Efficient and economical equipment for ICE
New solutions for big diameter drilling to micro piles and sheet pile installation.

In the changing Indian construction environment, companies are continuously searching for new technologies to enable them to complete their projects more efficiently and through shorter timescales.

The significant progress of the development of more powerful drilling rigs is providing piling companies with an increased number of options for the execution of foundation projects. Today, modern rigs are capable of performing a number of different foundation techniques. This results in specialist equipment being available for a broader spectrum of applications. There are groups of drilling rigs which have become integrated rigs or multi-purpose drill rigs.

This ability provides rig operating companies with alternatives for selecting the techniques best suited for them. Process reliability and economic viability are essential requirements that are central in the selection of drilling techniques and drilling equipment for specialist foundation construction. As a result of the remarkable developments in the area of hydraulics and electronics, drilling rigs are now able to convert the applied energy into drilling capability with the highest degree of efficiency. Processor-controlled computer operations undertake the execution of drilling processes. They guarantee a consistent quality of execution, facilitate continuous process monitoring and effectively relieve the rig operator.

Several examples emphasise and demonstrate this development in the foundation rig industry.

Cased Continuous Flight Auger Technique

The first example is the Cased Continuous Flight Auger Technique (CCFA). It is a further development of the continuous flight auger technique (CFA). With this process, drill casings and a continuous auger are drilled simultaneously into the ground by two independent rotary drives mounted on top of each other.

While the solution with two rotary drives is a very effective but a costly system, a further enhancement of the technique was evaluated. The result was the introduction of a torque multiplier.

The Bauer Torque Multiplier (BTM) is a mechanical unit attached to the cardanic joint below the rotary drive of the BG rig. The rotary drive is turning the auger in clockwise direction, while the BTM is simultaneously turning the casing in counter-clockwise direction.

The ratio is fixed at 1:2, so that the BTM doubles the incoming torque, halves the rotation speed and inverts the direction of rotation of the casing. As with other double rotary system, the spoil exits the top of the casings after a certain depth. To manage and reduce the risk of spoil falling down from big height in an uncontrolled manner, the spoil discharge chute system was developed. When the spoil reaches the top of the casing it enters an oversized collector and then falls through a series of telescoping chutes to the ground in a controlled manner. During the drilling process the chutes are withdrawn to maintain a safe drop height for the spoil.

After reaching the specified design depth, concrete is pumped through the hollow stem of the continuous auger as the auger and the casing is simultaneously withdrawn from the borehole. Reinforcement can be inserted subsequently into the fresh concrete.

Cased continuous flight auger piles are used either as foundation piles or for the construction of secant bored pile retaining walls, for which the verticality of the wall is of paramount importance. The much stiffer drill casings, when compared with the continuous flight auger, enable the borehole to be executed with the necessary degree of verticality.

The conversion of a standard BG drill rig to this drilling mode a relatively straightforward exercise with only additional equipment being added without major alterations to the structure, hydraulics or electrics of a standard BG rig.

Full Displacement Piling system

Another example is the construction of bored piles with the Full Displacement Piling system (FDP).

This technique is characterised primarily by producing no or only a very small amount of spoil when the displacement tool is drilled into the ground. During this process, the drill string consisting of an auger pilot, a starter auger section, a conically tapering displacement body with cylindrical middle section and counter-rotating flight section, is drilled and pushed into the ground. The capability of modern BAUER BG rotary drilling rigs to apply high torque and crowd pressure simultaneously is being used to great advantage with this technique. They are capable of activating torques of up to 400 kNm and crowd forces of up to 330 kN. The crowd pressure is generated via a crowd winch system and is, therefore, available at a constant level over the total travel of the rotary sledge. An auger pilot at the base of the displacement body ensures the tool?s penetration into the ground as well as into the underlying load-bearing horizon. After reaching the specified design depth, concrete is pumped into the bore through the hollow stem of the drill string as the displacement tool is simultaneously withdrawn from the ground. During withdrawal of the drill string, the counter-rotating flight section mounted at the top of the conically tapering displacement body densifies the soil material that has fallen into the bore during the concreting process.

Productivity is primarily dependent on the borehole diameter, the type of soil, its density and displacement capacity and, of course, the drilling rig?s capacity regarding torque and crowd pressure. Depending on the type soil, up to 60 linear meters of finished pile per hour can be produced. The limitations of process are determined by the prevailing subsoil conditions. Non-displaceable soils, such as dense sands and gravels and also firm clays, can only be drilled through and displaced if they occur as thin layers.

As this process is carried out in a single pass, the drilling depth is determined by the mast height and the operating weight of the drilling rig. Additional drilling depth is obtained by using a Kelly extension. The Kelly bar, which can be locked with the rotary drive, can extend the drilling depth by up to 12 m using both of its lock positions.

The displacement pile system offers significant advantages over conventional bored piles:

? Short construction period during pile installation.
? Low-noise, practically vibration-free and, therefore, environmentally friendly construction process.
? High load-bearing capacity per pile as a result of additional compaction of the surrounding soil and reliable penetration into load-bearing formation.

During construction of a displacement pile, hardly any spoil material is produced. The displaced volume of soil is pushed into the surrounding soils. As a result, there are no costs for off-site disposal of spoil. Due to the avoidance of spoil material, this technique is also extremely suitable for application in contaminated soil conditions.

Micro piling competence

Klemm Bohrtechnik, a daughter company of BAUER Maschinen, stands for high competence and constant innovation for the manufacture and development of drill rigs for special foundation and geothermal energy works. The product range covers hydraulic drill rigs for anchor, injectiongrouting, overburden, and double head drilling systems, as well as the corresponding hydraulic drifters, rotary heads and double head systems together with high performance drilling tools.

With over 2,500 already sold and with a two-digit number of rigs in India, Klemm drill rigs carry out all types of drilling jobs for anchoring, micro piling, injection grouting, ground investigation, well sinking as well as geothermal applications. The KR series product range offers various solutions. They are good ?value-for-money? drill rigs, particularly for micro piling projects.
The Klemm model types KR 708-2 and KR 709-2, respectively, are designed to meet the requirements of piling applications where restricted access and minimal headroom is encountered. With the capability to install deep 450 mm diameter and 600 mm diameter piles in spaces with headroom below 3.5 m, the KR 708-2 will primarily be deployed on network rail projects where there is a fall zone limit adjacent to the rails. It will also enable the customer to work within the limits of overhead electrification lines. A Klemm customer states that ?Restricted access always poses a challenge when it comes to piling, particularly when you need to achieve greater diameters. The available Klemm fleet of products had already proven their worth in terms of reliability and performance.?

The Klemm KR 708-2 and KR 709-2 are a sound investment to support the continued rail sector works and projects worldwide.

Where headroom is further restricted, the KR 708-2 offers even greater flexibility as the cathead can be removed to achieve a working height as low as 3.1 m. Conversely, where headroom is less restricted, an extension piece can easily be added to maximize production. The mast of the Klemm KR 709-2 can be extended up to a total length of 9.8 m.

From a logistic perspective, the Klemm KR 708-2 and the KR 709-2 offer proven time and cost savings. For example, as light and versatile rigs, they can either be tracked on a road/rail vehicle or transported on beavertail wagons or small trucks. This means a limitation of mobilization costs and allows easier access to job sites. While the KR 708-2 is short-masted, it does not compromise on performance, with the rig capable of drilling with rotary bored or sectional flight augers up to 660 mm in diameter as well as the Duplex, Odex and rotary percussive drilling methods.

The Klemm rig type KR 708-2 offers torque up to 27 kNm and retraction force up to 100 kN with a base weight of only 7 tonnes.

The KR 709-2 is the next larger machine which offers 43 kNm of torque and 130 kN of retraction force on a base machine of only 13 tonnes weight.

As all products of Klemm Bohrtechnik, these two rigs are available factory finished in customers color and corporate branding preferences for prompt and fully operational deployment. The KR 708-2 and KR 709-2 drill rigs are well adapted to the Indian market. Reliability, with high performance and ease of service round these machines off.

Fully hydraulic sheet pile drivers

RTG Rammtechnik is another daughter company of Bauer Maschinen GmbH. Their main field of activities is the development of versatile fully hydraulic sheet pile drivers in combination with powerful vibratory hammers. The RTG Universal Pile Driver series is available in two different machine types: the telescopic leader rigs and the fixed leader rigs. The advantages of the telescoping pile driving system lies specifically in its compact transport dimensions and in its very short set-up times. The machine is ready to operate in less than 60 minutes after arriving on site.

Fixed leader rigs have a solid one-piece mast. The construction allows the use of longer masts and higher torques.That is why the fixed mast machines are suitable not only for pile driving but also for various drilling operations.

The RTG rig series features important and essential advantages for the user:

High performance: Powerful vibratory hammers (centrifugal forces 105-145 t) with a strong active push and pull system leads to a high performance even in difficult conditions. Modern CAT C18 engines with an installed power of about 570 kW are providing sufficient power at any operation level.

Operational ease and safety: As the vibratory hammer with the pile in its clamp is running on a leader, it ensures a very safe and accurate working procedure. The dry sump lubrication of the vibratory hammers is integrated in the main hydraulic circuit of the machine with its extensive cooling system. This enables the vibratory hammers to run continuously even under hot climate conditions and prolong the service intervals.

The small foot print and the controlled pile handling make these machines ideal to work in densely built areas. The fine-tuned hydraulic system allows very sensitive working. The slew able mast (90? to both sides) provides the machine with a very high movability. Therefore the piles can be installed very accurately. Sharp corners and edges pose only little hassle; sheet pile walls can be installed even without using any guide frames.

The sophisticated BAUER B-Tronic computer system furnishes three functions: It is a real-time information system providing the machine operator via color touch screen with all important data during the driving process such as verticality of the mast, centrifugal force, activated unbalance, pile depth as well as lube oil temperature and pressure on the main hydraulic pumps etc.
Last but not least, the B-Tronic system is a failure detecting system which informs the operator on screen with a short message and a code about a possible failure which facilitates the troubleshooting very much.

Health and safety aspects: Operator comfort is increasing productivity and decreasing the danger of accidents. Therefore, the new BS65RS base carrier comes with a newly designed operator cabin featuring an ergonomical driver seat, a sliding door, tinted side windows, an integrated color touch screen, an air-condition and stereo system etc. Many more new details are contributing to raising the safety features even more.

Smaller, easier to handle counterweight pieces, a catwalk with guardrail to safely access the top of the base machine for maintenance and repair work, are typical examples for the stringent safety philosophy. An automatic recognition system of the front-end equipment prevents any misuse.

Environmental considerations: The rigs can be equipped with the latest powerful and fuel efficient Tier 4i engines which fulfill the most stringent international exhaust emission regulations.

For noise reduction purposes the designers came up with a new idea. The engine housing is completely closed, but on the side walls of the upper carriage they put automatic, performance-controlled flaps. The noise protection flaps open only in working mode and deflect the sound emissions upwards.

All RTG machine can basically run on biodegradable hydraulic oil. Fuel savings of up to 20 percent can be achieved with a newly developed economy mode and with an integrated fan control system.