Horizon Dig Technology Sdn. Bhd.

is present, at least partially, in many forms of trenchless teachnology that we see today. If we think of the board definition, then there is some jacking of pipe that is involved in Slurry Pressurized Microtunneling, Manshield Pipe Jacking and Auger Boring.

1) Slurry Pressurized Micro-tunnelling
Slurry pressurized microtunnelling is one of the modern technique used in the project for the pipe jacking industrial. Micro tunnelling are the technologies that have the potential for significantly improved environmental performance relative to other technologies. Micro tunnelling protects the environment, less pollution, recycle more to their wastes and handle the waste in a more environmentally acceptable way. Technique:
Microtunneling technique is using the hi-technologies equipment to jack the jacking pipe size from 30mm to 2100mm diameter through a wide range of geological conditions. Especially for layer or soft silt day layer. Microtunnelling is using CCTV to monitor the level and alignment. This monitoring guidance system will provide all efficient and accurate monitoring of the system. The system provides the graphical display of the cutter head position and the technical data that can be print out for as-built records. In the microtunnelling techniques, the soil in front of the cutter head will be cutted and mixed with the water which is pumped in to the cutter head. The mixture becomes slurry and the removal of slurry by using the slurry pressurized pump.

2) Manshield Pipe Jacking
The manshield pipe jacking is a technique where the shield is designed to maintain and support of the tunnel face at the pressure required to prevent subsidence. The front shield chamber which will always be plugged with the excavate materials by means to support the face and possibility of water ingress or soil collapsed. The manshield method can be applied in various type of pipe installation the size from 750mm diameter and above. There is no restriction and limitation method but care on the face stability should be always taken in concern. This technique is more suitable for good soils, obstruction of old piles and other obstruction conditions. The manshield pipe jacking needs a strong thrust wall which provides reaction against the jack. The high pressure hydraulic jack provides the driving force necessary for thrusting the pipes directly into the ground. Excavation and removal of soil can be by manual or mechanical means, depending on the type of soil.

3) Pilot Auger Boring / Thrust Boring
The pilot auger boring is a technique to install a small range of diameter from 150mm to 600mm. The auger tunnelling system had become a competitive to open pit construction. The modular concept of the system enables to adapt it to suit different pipe dimensions and different types of soil, whether in dry earth or ground water. Pilot auger boring technique is to drill the pilot tube between the pre-excavated launch and reception pits. The drill path must be straight and the direction of the drilling head can be adjusted of any stage during the bore to steer if any deviation along designed pipeline. A pilot tube is first drilled along the require path and the second stage operation bore is followed by an auger head to excavate the soil and followed by the product pipe. When the cutter excavate the soils, the pipes to be embedded are inserted. Almost all the thrusting load is carried by the cutter and screw-conveyors. The soil in the pipes will be transported out by the screw-conveyors. When the pipe reach the reception pit, the screw-conveyors to be removed.