Services

Landslide Remediation/Hillside Stabilization

Whether they were created by acts of nature or caused by people, PLI Systems has many tools and equipment to repair landslides. We incorporate tie-back anchors, drill piles shotcrete, soil nails and many other techniques to solve the problem.

Light-Weight Fills: Foam and Cellular Concrete

Foam and Cellular concrete: Light weight fills perfect for reducing the lateral pressure demand on walls and also great for back-filling difficult access locations. Light weight cellular concrete fills can be pumpable and be as light as 20 pounds per cubic foot and also come in pervious cellular concretes. Geofoam blocks are also available from 1 pcf to 2.5 pcf to be used in roads, buildings, or even backyards.

Drilled and Grouted Tie-Back Anchors

These can be from 1 inch diameter up to 12 inches diameter and typically range from 10 feet deep to 100 feet deep. Tension and compression capacities of a thousand pounds to 1 million pounds.

Helical Anchors and Piles

In the right soil conditions these are quick and efficient at developing tension or compression loads from a thousand pounds to 500 thousand pounds. Depths typically range from 10 feet to about 100 feet deep and can be installed vertically or horizontally. Square shaft helices come in 1.25”, 1.5”, 1.75”, and 2.25” material. Pipe Helices are made in many sizes such as 2-7/8”, 3-1/2”, 4”, 5”, 6”, 7”, 8”, 9’”, 10”, 12”, 14”, 24” diameters.

Drilled Shafts (Caissons)

Drilled shafts are great for compression load capacities ranging from 20 thousand pounds to well over a million pounds. They can also handle up lift and torsion forces. Typical diameters are from 12”, 14”, 16”, 18”, 20”, 24”, 30”, 36”, 48”, 60”, and 72”. These can be installed with wet , partially cased, or open hole methods in gravels, sands, silty  and even socketed in solid rock. Typical depths vary from 10 feet to 70 feet.

Elevator Jack Shafts

Fairly simple elements drilled as 18”, 24”, or 30” diameter and range in depth from 15 feet to approximately 50 feet deep steel casing is installed in the shaft vertically to allow for the installation of the elevator cylinder. The drilling may occur for existing elevators or new installations

Displacement Piles

Can be created of diameters from 6” up to 24” in depths from 10 feet to 60 feet deep. Displacement piles are especially useful in soft soils where the soil is compressible and in contaminated soils to avoid creating spoils needing removal. Capacities range from 10,000 pounds to around 100,000 pounds.

Wall Construction

Walls maybe built with driven pipe piles, driven wide flange piles drilled piles tie-back anchors, concrete or shotcrete, soil nails and shotcrete, gabion baskets, small concrete blocks or large concrete blocks such as ultra-block, or other geo-grid.

Injection Boring

Is used for micropiles, tie-back anchors or soil nails where soil will not stay open in a drilled hole. Typically range from 2” to 10” diameters and capacities of 1,000 pounds up to 500,000 pounds. Installed depths vary from 10 feet to 150 feet and can be installed horizontally as well as vertically.

Underpinning

Underpinning is the process of strengthening the foundation of an existing building or other structure. Underpinning may be necessary for a variety of reasons:

• The original foundation is simply not strong or stable enough.
• The usage of the structure has changed.
• The properties of the soil supporting the foundation may have changed (possibly through subsidence) or were mischaracterized during design.
• The construction of nearby structures necessitates the excavation of soil supporting existing foundations.
• The structure has settled and the stabilization requires leveling.
• To increase the depth or load capacity of existing foundations to support the addition of another story to the building (above or below grade).
• It is more economical, due to land price or otherwise, to work on the present structure’s foundation than to build a new one.
• Earthquake, flood, drought or other natural causes have caused the structure to move, thereby requiring stabilization of foundation soils and/or footings.

Rock Anchors

Rock anchors are used commonly as part of retaining walls, and as part of a system to resist movement of a foundation, or slope. Most rock anchors consist of a pre-drilled hole that is filled with grout. A threaded steel anchor bar that is sheathed is inserted into the hole and grouted. The bar is tensioned and locked off to the appropriate specifications of the particular job. There are many sizes and weight capacities of rock anchors depending on whether they are for small house foundation type jobs or for retaining large structures such as bridges or rock cliff faces.

Rock Coring

In various projects it is imperative to analyze quality and quantity of consolidated geologic formations. We accomplish this objective by rock core sampling. We utilize wireline core drilling and other methods. In geotechnical coring, depths may be from 5 feet to 150 feet. We bring the rock samples to the surface for analysis by the engineer.

Dewatering

Is necessary where excavations encounter water. Dewatering wells are designed to lower the local water table. Diameters for the wells are drilled anywhere from 6” to 30” and typically extend up to 60 feet deep.

Micropiles

Micropiles, also called mini piles, are often used for underpinning or seismic upgrades. They are also used to create foundations for a variety of project types, including highway, bridge and transmission tower projects. They are especially useful at sites with difficult or restricted access, or with environmental sensitivity. Micropiles are made of steel with diameters of 60 to 200 mm. Installation of micropiles can be achieved using Air Rotary or Mud Rotary drilling, impact driving, jacking, vibrating or screwing machinery.

Soil Nails

Soil nailing is a construction technique that can be used as a remedial measure to treat unstable natural soil slopes or as a construction technique that allows the safe over-steepening of new or existing soil slopes. The technique involves the insertion of relatively slender reinforcing elements into the slope – often general-purpose reinforcing bars (rebar) although proprietary solid or hollow-system bars are also available. Solid bars are usually installed into pre-drilled holes and then grouted into place using a separate grout line, whereas hollow bars may be drilled and grouted simultaneously by the use of a sacrificial drill bit and by pumping grout down the hollow bar as drilling progresses.

Spiral Nails are a non-grouted lower cost alternative to drilled and grouted soil nails.

Grouting

Grouting is used for various applications. There are hundreds of mix designs which are tailored to the grouting application. Typical products in the mix are cement, water, sand, fly ash, bentonites, and admixtures. Characteristics such as set time, density, and compressive strength are all adjustable.