Hydraulic Pushing Technology - Lankelma Site Investigation

Hydraulic Pushing Technology

Advantages

Hydraulic pushing technology saves time and money - it is rapid (up to 10 times faster than traditional testing methods)  and produces instantaneous data, no waiting for laboratory results.

Pushing a cone into the ground avoids most soil disturbance, giving high quality test results and leaving  little or no trace, as you can see from the images above of the installation of an inclinometer.


Hydraulic rams

Hydraulically powered pistons or �rams� are used. These may be single or double rams of variable capacity. Generally for site investigation operations 5 tonne, 10 tonne and 20 tonne capacity rams are utilised. However, 30 and 40 tonne capacity rams could be operated. The rams are mounted on to a test vehicle, frame or bed (see rigs).


Reaction force

Generally the rigs provide the reaction force required to oppose the push force of the hydraulic rams.  CPT vehicles include wheeled trucks, caterpillar tracked vehicles, reaction frames, cantilever platforms and specialised combi-vehicles (rail truck and track-truck).

Weights of such vehicles vary from 2.5 to 40 tonnes. Light weight rigs can be screwed into the ground or have extra weights added to them to gain extra reaction force.


True in-situ soil conditions

Hydraulically pushed  cones and instrumentation cause minimum remoulding of the soil as they are pushed into the ground. The recorded data can therefore reflect the true in-situ soil conditions.


Speed

Hydraulic methods are rapid. For example, in a single 8 hour day the following can be achieved:

Cone penetration testing  - 130 to 200m per day

Instrumentation - 200m per day

Continuous sampling - 12-15m per day

Ground source heat exchangers - up to 250-300m per day

Environmental

Hydraulic pushing equipment is quiet and does not produce vibration. Therefore it can be used virtually anywhere without causing disturbance (e.g. offices or residential areas). Similarly the systems are compact and robust and so can be used in open space, restricted access or headroom sites.