Skewed bridges have exhibited poorer performance during lateral earthquake loading in comparison to non-skewed bridges (Apirakvorapinit et al. 2012; Elnashai et al. 2010). Results from numerical modeling by Shamsabadi et al. (2006), small-scale laboratory tests by Rollins and Jessee (2012), and several large-scale tests performed by Rollins et al. at Brigham Young University (Franke 2013; Marsh 2013; Palmer 2013; Smith 2014; Frederickson 2015) led to the proposal of a reduction curve used to determine a passive force skew reduction factor depending on abutment skew angle (Shamsabadi and Rollins 2014). In all previous tests, a uniform longitudinal load has been applied to the simulated bridge abutment. During seismic events, however, it is unlikely that bridge abutments would experience pure longitudinal loading. Rather, an inclined loading situation would be expected, causing rotation of the abutment backwall into the backfill. In this study, a large-scale test was performed where inclined loading was applied to a 30 skewed bridge abutment with sand backfill and compared to a baseline test with uniform loading and a non-skewed abutment. The impact of rotational force on the passive resistance of the backfill and the skew adjust factor was then evaluated. It was determined that inclined loading does not have a significant effect on the passive force skew reduction factor. However, the reduction factor was somewhat higher than predicted by the proposed reduction curve from Shamsabadi and Rollins 2014. This can be explained by a reduction in the effective skew angle caused by the friction between the side walls and the back wall. The inclined loading did not change the amount of movement required to mobilize passive resistance with ultimate passive force developing for displacements equal to 3 to 6% of the wall height. The rotation of the pile cap due to inclined loading produced higher earth pressure on the obtuse side of the skew wedge, as was expected.These findings largely resolve the concern that inclined loading situations during an earthquake may render the proposed passive force skew reduction curve invalid. We suggest that the proposed reduction curve remains accurate during inclined loading and should be implemented in current codes and practices to properly account for skew angle in bridge design.

Skewed bridges have exhibited poorer performance during lateral earthquake loading when compared to non-skewed bridges (Apirakvorapinit et al. 2012; Elnashai et al. 2010). Results from small-scale laboratory tests by Rollins and Jessee (2012) and numerical modeling by Shamsabadi et al. (2006) suggest that skewed bridge abutments may provide only 35% of the non-skewed peak passive resistance when a bridge is skewed 45°. This reduction in peak passive force is of particular importance as 40% of the 600,000 bridges in the United States are skewed (Nichols 2012). Passive force-deflection results based on large-scale testing for this study largely confirm the significant reduction in peak passive resistance for abutments with longitudinal reinforced concrete wingwalls. Large-scale lateral load tests were performed on a non-skewed and 45° skewed abutment with densely compacted sand backfill. The 45° skewed abutment experienced a 54% reduction in peak passive resistance compared to the non-skewed abutment. The peak passive force for the 45° skewed abutment was estimated to occur at 5.0% of the backwall height compared to 2.2% of the backwall height for the non-skewed abutment. The 45° skewed abutment displayed evidence of rotation, primarily pushing the obtuse side of the abutment into the backfill, significantly more than the non-skewed abutment as it was loaded into the backfill. The structural and geotechnical response of the wingwalls was also monitored during large-scale testing. The wingwall on the obtuse side of the 45° skewed abutment experienced nearly 6 times the amount of horizontal soil pressure and 7 times the amount of bending moment compared to the non-skewed abutment. Pressure and bending moment distributions are provided along the height of the wingwall and indicate that the maximum moment occurs approximately 20 in (50.8 cm) below the top of the wingwall. A comparison of passive force per unit width suggests that MSE wall abutments provide 60% more passive resistance per unit width compared to reinforced concrete wingwall and unconfined abutment geometries at zero skew. These findings suggest that changes should be made to current codes and practices to properly account for skew angle in bridge design.

Passive force-deflection behavior for densely compacted backfills must be considered in bridge design to ensure adequate resistance to both seismic and thermally induced forces. Current codes and practices do not distinguish between skewed and non-skewed bridge abutment geometries; however, in recent years, numerical models and small-scale, plane-strain laboratory tests have suggested a significant reduction in passive force for skewed bridge abutments. Also, various case studies have suggested higher soil stresses might be experienced on the acute side of the skew angle. For these reasons, three large-scale tests were performed with abutment skew angles of 0, 15 and 30 degrees using an existing pile cap [11-ft (3.35-m) wide by 15-ft (4.57-m) long by 5.5-ft (1.68-m) high] and densely compacted sand backfill confined by MSE wingwalls. These tests showed a significant reduction in passive force (approximately 38% as a result of the 15 degree skew angle and 51% as a result of the 30° skew angle. The maximum passive force was achieved at a deflection of approximately 5% of the backwall height; however, a substantial loss in the rate of strength gain was observed at a deflection of approximately 3% of the backwall height for the 15° and 30° skew tests. Additionally, the soil stiffness appears to be largely unaffected by skew angle for small displacements. These results correlate very well with data available from numerical modeling and small-scale lab tests. Maximum vertical backfill displacement and maximum soil pressure measured normal to the skewed backwall face were located on the acute side of the skew for the 15° and 30° skew test. This observation appears to be consistent with observations made in various case studies for skewed bridge abutments. Also, the maximum outward displacement of the MSE wingwalls was located on the obtuse side of the skew. These findings suggest that changes should be made to current codes and practices to properly account for skew angle in bridge design.

Bridge abutments are designed to withstand lateral pressures from thermal expansion and seismic forces. Current design curves have been seen to dangerously over- and under-estimate the peak passive resistance and corresponding deflection of abutment backfills. Similar studies on passive pressure have shown that passive resistance changes with different types of constructed backfills. The effects of changing the length to width ratio, or including MSE wingwalls determine passive force-deflection relationships. The purpose of this study is to determine the effects of the wall heights and of the MSE support on passive pressure and backfill failure, and to compare the field results with various predictive methods. To compare the effects of backfill geometries, three large-scale tests with dense compact sand were performed with abutment backfill heights of 3 ft (0.91 m), 5.5 ft (1.68 m), and 5.5 ft (1.68 m) confined with MSE wingwalls. Using an existing pile cap 11 ft (3.35 m) wide and 5.5 ft (1.68 m) high, width to height ratios for the abutment backfills were 3.7 for the 3ft test, and 2.0 for the 5.5ft and MSE tests. The failure surface for the unconfined backfills exhibited a 3D geometry with failure surfaces extending beyond the edge of the cap, increasing the "effective width", and producing a failure "bulb". In contrast, the constraint provided by the MSE wingwalls produced a more 2D failure geometry. The "effective width" of the failure surface increased as the width to height ratio decreased. In terms of total passive force, the unconfined 5.5ft wall provided about 6% more resistance than the 5.5ft MSE wall. However, in terms of passive force/width the MSE wall provided about 70% more resistance than the unconfined wall, which is more consistent with a plane strain, or 2D, failure geometry. In comparison with predicted forces, the MSE curve never seemed to fit, while the 3ft and 5.5ft curves were better represented with different methods. Even with optimizing between both the unconfined curves, the predicted Log Spiral peak passive forces were most accurate, within 12% of the measured peak resistances. The components of passive force between the unconfined tests suggest the passive force is influenced more by frictional resistance and less by the cohesion as the height of the backwall increases.

To investigate the passive force-displacement relationships provided by a transitional zoned backfill consisting of cement treated aggregate (CTA) and compacted gravel, a series of full-scale lateral abutment load tests were performed. The transitional zoned backfill was designed to minimize differential settlement adjacent to bridge abutments for the California High Speed Rail project. Tests were performed with a 2-D or plane strain backfill geometry to simulate a wide abutment. To investigate the effect of skew angle on the passive force, lateral abutment load tests were also performed with a simulated abutment with skew angles of 30º and 45º. The peak passive force developed was about 2.5 times higher than that predicted with the California HSR design method for granular backfill material with a comparable backwall height and width. The displacement required to develop the peak passive force decreased with skew angle and was somewhat less than for conventional granular backfills. Peak passive force developed with displacements of 3 to 1.8% of the wall height, H in comparison to 3 to 5% of H for conventional granular backfills.The skew angle had less effect on the peak passive force for the transitional backfill than for conventional granular backfills. For example, the passive force reduction factor, Rskew, was only 0.83 and 0.51 for the 30º and 45º skew abutments in comparison to 0.51 and 0.37 for conventional granular backfills. Field measurements suggest that the CTA backfill largely moves with the abutment and does not experience significant heave while shear failure and heaving largely occurs in the granular backfill behind the CTA backfill zone.

I städer finns det idag många bortglömda outnyttjade platser, så kallade ickeplatser,vars fulla potential inte tillvaratas. Stadens sociala hållbarhet missgynnas ofta av dessaplatser som i många fall ger upphov till otrygghet, obehag och utsatthet för förbipasserande,särskilt för kvinnor. Återkommande bortglömda platser i svenska städerär de så kallade brofästeplatserna, det vill säga platser under broar intill brofästen.Syftet med studien är att visa på potentialen hos outnyttjade brofästeplatser i urbanamiljöer och att belysa förutsättningar, problem och möjligheter samt sociala och ekologiskafördelar med en bebyggelse av dessa platser.Studien visar att bebyggelse av platserna kan skapa säkra och inkluderande områdenatt vistas i, samt öka den upplevda tryggheten på platsen framförallt för kvinnor.Bebyggelse som i någon form aktiverar platsen bidrar till att skapa sociala möten istaden. Bebyggelsen kan även fungera brottsförebyggande, bland annat till följd avett ökat flöde av människor på platsen. Ekologiska fördelar som erhålls är att urbangrönska, och därmed viktiga ekosystemtjänster, kan bevaras i större utsträckning dåde redan hårdgjorda eller grusbelagda ytorna används vid förtätning i urbana miljöeristället för grönområden. Grönska och ekosystemtjänster ger viktiga rekreativa ochsociala värden för stadens invånare och gynnar även förekomsten av biologisk mångfald.Brofästeplatser utnyttjas i andra länder både för bostäder och verksamheter, därföruppstår frågan om varför dess potential inte tillvaratas i Sverige. Platserna tycks haglömts bort eller tidigare inte behövt tas i beaktning vid förtätning av svenska städer,då det funnits annan mark att exploatera. Studien konstaterar att det inte finns någragenerella förbud eller reglemente som reglerar bebyggelse eller icke bebyggelse avbrofästeplatser. Samtliga lagar, krav och bestämmelser vilka gäller vid planering, projekteringoch uppförande av byggnader i Sverige, gäller för platserna. Varför platsernainte nyttjats kan även bero på förutfattade meningar hos aktörer i byggbranschen.Exempelvis förutsätts att krav inom andra områden än det egna inte uppnås. De förutfattademeningarna är ofta grundade i antaganden utanför respektive yrkesprofession,snarare än fakta, vetskap och erfarenhet. För att platserna ska kunna bebyggas krävsdärmed en förändring av inställning och attityd hos aktörer i branschen.Byggnadstypologierna verksamhetslokaler, bostäder och tillfälliga boenden, är allamöjliga att uppföra vid brofästeplatser, med undantag för bostäder vid de brofästeplatserdär ljudnivå och dagsljusinsläpp inte uppnår kraven. Bäst lämpade byggnadstypologiför många urbana brofästeplatser är verksamhetslokaler, där en blandningav funktioner som både kräver konsumtion och inte kräver konsumtion skulle gynnaden sociala hållbarheten i området bäst. Studien visar att bebyggelse av brofästeplatserär möjlig om parametrar som belysts i studien beaktas och tillgodoses. För attmöjliggöra ett sådant projekt krävs en ändrad inställning, attityd och ett gediget tvärprofessionelltsamarbetemellan olika professioner i branschen. Att myndigheter ochaktörer inom byggbranschenskapar ett bättre samarbete skulle inte enbart gynna eneventuell bebyggelse av dessa platser, utan samtliga byggprojekt i Sverige. / In today’s cities there are many forgotten places whose full potential is not being met.The social sustainability of the city is often disadvantaged by these places as theycause insecurity, discomfort and vulnerability to passers-by, especially women. Aforgotten place that is recurring in Swedish cities are so-called bridge abutment-sites,that is, places under bridges next to the abutment. The purpose of the study is todemonstrate the potential of these non-places at bridge abutments in urban environmentsand to highlight the conditions, problems and possibilities as well as the socialand ecological benefits of a development of these sites.The study shows that building these sites can create safe and inclusive areas to stayin, as well as increase the perceived security of the site, especially for women. Housingthat in some way activates the site helps to create social meetings in the city. Thebuilding can also act crime preventive, partly due to an increased flow of people onthe site. The ecological benefits obtained are that urban greenery, and thus importantecosystem services, can be preserved to a greater extent as already impermeable surfacesare used in densification in urban environments instead of green areas. Greeneryand ecosystem services provide important recreational and social values for the city’sinhabitants and also benefit the presence of biodiversity.All laws, requirements and regulations that apply to planning, design and constructionof buildings in Sweden, also applies to these locations. The study finds that there areno general prohibitions or regulations that regulate the construction or non-constructionof bridge abutments. Bridge abutment-sites seem to have been forgotten or previouslynot needed to be taken into account in the densification of Swedish cities, sincethere have been other land to exploit. Another reason why the sites have not been usedis due to preconceived opinions in the construction industry. The preconceptions areoften based on assumptions beyond professional knowledge, rather than facts andexperience. In order for the places to be built, a change of attitude in operators in theconstruction industry is required.The function-types of community center, housing and temporary accommodationare all possible to construct at these sites, with the exception of housing at the bridgeplaces where noise levels and daylight emissions do not meet the requirements. Thebest-suited function-type for many urban bridge abutment-sites is a communitycenter, where a mix of functions that require both consumption and non-consumptionwould best benefit social sustainability in the area.The study shows that construction of the bridge abutment-sites is possible if parameters,as mentioned in the study, are considered and met. In order to enable such aproject, a change in attitude and solid cooperation between several operators in theindustry are required. The cooperation between authorities and operators in the constructionindustry would not only benefit the possible development of these sites, butall construction projects in Sweden.

The aim of this diploma thesis is to design and assess highway bridge. The structure is located on the D1 motorway section bridging a wide valley between the Slovak villages Doľany a Klčov. Three variants have been created – box girder bridge with transverse overhangs, a pair of girder bridge and a pair of box girder bridges. The various proposals were compared with each other. For the most valuable option is selected prestressed box girder bridge with transverse overhangs, which are supported by prefabricated concrete struts. The selected proposal was subsequently elaborated in detail, the load-bearing structure is analyzed using Scia Engineer 16. In calculating the internal forces is adjusted for the effects of construction methods, even as time-dependent analysis TDA. When designing the load-bearing structure it is considered the action of permanent load, also loading from transport and temperature. The structure is assessed for serviceability and ultimate limit states according to current standards. The bridge deck is built by incremental launching method. The principle of this method consists of building the segments in a casting yard located behind the bridge abutment. Each segment is matchcast against the previous one and prestressed to the section of structure already built. The whole superstructure is then jacked forward a distance equal to the length of this segment. This process is repeated until the bridge deck is in its final position. Chosen method of construction is very fast and efficient, to the country in the valley isn´t damage during construction.