A slurry separation plant sets the maximum sustainable advance rate of a microtunneling drive: the machine can only advance as fast as the plant removes solids. It removes excavated solids in stages defined by particle size, conditions the slurry back to its working density and viscosity, and returns it to
Curved microtunneling – steering a remotely controlled, non man-entry jacked pipeline along a horizontal or vertical curve between shafts so the line can follow a road, a river, a rail corridor or an existing utility instead of running straight between two fixed points – has a minimum radius (the tightest
Microtunneling tolerances – the permitted departure of a remotely controlled, non man-entry jacked pipe from its design alignment – define how far the installed pipe may sit from its design line (horizontal position in plan) and its design grade (the designed fall, expressed as a percentage or an elevation), and
A microtunneling geotechnical investigation is the desk study and ground investigation package that decides whether a drive is feasible and what machine, face support and jacking force it needs. Its three outputs are a borehole layout, a parameter list and a baseline deliverable set, and its placement rule is fixed:
Microtunneling grade control is the closed loop of measurement, reporting and steering that keeps the machine on its design line (horizontal position in plan) and its design grade (the designed fall, expressed as a percentage or an elevation) as it advances. Accuracy as good as ±10 mm has been reported
Microtunneling groundwater control is the package of measures that keeps water out of launch and receiving shafts and holds the face and annulus stable while a remotely controlled machine advances below the water table. It combines shaft dewatering or cut-off, entry and exit seals, a balanced support medium at the
Microtunneling jacking force is the total thrust the jacking frame must deliver to advance the machine and push the pipe string from the launch shaft, and it is the sum of face resistance at the machine, friction along the pipe string, and any force added by curvature. Published friction values
Overcut in microtunneling is the annular clearance the machine cuts beyond the outside diameter of the pipe, and it is the single dimension that ties steering, lubrication and settlement together. Its normal size is about 12 to 19 mm on the radius in soil and more than 25 mm in
Microtunneling pipe materials are selected on one governing criterion: whether the pipe and its joint can carry the jacking load at the governing point of the drive while staying watertight and on line. Direct jacking is dominated by reinforced concrete pipe (RCP), vitrified clay pipe (VCP), polymer concrete and glass-reinforced
Microtunneling settlement is ground movement caused by the drive, and it is controlled by limiting volume loss: face loss and over-excavation, the overcut annulus, slurry or lubricant loss into the ground, joint drag, shaft-related loss, and groundwater drawdown with consolidation all contribute, and they are managed with face pressure control,
1. What Are the Most Common CIPP Liner Failure Modes? The most common CIPP liner failure modes include: These failures are mainly caused by poor design, inadequate surface preparation, improper curing, installation errors, and unsuitable material selection. These CIPP defects and trenchless rehabilitation failures generally fall into five main categories: structural
Soil stability before a trenchless project is measured through five main steps: These tests determine soil strength, density, groundwater conditions, and the risk of collapse or hydraulic fracture (frac-out) before drilling begins. Soil Stability Testing Process at a Glance Investigation Stage Primary Test / Method Core Purpose Site Review Geological
The maximum distance a pipe can be pulled using trenchless methods ranges from approximately 50 meters to more than 3,000 meters, depending on the installation technology, pipe characteristics, ground conditions, and equipment limitations. For new pipeline construction, Horizontal Directional Drilling (HDD) typically achieves 200–800 meters per pull. For pipeline rehabilitation, specialized
Best Materials for Trenchless Pipe Rehabilitation The most widely used and effective materials for trenchless pipe rehabilitation are thermosetting resin systems—specifically epoxy, polyester, and vinyl ester—combined with reinforcement fabrics such as fiberglass or polyester felt. For most municipal sewer rehabilitation projects, polyester CIPP offers the best cost-to-performance balance, while epoxy CIPP is preferred for pipes
There is no universal pressure limit for inflatable pipe plugs. The maximum back pressure depends on the plug design, size, pipe diameter, pipe material, and installation conditions. Most inflatable pipe plugs are rated from 1 bar (14.5 psi) to more than 13 bar (188 psi). Always follow the manufacturer’s specific
English English 
Arabic
Russian
Spanish
French
Vietnamese
Polish
Thai
Indonesian
Turkish
Portuguese
