High-Capacity Micropiles

Our Micropiles are capable of carrying 175+ Tons, they underpin foundations, enhance structure stability, transfer heavy loads and avoid underground utilities.

Micropile Overview

Micropiles, also known as minipiles, pin piles, and needle piles, are 3-10″ diameter friction or end bearing piles capable of carrying loads of 175 tons or more, however, 40-50 tons are most common.

Micropile Installation Process

Typically, the micropile casing is advanced to the design-tip depth using specialized rotary drilling equipment and techniques. Once the tip depth has been achieved the casing is thoroughly flushed clean and a fully threaded, high strength, and centralized bar is inserted into the casing to full depth and the casing is fully grouted. After grouting, the casing can either be partially extracted, leaving the upper section cased and the bottom section bonded or the casing can be completely removed resulting in a fully-bonded or uncased micropile.

Types Of Micropiles

Uncased Micropiles

In tension/uplift applications the uncased pile, or fully bonded pile, is typically the micropile of choice. After grouting, the casing is completely removed leaving the high-strength cement grout and centralized threaded bar in place to interface directly with the soil or rock.


Cased Micropiles

In compression and tension applications, the drilling procedure is the same as uncased piles, however, after the initial grouting, the casing is partially extracted exposing the bond length/ zone. The upper section of the pile remains cased, providing buckling resistance and lateral stability by virtue of the heavy wall casing.


Hollow Bar Micropiles

A hollow-bar micropile is comparable to an uncased micropile and can be used for both compression and tension loads. Uncased, these piles perform better in tension applications, however, a casing can be added to increase compression capacity. These piles do not require pre-drilling as the hollow-bar micropile is injected with neat cement grout and drilled simultaneously until the pile reaches design depth. Different sacrificial bits are used to accommodate any rock or soil type including hard rock, soft rock, and clay soils.


Helical Micropiles

Helical micropiles carry tension and compression capacities ranging from 5-50 tons. These micropiles are installed in sections using a high torque hydraulic motor. Sections may be steel square solid bar shafts or steel round hollow tube shafts or a combination and are typically galvanized. They derive their load capacity from helically shaped plates which are welded to the steel shaft. The capacity is empirically related to the torque required to install them. Thus, the installation depth is determined by the required capacity and the torque required to achieve the design capacity.


Typical Micropile Applications


Typical Structures:

Service Area

At Dosdourian Enterprises Inc. we specialize in chemical grouting, helical piles, Waterstop and Foundation Repair in South Florida.