MICROPILES, TIE RODS AND WELLS
Micropiles, active (strands) and passive (dywidag bars) tie rods with relative stringing and testing by Oleodynamic unic. Furthermore, will realize domestic wells.
ESECUTION METHOD
- Down the hole (DTH) Pneumatic Hammer Drilling
- Propeller Drilling
- Micropiles Drilling with fluid injection tip
In case of hole stability problems the perforations can be performed with provisional coatings
MICROPILES AND TIE RODS
In addition to geological, geophysical and laboratory surveys, the company, through specialized staff, performs special drilling works during construction works.
In particular it performs the works of drilling, micropiles and tie rods, for the construction of foundation, buildings consolidation and civil works as well for the slope stability
The micropile is a foundation pile having a diameter size between 90 and 250 mm and a length generally up to 12 – 15 meters.
Although the single micropile has a bearing strength less than a medium diameter pile (250 to 800 mm) or larger diameter pile (over 800 mm), using different micropiles it is possible to obtain a stable and not much yieldable sub-foundation support on which can be placed a plate foundation.
Realization of piles requires wide work space and a fairly considerable deposit space, in urban areas these conditions are not always respected, especially in proximity of existing buildings or protrusions such as balconies, eaves, etc; in this case, although with a slight increase of costs, micropiles become the best technologic solution for soil remediation.
A wide use of micropiles, due to the modest size of the necessary equipment for their realization, is for the bulkhead and/or diaphragms like soldier pile walls.
These bulkheads are constituted by a series of micropiles of right length arranged along a straight line (or offset mash called “quincunx”), realized in variable spacing (between 30 and 70 cm) as a function of the soil characteristics and the excavation heights. They also enable the support of the excavation face allowing to safely operate and safeguarding the someone else’s property and are particularly suited for the stabilization and for the safety measures of hydrogeological slopes.
EXECUTIVE STEPS
The construction phases of micropiles can be summarized as follows:
- placement of the equipment on the point of drilling and verification of required design parameters (position, verticality,…);
- drilling execution (with tools such bottom-hole hammers, propellers, tricone, triblade, mold tube, having different diameters and drilling technologies depending on the specific soil characteristic) with simultaneous implementation, if necessary, of coating shirt to prevent the clogging due to the soil falling off from the walls of the creating well;
- installation of tubular metal armor (metal pipe)
- injection of cement mixture under pressure (high cement content concrete, water/cement and/or bentonite mixtures) from the bottom to the top by a tube placed inside the tubular armature with simultaneous coating recovery
TIE RODS AND DYWIDAG BARS
To limit excessive deformation of the structure and to ensure a better ability of the retaining work, the soldier pile walls are implemented with both active (strands) and passive (dywidag bars) tie rods.
TESTING OPERATIONS AND STRINGING
The company, in addition to the construction works, is also involved in the subsequent phases of micropiles testing for the definition of the load-bearing capacity, the stringing of the tie rods by the oleodynamic unit and the tightness testing.
BIERREGI SRL WORKS WITH PROBES
- Beretta T45 (for limited spaces)
- CMV MK 600
- Comacchio MC 600
- Electric Core Drill CORDIAM