natgillin/translations-raw huggingface dataset:
The quality of the results is enhanced by the fact that this document equates the impact of compressive concrete strengths of less than 25 MPa.
Pouzdanosti rezultata pogoduje činjenica da se odredbama u prikazanoj britanskoj normi izjednačava utjecaj tlačnih čvrstoća manjih od 25 MPa.
The ACI 318 regulation, with the control section proposed at the distance of 1.0d from the edge of the column, gives much better results than the standard ACI regulation.
Odredbe američke norme ACI 318, s prijedlogom da se kontrolni presjek uzme na razmaku 1,0 d od ruba stupa, daju dosta bolje rezultate u odnosu na standardne ACI preporuke.
In fact, with this proposal, the results offered by ACI 318 are generally quite good (Fs are in the range of 1,16 to 2,02), although it may broadly be stated that it underestimate the influence of the compressive strength of concrete.
Štoviše, s tim prijedlogom ACI daje, cjelovito gledano, veoma dobre rezultate (Fs je u granicama od 1,16 do 2,02) osim što se generalno može reći da podcjenjuje utjecaj tlačne čvrstoće betona.
Russian regulations СНиП - 84 provide very good results, with the Fs ranging from 1,28 to 2,16, and so it can be concluded that they are on an equal footing with much more recent regulations.
Ruski propis СНиП - 84 daje vrlo solidne rezultate tako da je Fs u granicama od 1,28 do 2,16, na osnovi čega se može zaključiti da je ravnopravan i sa znatno novijim propisima.
It takes properly into account the increase in punching capacity with an increase in depth of the footings, while it underestimates the influence of the concrete tensile strength for higher class types of concrete.
Dobro prati povećanje nosivosti na proboj s povećanjem visine temelja, ali podcjenjuje utjecaj vlačne čvrstoće za betone većih marki.
Calculations according to BAB 87 provide results that are characterized by high values of the coefficient Fs, and by considerable scattering of results, from 3,08 to 4,39.
Proračun prema Pravilniku BAB 87 daje rezultate koje karakteriziraju visoke vrijednosti koeficijenta Fs i njihovo rasipanje koje je u granicama od 3,08 do 4,39.
The proposed/modified design procedure gives the best results because the coefficient Fs values are closest to one, and dispersion values of Fs are relatively low (0,95 - 1,41).
Predloženi (modificirani) postupak proračuna daje najbolje rezultate jer su vrijednosti koeficijenta Fs najbliže jedinici i pokazuju relativno malo rasipanje vrijednosti Fs, tj. vrijednosti su između 0,95 i 1,41).
All regulations analysed in this text (except BAB 87) use partial safety factors for loads and materials, which significantly differ from one another.
U svim analiziranim propisima (osim BAB 87) uzeti su u obzir parcijalni koeficijenti sigurnosti za opterećenje i materijale, a oni se međusobno znatno razlikuju.
Considering the above mentioned differences, and the fact that some regulations use additional safety factors in relation to the type of stress state or working conditions (BS, ACI, СНиП), it is possible to make an analysis that would invalidate or annul the mentioned differences.
S obzirom na spomenute međusobne razlike, kao i činjenicu da se u nekim propisima koriste i dodatni koeficijenti sigurnosti koji se odnose na vrstu stanja naprezanja ili uvjete rada (BS, ACI, СНиП), moguće je napraviti i analizu koja bi osporila spomenute razlike.
Fsu - total safety factor, γo - safety factor for load, γm - safety factor for material, γn.
Fsu - ukupni koeficijent sigurnosti, γo - koeficijent sigurnosti za opterećenje, γm - koeficijent sigurnosti za materijal, γn.
s. - safety factor for the corresponding stress state, γu.
s. - koeficijent sigurnosti za odgovarajuće stanje naprezanja, γu.
r. - safety factor for working conditions.
r. - koeficijent sigurnosti za uvjete rada.
Usually, the participation of live load in relation to the dead load in buildings amounts to approximately 15 %, and so the global safety factor for load can be calculated for all regulations as follows:
Kad je riječ o zgradama, uobičajeni udio povremenog opterećenja u odnosu na stalno opterećenje približno je 15 %, tako da se općeniti koeficijent sigurnosti za opterećenje, u svakom od propisa, može odrediti na sljedeći način:
Regulation
Propis
Load - γ0
Opterećenje - γ0
Material - γm
Materijal - γm
Stress state
Stanje naprezanja
Working conditions
Uvjeti rada
Dead
stalno
Live
povremeno
Global
općenito
Reinforcement steel
armaturni čelik
Partial safety factors used in some regulations
Parcijalni koeficijenti sigurnosti prema pojedinim propisima
However, in order to obtain ultimate punching loads, material safety coefficients equalling to one are used in this text.
Ti su koeficijenti također uzeti s vrijednošću 1,0 pri proračunu graničnih sila loma.
These coefficients were also assumed to be equal to 1,0 in the calculation of the ultimate punching load.
Uzimajući sve to u obzir, ukupni su koeficijenti sigurnosti pri proboju (Fsu) za pojedine propise određeni i prikazani u tablici 6.
Considering that ultimate punching loads are calculated based on actual rather than calculated characteristics of the material (concrete), the service load can be obtained for some regulations by dividing the calculated ultimate punching load by total safety factors given in Table 6.
Radi uvida u pouzdanost rezultata koje daju pojedini propisi, potrebno je usporediti stvarne koeficijente sigurnosti prikazane u tablici 7. i ukupne koeficijente sigurnosti pri proboju određene u pojedinom propisu prikazane u tablici 6.
To gain a proper insight into the quality of results provided by the studied regulations, the actual safety coefficients given in
vrijednosti za Fss u rasponu od 1,48 za temelj TX (što je na strani nesigurnosti) do 4,52.
Thus, values Fss range from 1,48 for the footing TX (which is on the side of safety) to 4,52.
Njemački DIN 1045-1 iz 2008., zasnovan na EC 2, daje konzervativnije rezultate u odnosu na EC 2, tako da se za stvarne koeficijente sigurnosti dobivaju vrijednosti od 4,09 do čak 7,55.
However, if suggestions given in the ECP are used, this regulation gives much better results, i.e. the range of Fss values is smaller (2,05 - 3,79) and all the results are on the safe side.
Britanski propis BS 8110 također je vrlo konzervativan, tako da su na osnovi njega dobiveni stvarni koeficijenti sigurnosti u rasponu 3,01 do 7,00, što je znatno više u odnosu na ukupni koeficijent sigurnosti pri proboju koji je prema tom propisu
The regulation DIN 1045-1, which is based on EC2, provides results that are more conservative compared to EC 2, and so the values ranging from 4,09 to 7,55 are obtained for actual safety coefficients.
Preporuke američkog propisa ACI 318-02 također daju vrlo konzervativne rezultate (Fss je u rasponu 4,41 do 7,29 u odnosu na Fsu = 2,18).
The regulation BS 8110 is also very conservative, and actual safety coefficients based on this regulations range from 3,01 - 7,00, which is much more when compared to the total safety coefficient at punching which amounts to 2,68 according to this regulation/standard.
Međutim, prijedlog da se prema tom propisu kontrolni presjek uzme na udaljenosti 1,0 d od ruba stupa daje racionalnije rezultate, tako da je Fss u rasponu od 2,53 do 4,41.
Results provided by ACI 318-02 recommendations are also highly conservative (Fss ranges from 4,41 to 7,29, as related to the Fsu = 2,18).
Rezultati dobiveni primjenom ruskog propisa СНиП-a 2.04.01-84 također su konzervativni, a vrijednosti za Fss su u rasponu od 2,44 do 4,17.
However, the suggestion that this regulation should place the control section at the distance of 1,0 d from the edge of column gives more rational results, and in this case the Fss ranges from 2,53 to 4,41.
Na osnovi ove usporedbe Pravilnik BAB 87 daje najkonzervativnije rezultate, tako da su vrijednosti za Fss kod svih temelja vrlo velike, čak do 7,75.
Results obtained by СНиП 2.04.01-84 are also conservative and Fss values range from 2,44 to 4,17.
To je i očekivano jer se jedini zasniva na konceptu dopuštenih napona.
This could have been expected as this is the
Međutim,
Total safety factors at punching for some regulations
Ukupni koeficijenti sigurnosti pri proboju prema pojedinim propisima
Normal exploitation force in column for some regulations, in kN
Vrijednosti normalne sile u stupu prema pojedinim propisima izražene u kN
ACI 318-02 СНиП 2,04,01-84 Proposed procedure
ACI 318-02 СНиП 2.04.01-84 Predloženi postupak
EC2 based on ECP [25]
EC2 na osnovu ECP [25]
Proposed procedure
Predloženi postupak
Measured
Rezultati ispitivanja
However, here it should be noted that there is still room for improvement of the proposed method, as the influence of the percentage of reinforcement on the punching bearing capacity has not been considered in the experimental research.
i ovdje treba imati na umu da postoji prostor za poboljšanje predloženog postupka, s obzirom na to da u provedenim eksperimentalnim istraživanjima nije razmatran utjecaj postotka armiranja na nosivost temelja na proboj.
The results would be even more accurate it this parameter were introduced.
Njegovim uvođenjem dobili bi se pouzdaniji rezultati.
7. Final remarks and conclusions
7. Zaključak
Based on the analysis presented in the paper, it can be concluded that all current regulations give conservative results, and that the most rational result is provided by EC 2, when the procedure proposed in the ECP is used [25].
Na osnovi provedene analize može se zaključiti da svi sadašnji propisi daju konzervativne rezultate, a među njima je najracionalniji EC 2 uz upotrebu postupka predloženog u ECP [25].
The results clearly point to the need for improvement - corrections to existing regulations - because the footing bearing capacity values based on these regulations are significantly underestimated, and so the actual coefficients Fss go up to 7,55.
Rezultati jasno upućuju na potrebu unapređenja - korigiranja postojećih propisa jer su u njima određene vrijednosti nosivosti temelja značajno podcijenjene, pa su vrijednosti stvarnih koeficijenata sigurnosti Fss dobiveni čak do 7,55.
The impact of various parameters used in the calculation of punching capacity of footings must therefore be reexamined, and the stress concentration factor must be introduced into the calculation.
Zbog toga je potrebno preispitati utjecaj pojedinih parametara u proračunu nosivosti temelja na proboj i uvesti u proračun koeficijent koncentracije napona.
The necessity of introducing this parameter in the punching calculation is further evidenced by the measurement of contact pressures in this and in previous experiments.
Nužnost uvođenja ovog parametra u proračun proboja je nesporna što pokazuju mjerenja kontaktnih pritisaka u ovom ekperimentu kao i u prijašnjima.
The number of footings tested on real soil is too small to formulate general conclusions.
Broj ispitivanih temelja na realnom tlu je mali da bi se formulirali opći zaključci.
Therefore, a more detailed parametric study must be conducted to determine the influence of the stress concentration factor and other parameters that are introduced in calculation of the punching bearing capacity of footings.
Zato bi bilo potrebno provesti detaljnije parametarske studije o utjecaju koeficijenta koncentracije i ostalih parametara koji se uvode u proračun nosivosti na proboj temelja.
This opens an ample space for further experimental research in this area.
To ostavlja širok prostor za daljnja eksperimentalna istraživanja u ovom smjeru.
Following the analysis of tests presented in available literature, it is proposed that an approximate angle of 45° be adopted for punching through the footing.
Uzimanjem u obzir procjene pokusa iz literature predloženo je da se aproksimativno može usvojiti da je kut loma kroz temeljnu ploču oko 450.
In paper [3] the authors conclude that the density of sand does not affect distribution of contact stresses under the footing, and that the adoption of their uniform distribution provides a sufficient safety against column punching through footing.
U radu [3] zaključeno je da zbijenost pijeska ne utječe na raspodjelu kontaktnih naprezanja ispod temelja i da usvajanje njihove ravnomjerne raspodjele osigurava dovoljnu sigurnost od proboja stupa kroz ploču temelja.
A probabilistic approach to punching analysis is adopted in some studies.
Tako je vjerojatnost loma AB ploče temelja samca proučena
Since in practice the safety factor 3 is used for load, it is recommended that this factor be increased to 4 so that the probability of column punching through the plate can be less than 1,35 x 10-3.
Budući da se u praksi koristi koeficijent sigurnosti za nosivost 3, preporučeno je da on bude povećan na 4 kako bi vjerojatnost loma (proboja) stupa kroz ploču bila manja od 1.35x10-3.
The stress concentration factor Fc depends on the effective depth of the footing, and it is higher for lower effective depth values, and vice versa.
Koeficijent koncentracije naprezanja Fc ovisi o statičkoj visini temelja i veći je za temelje manje statičke visine, i obratno.
This factor is also dependent on the intensity of the applied force, and it tends to increase as the punching load is approached.
Taj koeficijent ovisi i o veličini primijenjene sile pa je utoliko veći ukoliko se približavamo sili loma.
It is also dependent on the type of soil.
Također, on ovisi i o vrsti tla.
Although the experiment was conducted on the gravel subgrade, it would also be appropriate to find out how the factor Fc changes when other subgrade types are used: sand, silt and clay.
U ovom radu pokus je proveden rađen na podlozi od šljunka, ali bi trebalo istražiti kako se koeficijent Fc mijenja kada su u pitanju ostale vrste podloge: pijesak, prašina i glina.
A larger number of experiments should be conducted on gravel subgrade so that the values of this factor could be considered relevant.
Svakako bi i na podlozi od šljunka trebalo napraviti veći broj eksperimenata kako bi dobivene vrijednosti ovog koeficijenta bile mjerodavne.
Therefore, a larger number of experiments and appropriate analyses should be made in order to determine the value of this factor with greater accuracy.
Dakle, radi određivanja preciznije vrijednosti ovog koeficijenta potrebno je napraviti veći broj eksperimenata i odgovarajućih analiza.
It is only then that adequate values of parameters for different soil types and different footing characteristics would be obtained, and these values could then be used in the design process.
Tek nakon toga mogle bi se odrediti mjerodavne vrijednosti ovog parametra za različite vrste tla i različite karakteristike temelja koje bi se kasnije mogle koristiti pri projektiranju.
This parameter is not further analysed in this paper; it is in fact given as an arithmetic mean obtained on the tested footings.
U ovom radu nije detaljnije analiziran taj parametar već je on dan kao aritmetička sredina dobivena na ispitivanim temeljima.
Theoretical models should be developed in further research, but with verification based on experimental results.
U daljnjim istraživanjima potrebno je razviti teorijske modele, ali uz verifikaciju na osnovi rezultata eksperimentalnih istraživanja.
The study of plates with a small shear span ratio is of special interest.
Posebno je važno ispitivanje ploča s malim odnosom raspona posmika i visine.
The application of high strength concrete in foundations involves examination of impact of the concrete compressive strength at punching [30].
Primjena betona visokih čvrstoća u temeljima iziskuje ispitivanje utjecaja njihove tlačne čvrstoće na ponašanje pri proboju [30].
The authors extend their thanks to professor Verka Prolović, professor Dragan Lukic, and Nebojsa Davidovic M.Sc., for their valuable assistance during experimental research conducted in the scope of the paper [18].
Autori rada zahvaljuju profesorima Verki Prolović i Draganu Lukiću i magistru Nebojši Davidoviću na svesrdnoj pomoći tijekom eksperimentalnih istraživanja u okviru rada [18].
The paper is the result of research conducted within projects TR 36028 and TR 36048, as financed by the Ministry of Education, Science and Technological Development of the Republic of Serbia.
Rad je nastao kao rezultat istraživanja na projektima TR 36028 i TR 36048 koje financira Ministarstvo prosvete, nauke i tehnološkog razvoja Republike Srbije.
[18] Bonić, Z.: A contribution to the failure calculation theory by punching shear of column footings resting on deformable subgrade soil, PhD thesis, Faculty of Civil Engineering and Architecture, Niš, Serbia, 2011, p. 182 (in Serbian).
[7] Sacramento, P.V.P, Ferreira, M.P., Oliveira, D.R.C., Melo, G.S.S.A.: Punching strength of reinforced concrete flat slabs without
[19] ACI Committee 318: Building Code Requirements for Structural Concrete (ACI 318-02) and Commentary (318R-02).
shear reinforcement, IBRACON Estruturas e Materials, Vol. 5,
Cement & Concrete Composites 24, 2002, p. 509-521.
under Concentrated Loads.
[22] Eurocode 2 (EN 1992): Design of Concrete Structures, Part 1.1: General Rules and Rules for Buildings, Brussels, 2004, 226 pp.
Proboj temelja samaca - usporedba proračuna i eksperimenta [9] Hegger, J., Ricker, M., Sheriff, A.G.: Punching strength of
[23] SNiP 2.03.01-84: Concrete and Reinforced Concrete Structures
reinforced concrete footings, ACI Structural Journal, September
Design Codes, Moscow, 1985, 77 pp. (in Russian).
October 2009, p. 706-716.
M.:
L.:
Journal of Advanced Technology, Vol. 6, No. 1, February 2008, pp.
Transverse Reinforcement, ACI Structural Journal, Vol. 106, No.
[29] Lu, W.Y.: Failure probabilities of reinforced concrete column
4, July-August, 2009, p. 485-494.
footings, Journal of the Chinese Institute of Engineers, Vol. 29,
[17] fib (International Federation for Structural Concrete)-Model
N0. 4, 2006, pp. 733-739.
Code 2010-Draft, Bulletins 55 and 56, 2010.
[6] Hallgren, M., Kinnunen, S., Nylander, B.: Punching shear tests on column footings, Nordic Concrete Research 21(1), 1998, p.1-24.
Concrete Institute, Farmington Hills, Mich., 2002, 443 pp. [20] Theodorakopoulos, D.D., Swamy, R.N.: Ultimate punching shear strength analysis of slab-column connections.
under Concentrated Loads.
Design Codes, Moscow, 1985, 77 pp. (in Russian).
Research and Development Bulletin
[24] CEB -FIP Model Code 1990.
D47, Illinois, 1913.
Comite Euro-International du beton,
[11] Staller, M.A.: Analytical studies and numerical analysis of punching shear failure in reinforced concrete slabs,
[28] Hamada, S., Yang, Q., Mao, M.: Evaluation of punching shear strength of reinforced concrete slabs based on database,
Int. Workshop on Punching Shear Capacity of RC Slabs, Stockholm
Journal of Advanced Technology, Vol. 6, No. 1, February 2008, pp.
[16] Fernadez, R.M., Muttoni, A.: Applications of the critical shear crack theory to punching of Reinforced Concrete Slabs with
[30] Ozden, S., Ersoy, U., Ozturan, T.: Punching shear tests of normaland high-strength concrete flat plates.
Models for estimating uniaxial compressive strength and elastic modulus
Modeli za procjenu jednoosne tlačne čvrstoće i modula elastičnosti
University of Zagreb
Zlatko Briševac, dipl. ing. rud.
Faculty of Mining, Geology and Petroleum Engineering zlatko.brisevac@rgn.hr
Sveučilište u Zagrebu Rudarsko-geološko-naftni fakultet zlatko.brisevac@rgn.hr
Prof. Petar Hrženjak, PhD. Min.
Petar Hrženjak, dipl. ing. rud.
Renato Buljan, PhD. Geol.
Renato Buljan, dipl. ing. geol.
Croatian Geological Surveyt renato.buljan@hgi-cgs.hr
Hrvatski geološki institut renato.buljan@hgi-cgs.hr
Key words: estimation, uniaxial compressive strength, Young's modulus, intact rock material
Ključne riječi: procjena, jednoosna tlačna čvrstoća, Yangov modul elastičnosti, intaktni stijenski materijal
Modeli za procjenu jednoosne tlačne čvrstoće i modula elastičnosti
Models for estimating uniaxial compressive strength and elastic modulus
U ovom radu ukratko je izložen pregled najznačajnijih metoda za procjenu jednoosne tlačne čvrstoće i Yangovog modula elastičnosti intaktnog stijenskog materijala koje su nastale u okviru mnogobrojnih istraživanja.
The most significant methods for estimating the uniaxial compressive strength and Young's modulus of intact rock material, formulated in the scope of numerous previous studies, are briefly presented in the paper.
Iznesen je prijedlog podjele metoda prema kojemu se one u osnovi mogu podijeliti na jednostavne i složene metode.
The proposal for classification of these methods, according to which they can generally be divided into simple and complex methods, is also presented.
Jednostavne metode uključuju različite dijagrame i tablice te primjenu jednadžbi jednostruke regresije, a složene metode uključuju primjene jednadžbi višestruke regresije, modela neizrazite logike, neuronskih mreža, evolucijskog programiranja i regresijskog stabla.
Simple methods include various diagrams and tables and the use of simple regression equations, while complex methods comprise the use of multiple regression equations, fuzzy logic models, neural networks, evolutionary programming, and regression trees.
Ključne riječi: procjena, jednoosna tlačna čvrstoća, Yangov modul elastičnosti, intaktni stijenski materijal
Key words: estimation, uniaxial compressive strength, Young's modulus, intact rock material
At that, and in addition to the density of materials, one of the most often defined properties is the uniaxial compressive strength (UCS), and the Young's modulus of elasticity (E).
Pri tome je, uz gustoću materijala, jedna od najodređivanijih značajki upravo jednoosna tlačna čvrstoća (UCS), a zatim i Youngov modul elastičnosti (E).
However, it often occurs that samples of the dimensions required for laboratory testing can not be extracted from such materials.
Međutim, čest je slučaj da iz takvih sredina nije moguće pripremiti uzorke odgovarajućih dimenzija za provedbu laboratorijskih ispitivanja.
That is why the need arose already at early stages of development of rock mechanics to determine the correlation of various physicomechanical properties of materials, so that one property can be estimated based of the value of another one.
Zbog toga se već u samim počecima razvoja mehanike stijena pojavila potreba za utvrđivanjem međuovisnosti između različitih fizikalno-mehaničkih značajki materijala kako bi se mogla provesti procjena jedne značajke na temelju vrijednosti druge.
These interdependencies have proven to be very useful in preliminary stages of the planning and design activities.
Te međuovisnosti pokazale su se vrlo korisnima u preliminarnim fazama planiranja i projektiranja.
2. Estimate models
2. Modeli procjene
Tables and diagrams
Tablice i dijagrami
The strength index determined by point load test can assist in this estimate.
Dijagram međuovisnosti UCS s gustoćom poroznosti i brzinom prolaska ultrazvučnih valova za vapnence, [2]
Field identification
Terenska identifikacija
Rock types
Primjeri
> 10 Specimen can only be pull apart by a geological hammer
> 10 Komad materijala je moguće otkinuti jedino uz pomoć geološkog čekića.
fresh basalt, chert, diabase, gneiss, granite, and quartzite
svježi bazalt, čert, dijabaz, gnajs, granit, kvarc
amphibiolite, sandstone, basalt, gabbro, gneiss, granodiorite, limestone, marble, rhyolite, and tuff
anfibolit, pješčenjak, bazalt, gabro, gnajs, tuf, grandiorit, peridotit, riolit
limestone, marble, sandstone, and schist
vapnenac, mramor, pješčenjak, škriljavac
Medium strong rock 25 - 50 1 - 2
Srednje čvrsta
Cannot be scraped or peeled with a pocket knife; specimen can be fractured with a single firm blow of a geological hammer.
Materijal se ne može zagrepsti ili ljuštiti džepnim nožićem, jedino ga je moguće razlomiti jednim udarcem geološkog čekića.
phyllite, schist, siltstone
filit, škriljavac, prahovnjak
Weak rock 5 - 25
Slaba
Can be peeled by a pocket knife with difficulty; shallow indentations made by firm blow with a point of geological hammer.
Materijal se može ljuštiti džepnim nožem, a čvrstim udarcem vrhom geološkog čekića nastaju plitke udubine.
chalk, rock salt, claystone, marl, siltstone, schist
kreda, glinjak, lapor, prahovnjak, škriljavac, kamena sol
Weak rok
Vrlo slaba
- Crumbles under firm blows with point of geological hammer; can be peeled by pocket knife
- Materijal se mrvi uslijed jakog udarca geološkim čekićem, može ga se ljuštiti džepnim nožem.
highly weathered or altered rock, schist
jako istrošene ili alterirane stijene, škriljavac