qertox.blogg.se - Trenchless directional drilling

#Trenchless directional drilling install

Preliminary design evaluated various trenchless methods to install the various utilities, including microtunneling and horizontal direction drilling. Ground conditions included 40 to 50 feet of very soft Young Bay Mud underlain by denser Old Bay Mud and claystone bedrock. The utilities to be installed were a 22-inch sewer force main, a 12-inch reclaimed water main, two 18-inch water mains, and four 4-inch conduits for fiber optic cables. The City of Vallejo and the Vallejo Flood and Wastewater District collaborated on a project to install various utilities to from Vallejo to Mare Island under the Mare Island Strait.

Hydrofracture risk in soft surficial soils.

12″ rec’d water, 22″ sewer, two 4″ conduits.

Twin 2,600′ bundles under Mare Island Strait.

Which Method to Use When Estimating Maxi-HDD Installation Loads- ASTM F1962 or the PRCI Method.

Slavin, Larry and Scholl, Jeff (2014).

Discussion of ASTM F1962 or “How are the Pulling Load Formulas Derived and How They Are Used?”.

Slavin, Larry and Petroff, Larry (2010).

MAB-07 (2020) - MAB Guidelines for Use of Mini-Horizontal Directional Drilling for Placement of HDPE (PE4710) Pipe in Municipal Applications.

CAPP Planning Horizontal Directional Drilling for Pipeline Construction.

ASCE Pipeline Design for Installation by Horizontal Directional Drilling.

The pulling load on the polyethylene pipe must not exceed the allowable tensile load, or safe pull strength of the pipe.Īlong with the recent developments in drilling equipment and operator expertise, there has been, and will continue to be, a dramatic increase in the installation of water and sewer systems using directional drilling. As with any pipe pulling technique, the movement of the drill string and the pipe string should be monitored. As the drill string is withdrawn to the drilling rig, the back-reamer enlarges the borehole and the pipe string is pulled into the hole. The pipe string is attached to the back-reamer through a swivel device.

The cutting head is then removed and a back-reamer attached. Drilling mud is used to cool the cutter and transmitter electronics, to flush excavated soil from the borehole and to lubricate the borehole. Using directional drilling techniques to guide a drill string along a bore path under obstacles such as rivers, lakes, railway crossings or highways, enables replacement of existing water lines, or installation of new ones, at a relatively rapid rate.Īs the hole is bored, a steel drill string is extended behind a cutting head. Horizontal directional drilling is often used where open cut installations are not feasible, such as road and river crossings.

It's flexibility, strength and fused joints as strong as the original pipe itself, make it ideal for HDD applications. Polyethylene pipe is the pipe of choice for trenchless installations using directional drilling.

Trenchless technologies, such as horizontal directional drilling, pipe bursting and slip lining allow the entire water supply and drainage system of a city to be replaced without causing a major traffic jam and incurring the enormous cost of restoring streets and roads. Horizontal Directional Drilling Horizontal directional drilling (HDD) is a trenchless construction method used to install pipelines of various sizes and materials below the ground surface.