ADVANTAGES OF MICROPILES:

• Capacity 1000kN-3000kN SLS Load.
• Ability to install in tight access installations (5ft wide) and low headroom (8ft high)
• Limited or no spoils/vibrations.
• No dewatering required – can be installed in a high water table application.
• Obstructions in soil (boulders, rubble, etc.)

Micropiles are high-performance, high-capacity drilled deep foundation elements typically between 5–12 inches in diameter that can extend to depths of 200 feet and achieve working loads of over 200 tons. Micropiles are comprised of high-strength steel casing, rebar and grout.

Micropiles have been used mainly as elements for foundation support to resist static and seismic loading conditions, and as in-situ reinforcements for slope and excavation stability. Many of these applications are for transportation structures.

Micro Piles cost about $120 per linear foot, which is more expensive than the original H-piles. Changing the foundation system to Micro Piles will cost an additional $120,435.

Micropiles are small diameter drilled and grouted friction piles. Each pile includes steel elements that are bonded into the bearing soil or rock – usually with cement grout. The bearing stratum is logged during installation drilling to assure that bearing capacity is adequate.

Micropiles are defined as bored piles with diameters not exceeding 250mm. Micropiles were first constructed in Italy in 1950s and were given the name “root piles”. Whenever bored piles (larger diameter) and driven piles are considered feasible, they should be more economic than micropiles.

Hollow Bar Micropiles are drilled into the ground using a sacrificial drill/grout tip while pressurized grout is pumped down the hollow bar while drilling. Micropiles can be used for practically any soil condition, and load is gained through bond stress between the grout and the surrounding soils.

Piles were typically concrete, installed to a depth of 300 mm or more. Houses could be supported fully on piles, or have internal bearer support only provided by piles.

When getting pricing from us you will notice that Helicals can cost around $30 dollars per foot. Meaning a Helical around 20-ft can be estimated around $600 dollars.

How are micropiles installed?

1. The casings of the minipiles are advanced as piles are drilled into bedrock.
2. Drill rod is removed.
3. A reinforcement load bar is lowered into the casing, for added capacity.
4. Cementitious grout is pressure fed into the minipile casing and rock socket to ensure bonding.

Brass functions well in American chambered guns. Brass is more malleable in that when the primer ignites the powder, the brass case expands in the chamber pressing against the chamber walls. Its pressure is held by the steel chamber, allowing the bullet to exit the case to move down the bore’s rifling to the muzzle.

Part of the answer to this question is the nature of the case material itself. When heated, steel does not expand and contract the same way that brass does – in fact, brass expands 1.5 times as much as steel.

Additionally, brass ammunition can be reloaded if you have the necessary equipment while steel cases are generally not reloaded. We at Bear Creek Arsenal do not recommend using steel ammunition in your complete firearm or upper assembly, but understand if the availability and cheaper price do cause you to try it out.

The chamber tolerances of an AK rifle are much looser than those of an AR-15. Steel cases function in those guns, because the chamber is simply not as tight. For same reason, American chambers have closer tolerances making steel ammo reliability iffy.