VALVESYSTEM

ValveSystem is the innovative system for consolidating foundation soils by injecting special formulations, developed by DIFECH with the following two objectives in mind - Obtain a uniform and homogeneous distribution of the material in the volume of soil affected by the tensional bulb induced by the foundation; - Adopt the most suitable type of formulation in every geotechnical condition; The first objective was achieved through the use of PVC injection tubes equipped with special valves arranged at maximum spacing of 50 cm, while the second through the selection of different formulations specifically developed for geotechnical use.‎ The combined use of different formulations and the special valved liners allows VALVESYSTEM to effectively and homogeneously consolidate the entire tension-relieving zone of the foundation (tension bulb) in any type of soil, with the following results: - filling of sub-foundation cavities; - water removal; - improvement of geotechnical parameters with consequent increase in bearing capacity; - improvement of seismic behaviour.‎ ValveSystem was developed by DIFECH using the best technologies available on the market to guarantee the reliability and durability of the results obtained.‎ FIELDOF APPLICATION VALVESYSTEM's main application is in the consolidation of foundation soils, i.‎e.‎ the volumes of superficial soil on which direct foundations are set.‎ In fact, this technology is dedicated to the consolidation of the soil-foundation node with purposes such as increasing bearing capacity, filling cavities and seismic improvement.‎ It is important to emphasise how the possibility offered by ValveSystem to use different types of formulations makes this technology much more adaptable to different geotechnical contexts.‎ Although it enjoys the additional and undeniable advantage of minimal invasiveness, VALVESYSTEM, like any other foundation soil consolidation technology, cannot be applied indiscriminately to all cases of foundation failure or simple consolidation.‎ The proposal of any foundation soil consolidation technology requires a thorough knowledge of it, an equally thorough preliminary feasibility analysis, and the intellectual honesty of the person proposing it.‎ DIFECH's team of engineers and geologists boasts decades of experience in the field of foundation soil consolidation and is able to provide an unbiased and reliable opinion on the applicability and guaranteed results of VALVESYSTEM, proposing, as an alternative, Roto&Push piling technology.‎ ValveSystem can also be applied to industrial and non-industrial floors, both in the event of subsidence and in the event of consolidation.‎ VALVESYSTEM OPERATING METHODS The VALVESYSTEM intervention requires the preliminary drilling, in masonry and foundation, of 25 mm diameter sub-vertical through holes made with manual drills at variable centre distances between 1 and 1.‎5 m depending on the type of foundation and soil.‎ The next stage involves the insertion in each drilled hole of special injection barrels valved up to the bottom of the hole and the external sealing of the hole itself at the level of the walking surface to prevent undesired material reflows during the injection phase.‎ Injection into each barrel is carried out by continuously monitoring flows and pressures in the injection circuit on a terminal, as well as lifting the structure along the entire face with the aid of laser levels and multiple readers attached to the structure.‎ Injection continues until the millimetric lifting of the structure is reached, indicating the reactivation of the foundation as a result of the filling of all underlying cavities and in any case the compaction of the soil until the development of strengths greater than the stresses transmitted by the foundation.‎ The final test of the VALVESYSTEM intervention is carried out by means of penetrometric tests and comparing the results with those of similar tests carried out prior to the intervention to calibrate the injection parameters (drill hole spacing, length of pipes and type of formulation).‎ For extensive quality verifications, pre- and post-intervention geophysical tests (seismic and electrical tomography, etc.‎) can be added to the penetrometry tests.‎ MATERIALS The materials used in ValveSystem, depending on application conditions, can be divided into: - two-component synthetic resins; - cement-based mixtures; - chemical mixtures.‎ The materials used are supplied by leading national manufacturers, subjected by them to the stringent controls/verifications foreseen and in compliance with the national and EU regulations of framework and reference for each of them.‎ The materials used are environmentally friendly, non-biodegradable and reaction-caused, stable and inert in compliance with current environmental regulations (Legislative Decree 152/2006).‎ ADVANTAGES Compared with other foundation soil consolidation technologies, ValveSystem- greatly limits invasiveness, impact and site duration; - offers the possibility of choosing between different formulations depending on geotechnical conditions; - ensures uniform and homogeneous distribution of the injected formulation, and therefore consolidation, in the volume of soil affected by the stress bulb;- allows lifting for partial/total recovery of subsidence, (compatible with structural response); - does not produce waste material, avoiding transport and disposal at authorised dumps; - does not produce harmful vibrations.‎