CONDI|II GEOTEHNICE

Studiu geotehnic SC AZOMURE SA Pag. 4

STUDIU GEOTEHNIC

"INSTALAREA STATIEI DE POMPARE IN CAMERA DE DISTRIRUIE A BAZINELOR DE OMOGENIZARE EXISTENTE AZOMURE I MONTAREA CONDUCTEI DE TRANSPORT APE UZATE LA NOUA STATIE DE EPURARE CRISTETI"TRGU MURE, JUD. MURE

BENEFICIAR: SC AZOMOURE SAPROIECTANT GENERAL: SC ALUDESIGN CONSTRUCTION CIVILE SRL

EF STUDIU

ING. SZKELY ISTVN

-MAI 2015

Cap. 3 CONDIIILE GEOTEHNICE ALE AMPLASAMENTULUIChap. 3 GEOTECHNICAL CONDITION OF EMPLACEMENT3.1. Stratele superioare formate din umpluturile neomogene i depozite aluvionare slab consolidate, coezive moi sau necoezive afnate, (eventual materii organice), nu sunt omogene i au capacitate portant variabil i sczut n consecin nu se recomand ca teren de fundare.Nu se poate releva o startificaie legat pn la complexul marnos.

3.1. The top layers made of heterogeneous fillings and weak alluvial deposits, soft cohesive or loose non-cohesive soils, that are not homogeneous and have variable low load capacity and therefore not recommended as foundation soil.Unable to link the stratifications until the marl complex.

3. 2. Complexul bazal marnos a fost interceptat la 5,60 m (F1)-6,50 m (F2) conform forajelor executate n zon format din marne argiloase sau nisipoase cenuii (plastic vrtoase la contactul cu depozitele aluvionare), cu intervale de nisip marnos sau marne grezoase, compacte semistncoase, prezint urmtoarele caracteristici geomecanice medii de calcul, care se pot lua n considerare la proiectare- v = 20-20,50 KN/cm3 greutate volumetric n stare natural;- = 20-22 unghiul de frecare intern;- c = 50-70 kPa coeziunea;- Ic = 0,95 indice de consisten; - Ip = 40-45 indice de plasticitate; - M2-3 = 15000-20000 kPa modul edometric; - Pconv-calc = 300-400 kPa presiunea convenional de calcul;- = 0,30 coeficient frecare dintre fundaie teren;- = 0,35 coef. lui Poisson (coef. de deformare lateral);- K= 10-5-10-8 cm/s valoarile coeficientului de permeabilitate; - ks = 63-100 MN/m3 coeficient de pat (conform normativ NP112-04, pentru placa ptrat cu latura de 30 cm);

3.2 Marly bedrock complex, (consolidated), composed grey marly layer made from clayly sandy marl with sandy marl levels, has the following geomechanical calculation characteristics, which may be taken into account in the design:- v = 20-20,50 KN/cm3 natural volumetric weight;- = 20-22 angle of internal friction;- c = 50-70 kPa - cohesion;- Ip = 40-45 plasticity index; - Ic = 0,95 consistency index; - M2-3 = 15000-20000 kPa oedometric modulus;- Pconv-calc = 300-400 kPa basic conventional pressure;- = 0,30 friction coefficient between foundation & land;- = 0,35 Poissons ratio(coefficient of lateral deformation);- K= 10-5-10-8 cm/s permeability coefficient values; - ks = 63-100 MN/m3 coefficient of bed (elasticity) ( by normative NP112-04 for square form 30x30 cm plaque).Cap 4. CONDIII DE FUNDAREChap. 4 FOUNDATION CONDITIONS4.1. Avnd n vedere: stratificaia i nivelul hidrostatic ascensional al apei de pe amplasament, agresivitatea excesiv a apelor mai ales cea amoniacal tipul de structur principal specificat n tema de proiectare ca fiind o platform de 9x13 m pe care se va monta o pomp uscat de capacitate mare caracteristicile fizico-mecanice ale terenului de fundare n zona de influen a fundaiilor existena unui strat gros de umplutur neomogen neconsolidat sub solul vegetal de pe amplasamentul studiat neomogenitatea att din punct de vedere granulometric ct i a gradului de compactare a statului aluvionar necoeziv afnat i coeziv moale, n proporii foarte variabile categoria geotehnic 2-3 a lucrrii, cu risc geotehnic moderat sau major, la proiectare i executie se vor lua n considerare recomandrile de mai jos.

4.1.Given the: specific stratification of the raising water in the nearby basins . chemical aggressivity of the water more specifically ammonia. structures being a slab of 9x13m that will have mounted on it a dry pump. physical and mechanical characteristics of the foundation soil in the area of influence of foundations . the existence of a thick layer of unconsolidated inhomogeneous filling in topsoil from the site studied. inhomogeneity both in terms of grain size and the degree of compaction of the loose and soft cohesive alluvial layer, in highly variable proportions. 2-nd geotechnical category of work, with moderate geotechnical risk, design and execution will consider the recommendations below.

4.2. Proiectantul de rezisten va alege soluia optim de fundare (fundaii indirecte prin piloi, fundaii directe i continue, fundaii izolate, blocuri de fundare etc.) n funcie de natura constructiv a obiectivelor proiectate, pe baza caracterisiticilor geomecanice ale terenurilor, furnizate de prezentul studiu.

4.2. The designer will choose the best solutions for the foundation (direct and continuous foundations, insulated foundations, foundation blocks, indirectly foundation by piles etc.) depending on the constructive nature of project objectives, based on geomechanical features of land provided by this study.

4.2.1. Fundaii tip radier pe piloti Avnd n vedere stratificaia din amplasament si proprietaile terenului de fundare, o construcie ce va fi supus la sarcini dianamice nu poate fi fundata dect indirect, pe piloti forati (puttori de vrf) de diametru mare ( min 40 cm).Acetia pot fi calculai ca piloi portani pe vrf, cu o fie activ de minimum 10 m, care vor fi ncastrai n stratul de marn cenusie-compact tare, de minim 2-3 diametre.Cel puin un pilot din lucrare va fi ncercat la compresiune, respectiv smulgere.Capetele piloilor vor fi incastrate ntr-un radier pe care se vor fixa bazele structurii metalice de susinere.Sustinerea pamantului de sub platforma din lateral se poate realiza prin metoda piloior tangeni,Calculul i dimensionarea piloilor se va efectua conform Normativ privind proiectarea geotehnic a fundaiilor de piloi , Indicativ NP 123 : 2010.Alegerea tipului de beton pentru piloi va ine cont de agresivitatea excesiv a apelor subterane din zon.

4.2.2. Slab foundations on drilled pilesGiven the location and stratification of foundation soil properties, a construction that will have dynamic loads can be founded only indirectly on large diameter drilled piles.They can be calculated as the peak load-bearing piles with active cards at least 10 m, which will be embedded in gray marl layer-compact hard, at least 2-3 diameters.At least one pilot work will be tested for compression respectively for tearing.Heads of piles will be embedded in a radier that will supporting bases of towers.For the ground bracing of the soil under the existing platform on the side we can make a contiguous piles system.Calculation and dimensioning pilots should follow Standard on geotechnical design of foundations for pilots, indicative NP 123: 2010.

In the choice of the concrete of the piles it must be considered the excessive aggressiveness of groundwater in the area

4.2.3. O varinat alternativ ar fi fundarea pe radier general dispus peste o pern de balast compactat controlat n trepte cu strat de blocaj n baz.n acest caz n funcie de adncimea bazei pernei de balast se va avea n vedere evacuarea apelor freatice n timpul lucrrilor de execuie a pernei sau dispunerea pernei deasupra nivelului de stabilizare hidrostatic a apelor subterane. Se recomand excavarea umpluturilor eterogene i a depozitelor aluvionare eterogene cu capacitate portant redus din spturi i nlocuirea spturilor suplimentare cu material autohton tip balast sau material din gropi de mprumut. Avnd n vedere variaiile mari att a granulozitii ct i a gradului de compactare a stratelor aluvionare necoezive sau coezive se recomand omogenizarea terenului prin aternere succesiv n trepte de sorturi adecvate de balast sau piatr spart andezitic rezistent la apele agresive (recomandat start de blocaj n baz din blocuri coluroas gabaritice din andezit), mpnat cu nisip care se va compacta cu mijloace mecanizate grele pn la obinerea capacitilor portante impuse de ncrcrile aduse de construcii. Pentru lucrrile de omogenizare se recomand executarea de msurtori tip Proctor normal respectiv dup terminarea omogenizrii se vor executa msurtori cu placa static tip Lukas n 4-5 puncte. Toate aceste lucrri sunt necesare pentru reducerea la minim a tasrilor maxime probabile n timp ct i evitarea tasrilor difereniate care ar fi extrem de periculos privind funcionarea n condiii optime a pompei de mare capacitate de tip uscat.

4.2.3. An alternative would be the concrete slab be placed over a cushion of compacted ballast.In this case depending the depth of the cushion the water that it incounters must be evacuated or the cushion must be place on stabilizing above the hydrostatic groundwater.Its recommended that the fillings should be excavated and replaced with native material or ballast type material of borrow pits. Given the wide variations both grain size and the degree of compaction of non-cohesive alluvial strata recommended by littering the field homogenization with successive steps of varieties suitable ballast stuffed with sand or crushed stone to be compact with heavy mechanized means to achieve capacity bearing loads imposed to the construction. For homogenization work is recommended that Proctor normal type measurement. After homogenization that will run static plate type measurements Lukas 4-5 points especially in cylindrical type tanks where have a wide excavations area.All these works are necessary to minimize the probable maximum subsidence in time and avoid differential settlements that would be extremely dangerous on the optimal functioning of a technological flow.SC ALUDESIGN CONSTRUCTION CIVILE SRL