OMITTING THE STATIC COMPONENT FROM DESIGN DYNAMIC MODELS OF PEDESTRIAN LOAD

In current codes and guidelines for pedestrian bridge design, the vibration serviceability requirement is determined as a pedestrian comfort criteria, by assessing the maximum acceptable acceleration of any part of the bridge deck, but these criteria can also be defined as the maximum acceptable deflection or velocity at the most unfavorable part of the bridge deck. The design models of dynamic pedestrian load for serviceability limit state (SLS) verification are based on experimental models of dynamic pedestrian load; however, design models of vertical pedestrian load omit the static component of pedestrian weight. In this study, we compare the dynamic responses of different single-span bridge decks, each with a resonance frequency of 2 Hz. We show that omitting the static component is appropriate when defining the comfort criteria by using the maximum acceptable bridge deck velocity or acceleration

Reduction in wind force in relation to corner design of bridge piers

The effects of wind on beam bridges can be significantly reduced with careful design of deck, roadway and wind barriers, as well as with appropriate design of piers. In this paper, the influence of corner design of rectangular cross-sectional piers to total wind force on piers is investigated. The total wind force changes, due to a different corner design of rectangular cross section of piers in free standing phase, are analyzed for piers of different heights, different environments and different wind velocities. The correlation between changes in total wind force and changes in geometric properties of a pier is also shown. By rounding the corners of a pier square cross section, the total wind force on pier in free standing phase can be drastically reduced in comparison to the total wind force on sharp corner pier with a small reduction in a load bearing properties of the pier. Changes in the bridge pier environment, as well as changes in pier height and wind velocity have negligible influence on changes in reduction of total wind force due to rounding the pier corners

Novo građevinsko tehničko zakonodavstvo u Hrvatskoj

U radu je dan osvrt na osnovne zakone i podzakonske akte koji reguliraju područje graditeljstva, a osiguravaju ujednačavanje hrvatskog s europskim tehničkim zakonodavstvom u području graditeljstva. Također je uspostavljena veza između pojedinih zakona i podzakonskih akata. U radu je posebno obrađeno područje tehničkih propisa i hrvatskih normi za građevne proizvode, projektiranje, građenje i održavanje građevina koji su izrađeni u skladu s novim građevinskim tehničkim zakonodavstvom koje se temelji na ispunjavanju bitnih zahtjeva za građevinu i Direktivi o građevnim proizvodima. Objašnjena je razlika između obvezne i neobvezne primjene hrvatskih normi na koje upućuju tehnički propisi. Na kraju rada je dan sažeti tablični prikaz važećih tehničkih propisa iz područja graditeljstva sa pripadnim područjem primjene i izuzecima na koje se ne odnosi ili ne primjenjuje pojedini tehnički propis i broj hrvatskih normi na koje izravno upućuju važeći tehnički propisi

Serviceability verification of pedestrian bridges under pedestrian loading

Pješački promet može izazvati značajne vibracije vitkih pješačkih mostova. U proteklih nekoliko desetljeća mnogi se znanstvenici bave problemom pouzdanog predviđanja dinamičkog odgovora (vibriranja) mostova izazvanog ljudskim kretanjem. Većina normi za projektiranje mostova definira određene kriterije koje je potrebno zadovoljiti da bi bilo dokazano granično stanje uporabljivosti vezano uz vibriranje. Osnovni nedostatak važećih europskih normi (Eurokodova) je nedostatak definiranih modela pješačkih opterećenja za koja se provodi dokaz graničnog stanja uporabljivosti vezanog uz vibriranje. U radu je predložen postupak proračuna pješačkih mostova (s preporučenim modelima pješačkog opterećenja) u području graničnog stanja vibracija uzrokovanih pješačkim opterećenjem. Koristeći predloženi postupak proveden je dokaz graničnog stanja uporabljivosti na modelu armiranobetonskog pješačkog mosta u parku Maksimir u Zagrebu.Due to their slenderness, pedestrian bridges may vibrate significantly under pedestrian traffic. Many researches in the past few decades deal with the problem of predicting the vibration response induced by human activity reliably. Most of the codes in the field of footbridge design define certain pedestrian comfort criteria which have to be satisfied to fulfil the serviceability in relation to vibration. The main disadvantage of the current European codes (Eurocodes) is lack of defined dynamic models of pedestrian loads for the serviceability state verification in relation with vibration. In this paper a design procedure (with load models recommendation) for verification of the serviceability limit state related to vibration due to pedestrians is proposed. According to the proposed procedure the serviceability verification on a model of a reinforced concrete pedestrian bridge in the Maksimir Park in Zagreb is conducted