piling - is an ideal foundation solution for all types of buildings and structures. The advantages of steel piling over concrete piling include low vibration and less risk of damage to the piles in rocky soil. We install steel piles in all sizes by driving or drilling. Concrete piling in turn can be a more cost effective solution in the right conditions.
We install both steel and concrete piles using hydraulic and pneumatic hammers. In restricted access areas and in close proximity to buildings, hydraulic and pneumatic hammers are generally used to minimise the effects of vibration. The load-bearing capacity of driven piles can be checked by taking PDA measurements.
Bored piling is a precision technique that allows piles to be installed through multiple layers and boulders all the way down to the solid bedrock. Our product assortment includes all the pipe piles, steel core piles and bored injection piles that can be installed using the bored piling technique. We typically use RD pipe piles and Titan Ischebeck or MAI bored injection piles that are self drilling. Bored injection piles can also be used as friction piles in suitable soil conditions, in which case the piles are shorter than in load-bearing applications.
The jet piling/grouting technique is used to create piles directly in the soil by injecting a concrete and water solution under high pressure through nozzles in the drilling equipment at the same time that the drill pipe is rotated and lifted. The diameter of the pile can be adjusted by varying the diameter of the jet nozzles, the pressure, the rotating speed of the drilling equipment and the speed that the drill pile is lifted. The jet piling technique can also be used to create sealing walls, for example at the bottom of sheet pile walls.
Grouting seals and reinforces structures to make them durable. Grouting is the technique of pumping a liquid hardening substance, such as cement, urethane, sodium silicate or epoxy, into the ground, bedrock or a concrete structure in order to seal or reinforce the structure.
Grouting significantly increases the lifespan and reliability of these structures. Typical applications include dams, bridges, canals, various piles and beams, and tunnel structures. Grouting also enables precision repairs to be made, often without having to close the site.
Destia has extensive experience in grouting. Our services cover both chemical grouting (including epoxy, urethane and sodium silicate) and cement grouting (including regular and quick-setting cements, as well as various micro cements). Epoxy grouting is typically used in concrete structures and machine foundations, urethane grouting for soil and bedrock structures, and cement grouting for various kinds of soil grouting and rock spaces, such as in tunnels. In addition, we use jet grouting for securing the lower edges of sheet pile walls.
Our comprehensive grouting machinery and equipment can be used for repairing small cracks and leaks, as well as for massive grouting projects, such as repairing dams. By using our own drilling equipment, we can also carry out any drilling that is required by the grouting projects and install the grouting pipes. Our comprehensive drilling equipment can also be used to perform grouting directly without leaving any pipes in the ground.
Anchoring stabilises structures. Anchoring ensures that structures remain in place both during construction and permanently according to the individual demands of each project. Typical structures that are anchored during construction include the retaining walls in excavations. For example, surrounding streets and buildings must be stabilised with tie-back anchored retaining walls whenever a construction pit is opened nearby. The anchor forces are directed either into the ground or into the bedrock depending on the foundation conditions in the construction site. Permanent anchors in turn remain part of the final structure, so their lifespan and corrosion requirements must be compatible with all other parts of the structure.
Destia has extensive expertise in anchoring and can perform all permanent and temporary anchoring jobs in excavation, bedrock, soil and foundation projects. We use both wire and rod anchors from leading brands, such as Gewi, Dywidag, Mac Alloy, SAH, Ischebeck Titan and MAI.
Our comprehensive machinery and equipment allow us to install anchors of all sizes and in all conditions, including in tight spaces. Together with the anchoring work we perform all the necessary water pressure tests, grouting, open drilling and tensioning with our own machinery and equipment all the way up to 5000 kN.
One of our special contracting services is sheet piling using a high-frequency vibrator. Variable frequency hammers enable sheet piling in the immediate vicinity of existing foundations and structures without damaging them.
The machinery and equipment we use also enable sheet piling in challenging ground conditions and without limitations to the size and length of the sheet piles.
The high-frequency vibrator enables the sheet piles to be installed and removed with less wear compared to other techniques. This increases the number of times the sheet piles can be reused, while reducing the amount of maintenance and repairs.
The procurement of sheet piles is always agreed separately together with the client, and we can assist in the procurement or rental of sheet piles and other retaining wall components if required. We can also install entire sheet pile walls on a turnkey basis, in which case the delivery includes sheet piling, the installation of anchors and iron structures (including horizontal beams and anchor casings), and jet grouting to secure the lower edge of the sheet pile walls.
Shotcreting is a technique in which concrete is projected at high velocity into the desired area instead of casting the concrete. Shotcreting is used for repairing concrete and brick structures, as well as for reinforcing rock structures. It can also be used to reinforce foundations. The advantages of shotcreting include the ease with which masses of concrete can be applied and the minimal need for concrete moulds.
We often carry out shotcreting projects on a turnkey basis when requested by the client. In these cases the solution we provide includes preparing the structures (such as scaling, chiselling or sandblasting) and performing all the required reinforcements, mould making and guide work. Our services also include shotcreting surface treatments, such as shearing and coating.
Our comprehensive machinery and equipment can be used to professionally implement almost all kinds and sizes of shotcreting projects. Over the years we have served our clients in a wide range of projects, from small concrete repairs and shotcreting earthfills and retaining walls to the large-scale shotcreting of rock structures. Our satisfied clients show their gratitude by coming back to us for new construction projects.
Our shotcreting services include both dry and wet mix methods. Dry shotcreting is performed by hand, while wet shotcreting is generally performed as a mechanised procedure.
Dry shotcreting: in the dry mix method, a pre-moistened concrete mix is conveyed pneumatically through a hose onto the target. If required, water can be added to the concrete mix only at the end of the hose. This method is suitable for repairing structures that are complex or located in tight or hard to reach places. Typical applications include rock shafts, embankments, reinforcing foundation structures and repairing concrete structures.
Wet shotcreting: in the wet mix method, previously prepared concrete is pumped through a nozzle onto the target without adding any more water. This method is suitable for projects that require large volumes efficiently, for example when reinforcing the walls of rock tunnels.