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Full-Scale Shake Table Cyclic Simple Shear Testing of Liquefiable SoilJacobs, Jasper Stanford 01 February 2016 (has links) (PDF)
This research consists of full-scale shake table tests to investigate liquefaction of sandy soils. Consideration of the potential and consequences of liquefaction is critical to the performance of any structure built in locations of high seismicity underlain by saturated granular materials as it is the leading cause of damage associated with ground failure. In certain cases the financial losses associated with liquefaction can significantly impact the financial future of an entire region.
Most liquefaction triggering studies are performed in the field where liquefaction has been previously observed, or in tabletop laboratory testing. The study detailed herein is a controlled laboratory test performed at full scale to allow for the measurement of field-scale index testing before and after cyclic loading. Testing was performed at the Parson’s geotechnical and Earthquake Laboratory at Cal Poly San Luis Obispo on the 1-dimensional shake table with a mounted flexible walled testing apparatus. The testing apparatus, originally constructed for soil-structure interaction experiments utilizing soft clay was retrofitted for the purpose of studying liquefaction.
This research works towards comparing large-scale simple-shear liquefaction testing to small-scale simple-shear liquefaction testing of a #2/16 Monterey sand specimen. The bucket top was modified in order to apply a vertical load to the soil skeleton to replicate overburden soil conditions. Access ports were fitted into the bucket top for instrument cable access and to allow cone penetration testing before and after cyclic loading. A shear-wave generator was created to propagate shear waves into the sample for embedded accelerometers to measure small strain stiffness of the sample. Pore-pressure transducers were embedded in the soil sample to capture excess pore water pressure produced during liquefaction. Displacement transducers were attached to the bucket in order to measure shear strains during cyclic testing and to measure post-liquefaction volumetric deformations.
The results of this investigation provide an empirical basis to the behavior of excess pore water production, void re-distribution, shear wave velocity, shear strain and cone penetrometer tip resistance of #2/16 Monterey sand before, during, and after liquefaction in a controlled laboratory environment at full-scale.
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Performance of a Stormwater Filter and Bacteria Inactivation Using Biocidal MediaBowerman, Alexander Scott 01 March 2010 (has links) (PDF)
There are many possible ways to mitigate stormwater pollution, but this study focused on the DrainPacTM catchment basin insert and the feasibility of integrating N-halamine biocidal brominated beads into the filter system. This study was divided into three sections. The first section involved testing a DrainPacTM filter for treatable flow rates, head loss, and removal of solids, oil, and bacteria. The DrainPacTM filter is designed to be installed in a stormwater catch basin. The filter is composed of a 12 x 41 inch metal frame with textile filter media attached to it in a basket shape. The upper portion of one panel of the filter basket is made from a plastic mesh to allow overflow if the filter is overloaded. The second section of this study involved testing N-halamine brominated biocidal beads in laboratory-scale columns, and the third section involved integrating the beads into the DrainPacTM filter and testing it full scale.
For the DrainPacTM filter tests, the unit was installed into a custom-built test flume which was designed to mimic the conditions that would be encountered in a real stormwater application. The flume was supplied with a gravity-fed stream of water from a retention pond located on the Cal Poly, San Luis Obispo campus. The initial tests were conducted to determine the amount of head loss produced by the filter. First, the clean filter was subjected to flow rates between 20 and 200 GPM. The filter showed very minimal head loss (0.5 to 9.1 cm for 20 to 200 GPM) when not loaded with solids. Next, the filter was subjected to 200 GPM flow with a solids concentration of between 80 and 100 mg/L until it failed (overflowed). This occurred after 625 g of solids had been added to the filter. After the filter had been loaded with solids to the point of overflow at 200 GPM, it was tested to determine what flow rate could be filtered with the solids present. The fully loaded filter was able to pass a flow rate of up to 80 GPM before overflowing.
The DrainPacTM filter removed solids at a range of efficiencies from 83 to 91% at flow rates between 20 and 200 GPM. The higher removal efficiencies were achieved at the lower flow rates. The filter removed oil at efficiencies ranging between 40 and 80%. The oil removal efficiency did not appear to depend on the flow rate. The DrainPacTM filter did not remove bacteria under the test conditions.
Following the DrainPacTM experiments, 0.3 mm and 0.8 mm diameter N-halamine brominated biocidal beads were tested in the lab using a laboratory glass column. At flow rates between 0.28 and 1.4 mL/sec, a 1 cm bed height of the 0.3 mm beads was found to produce head losses between 19 and 51.7 cm. The 0.8 mm beads produced head losses ranging from 11.9 to 47.7 cm when tested over the same range of flow rates. These flow rates represent nominal velocities between 0.36 and 1.8 cm/sec which would be expected in the DrainPacTM filter. The beads were then tested to determine how effectively they inactivate bacteria in a stream of water. Contact time after flowing through the column was found to be the key factor in how efficiently the beads worked. When the effluent samples were instantly quenched with sodium thiosulfate, the bacteria removal results matched those observed for the control (beads without bromine). When the samples were quenched directly after collection by adding the sodium thiosulfate to the sample as soon as the desired sample volume had been collected (95 to 285 seconds depending on flow rate), between 95 and over 99 percent of the bacteria were inactivated. After 10 minutes, all of the bacteria were inactivated.
The final test involved integrating the N-halamine brominated beads into the DrainPacTM filter for a full scale test. Two sleeves containing 1400 grams of beads were laid into a DrainPacTM filter which was custom built to concentrate the flow through the beads. This system was tested using pond water with an average of 298 CFU/100 mL coliform bacteria at a flow rate of 36 GPM. The results of this test were very similar to the results of the lab scale testing. Contact time again proved to be necessary for bacteria inactivation. The filter with integrated N-halamine beads removed between 72 and 100% of bacteria with contact time between 30 seconds and 10 minutes.
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Att förebygga översvämningar med hjälp av konceptet Sponge city : En fallstudie av Hemlingby i GävleKjell, Johan, Nilsen, Filip January 2023 (has links)
Climate change is predicted to cause an increase in cloudbursts and heavy precipitation, which makes urban flooding an issue that needs to be dealt with. The term Sponge city is a theory that intends to deal with urban flooding and worsening water quality in urban areas with absorption. The study area Hemlingby is an area that has been prone to flooding before, for instance on the 17–18 of August 2021. The area is located about 3 km from the city center Gävle with Hemlingbybäcken running north through the study area. The study was performed in several parts, the first was to use the GIS tool ArcMap 10.8 and hydraulic software CAESAR-lisflood 1.8 to investigate which areas are considered sensitive. In ArcMap 10.8, a bluespot map was created to estimate how much water is needed to fill different areas of Hemlingby, and in CAESAR-lisflood 1.8, the flood inundation area was mapped based on different water flow scenarios. Subsequently, two site visits were made to the study area to photograph and validate the results from the GIS analyses. Based on the GIS analyses, an interview with the municipality of Gävle and an extensive literature analysis, measures were identified that suited both the concept and the study area. The results show what affects the drainage in Hemlingby and how it could be improved through the use of Sponge city. Hemlingbybäcken, which is easily flooded by large water flows, and the topography of the area are factors that have been identified as particularly problematic for the study area's drainage. To show how the area could be planned after the Sponge city concept, proposals for both types of measure and location have been presented, also restrictions and how similar concepts can be applied in other areas are presented. Given that the frequency and intensity of future cloud bursts are not known, there is no answer as to whether the measures presented in the study would stop the study area from being flooded in the future. Especially when data and statistics from previous rainfall were missing, the area's exact reaction to a cloud burst could not be analyzed. On the other hand, it is possible to determine from the analyzes in the method that the study area was not adapted to the type of downpour it was affected by. Therefore, measures aimed at Hemlingbybäcken become significant as the topography or soil type of the area is much more difficult to influence. In order to investigate exactly what impact the proposed measures would have on Hemlingby, further studies need to be carried out to map both the collection capacity and the impact on Hemlingbybäcken the proposal has. / Klimatförändringar förutspås i framtiden leda till en ökning av antalet skyfall och kraftig nederbörd generellt, vilket gör översvämningsproblematiken i urbana områden till ett allt större problem som måste hanteras. Konceptet Sponge city syftar på en teori vars huvuduppgift är att hantera urbana översvämningar och försämrad vattenkvalitet i städer med hjälp av absorberande ytor. Studieområdet Hemlingby i Gävle är ett område som tidigare drabbats av kostsamma översvämningar vid skyfall, bland annat 17–18 augusti 2021. Studieområdet ligger cirka 3 kilometer från Gävle stadskärna och har Hemlingbybäcken rinnandes norrut genom området. Studien utfördes i flera delar, där den första var att med hjälp av GIS-verktyget ArcMap 10.8 och den hydrologiska programvaran CAESAR-lisflood 1.8 utreda vilka områden som bedöms känsliga för översvämning. I ArcMap 10.8 skapades en bluespot-karta för att uppskatta hur mycket vatten som krävs för att fylla olika områden av Hemlingby och i CAESAR-lisflood 1.8 karterades översvämningsutbredningen utifrån olika vattenföringsscenarion. Därefter utfördes ett platsbesök i studieområdet för att fotografera och validera resultatet från GIS-analyserna. Utifrån GIS-analyserna, intervju med Gävle kommun samt omfattande litteraturanalys identifierades åtgärder som både passade konceptet och studieområdet. Resultatet visade vad som påverkar dräneringen i Hemlingby och hur den skulle kunna förbättras genom implementering av konceptet Sponge city. Hemlingbybäcken, som lätt översvämmas vid stora vattenflöden, samt områdets topografi är egenskaper som identifierats som särskilt problematiska för studieområdets dränering. För att visa hur området skulle kunna planeras efter Sponge city har förslag på både åtgärdstyp och placering presenterats, men även begränsningar och hur liknande koncept kan appliceras i andra områden presenteras. Med tanke på att frekvensen och intensiteten på framtida skyfall inte går att veta exakt, finns inget svar på om åtgärderna presenterade i studien skulle stoppa studieområdet från att översvämmas i framtiden. Eftersom data och statistik från tidigare skyfall till viss del saknats har områdets exakta reaktion på ett skyfall inte kunnat analyseras. Däremot går det att utifrån analyserna i metoden fastställa att studieområdet inte var anpassat för den typen av skyfall det drabbats av. Därför blir åtgärder riktade mot Hemlingbybäcken av mycket stor vikt, eftersom områdets topografi eller jordarter är betydligt svårare att förändra. För att undersöka exakt vilken påverkan föreslagna åtgärder skulle ha på Hemlingby behöver ytterligare studier genomföras för att kartlägga både uppsamlingsförmågan och påverkan på Hemlingbybäcken förslaget har.
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The Impact of Curing Temperature on the Hydration, Microstructure, Mechanical Properties, and Durability of Nanomodified Cementitious CompositesDan Huang (13169919) 28 July 2022 (has links)
<p>The study focused on examining the effects of using nanoadditives (nano-TiO2 and colloidal silica) on the hydration kinetics, microstructure, mechanical properties, and durability of concretes, especially those containing fly ash and slag and cured at low (4°C) temperature. </p>
<p>The results of the Vicat and isothermal calorimetery (IC) tests suggest that the addition of nano-TiO2 accelerates the hydration process of pastes. In addition, the results of the thermogravimetric analysis (TGA) indicated that the addition of nano-TiO2 increased the amount of hydration products in the pastes, with more notable increases observed in fly ash pastes. Moreover, X-ray diffraction (XRD) results revealed that the addition of nano-TiO2 reduced the mean size of calcium hydroxide (CH) crystals. </p>
<p>The interfacial transition zone (ITZ) of concretes with nano-TiO2 was found to be less cracked and less porous when compared to that of concrete without nano-TiO2. Furthermore, the energy dispersive X-ray (EDX) analyses of the outer hydration products around partially hydrated cement particles in fly ash concretes with nano-TiO2 revealed reduction in the values of Ca/Si atomic ratios when compared to the reference fly ash concrete. The image analysis results of the concrete air void system indicated slightly reduced air content, increased specific surface area (SSA), and decreased spacing factor (SF) in concretes with added nano-TiO2. </p>
<p>The addition of nano-TiO2 was also found to enhance the compressive and flexural strengths of mortars and concretes. Nano-TiO2 also improved the resistivity and formation factor values of concretes containing fly ash. Moreover, the total volume of pores, as well as the values of water absorption, were also reduced as a result of addition of nano-TiO2. This was true for all types of concretes (i.e., with or without SCMs). Finally, the use of nano-TiO2 seemed to be more beneficial with respect to improving the scaling and freeze-thaw resistance of fly ash concretes compared to cement-only and slag concretes. </p>
<p>Concretes with added nanosilica (colloidal silica) also developed higher compressive and flexural strengths when compared to reference concrete. Moreover, the total pores and permeability of concretes decreased due to the addition of nanosilica while the improvement in scaling resistance of these concretes was only slight. Furthermore, concretes with nanosilica were found to have higher percentage of finer air voids compared to reference concretes. Finally, the ITZ of concretes with nanosilica was found to have fewer defects and cracks compared to the reference concrete. </p>
<p>In summary, this dissertation presents the results of a study on the multi-scale behavior of nanomodified concretes with and without SCMs cured at both room and low temperatures. Knowledge gained from this study would be helpful in developing concretes with denser and less porous microstructure, a more refined and better-distributed air void system, improved strength, reduced permeability, and enhanced scaling and freeze-thaw resistance, especially in cases when involving the use of SCMs and exposure to low early-age temperatures.</p>
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Evaluation of the differences in characterization and classification of the rock mass quality : A comparison between pre-investigation, engineering geological forecast and tunnel mapping in the Northern Link project and the Cityline projectBenhalima, Mehdi January 2016 (has links)
In the construction of a tunnel, the characterization of the rock mass is performed in three different steps, in the pre-investigations, in the engineering geological forecast and in the tunnel mapping during construction. There has in previous work been observed that discrepancies exist between the results from these different steps, with a tendency to assign poorer rock mass quality in the tunnel mapping than in the pre-investigations and in the engineering geological forecast. One example is the work done by Kjellström [1] on the Cityline where the divergence in rock mass quality was analyzed between the different steps. If a divergence exists between the engineering geological forecast and the actual conditions observed in the tunnel mapping, it will influence both planning and budget. It is therefore important that the engineering geological forecast is as close as possible to the actual rock mass conditions in the field. The aim of this thesis was, using the case study of the Northern Link, to analyze those discrepancies in the rock mass quality estimated in the characterization and in the classification between the mapping of drill cores, the engineering geological forecast and the tunnel mapping thus complementing the work by Kjellström [1]. The aim was also identifying which parameters included in the Q-system that causes these discrepancies The analysis of the results showed that it is difficult to make the engineering geological forecast and the actual mapping match for every single meter, but that the overall correlation between them was good. The methodology used in the characterization and classification in the different phases (drill-core mapping, engineering geological forecast, tunnel mapping) may to some extent explain this divergence. The parameters Jr, Jn and Ja, included in the Q-system were the ones identified as having the largest influence on the discrepancies. In future work, it is recommended that focus is given on these parameters. A way to improve future engineering geological forecast for tunnel contracts would be to have a better follow up of the engineering geological forecast and to have standardized guidelines on how to assess clearly the value of the Q parameters in each phase (for the drill cores as well as for the actual mapping). The reduction of those differences would then lead to a better planning and budget management in future tunnel projects in Sweden.
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Pore pressures and settlements generated from two different pile drilling methods / Portryck och sättningar genererade av två olika pålborrningsmetoderAhlund, Rasmus, Ögren, Oscar January 2016 (has links)
For piling works in sensitive soil, especially in inner city projects, it is essential to be aware of the available methods and to choose the most suitable method to minimize the risk of damaging existing buildings or endanger the workers at the construction site. Down-the-hole drilling of piles is a relatively safe method and can be separated into drilling with air powered hammers and water powered hammers. This study compares water powered drilling with air powered drilling and shows that the impact on the soil generated by air powered drilling is larger than that from water powered drilling. A field study was carried out where 4 piles were drilled, two with air powered DTH drilling and two with water powered DTH drilling. The drilling was carried out in clay resting on an approximately 4 m layer of silt and friction soil. The total soil depth was about 12- 15 m. To analyze the soil influence, settlements were measured at ground level and in depth and pore pressure was measured in the middle of the clay layer. This study distinguished two major problems when drilling through this type of soil. The first is the risk of over-drilling in the friction layer. The second problem is the risk of increasing the pore pressure in the clay. Both these problems were experienced when using air powered drilling but for the water powered case only a small pore pressure increase and no over-drilling was observed. In conclusion, drilling with water has less influence on the soil in the sense that it gives a smaller effect on the pore water pressure and causes smaller settlements. / För pålningsarbeten i känsliga jordar och speciellt i innerstadsprojekt är det viktigt att vara medveten om befintliga metoder och välja den mest gynnsamma av dessa för att på så sätt minimera de risker som är sammankopplade med arbetet. Sänkhammarborrning är en relativt säker påldrivningsmetod och kan delas upp i luftdriven borrning och vattendriven borrning. Det här arbetet jämför dessa två metoder och visar att formationspåverkan vid luftdriven borrning är större än den vid vattendriven borrning. Arbetet baseras på en fältstudie där totalt 4 pålar borrades, två med luftdriven borrning och två med vattendriven borrning. Borrningen genomfördes i en formation med lera ovanpå silt och ren friktionsjord och jorddjupet på platsen varierade mellan 12-15 meter. För att undersöka formationspåverkan mättes sättningar på djupet och på markytan och portryck mättes mitt i lerlagret. Arbetet kunde urskilja två huvudsakliga problem vid borrning i den här typen av formation. Det första är risken för överborrning i friktionslager och det andra är risken för portrycksökning i tätare lerlager. Båda dessa fenomen observerades när luftborrning utfördes men inget av dem kunde urskiljas då vattenborrning utfördes. Sammanfattningsvis kan sägas att vattendriven borrning påverkar jorden mindre i den mening att den ger upphov till mindre portrycksökning och orsakar mindre korttidssättningar.
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Optimization in Design of End-Bearing Concrete and Steel Piles with Regard to Climate Impact : Climate Conscious Material Choices in Early Project Planning / Klimateffektiviserad dimensionering av spetsburna stål- och betongpålar : Klimatsmarta materialval i tidig projekteringAdnan, Simat, Ton, Jann January 2021 (has links)
Environmental sustainability is becoming more popular in the building industry. Sustainable thinking needs to be present during the whole construction process, from the idea phase to the final stages. The aim of this master thesis is to investigate how end-bearing concrete and steel pipes as well as composite concrete-filled steel tube piles can be designed with greater consideration to climate impact. The purpose of this study is primarily to encourage awareness during the material choice phase in early stages of project planning. A Matlab code was programmed to perform a parametric study and analyze different parameters effect on pile bearing capacity. The structural bearing capacity of a number of different piles with various prerequisites were compiled in tables. The climate impact of the piles was expressed as global warming potential (GWP). In order to compare different pile types a functional unit was created as the ratio of the piles' bearing capacity and the corresponding climate impact. The ratio was calculated for all the piles and resulted in a number of figures with bearing capacity as a function of climate impact. These figures are supposed to be used as a basis to choose which pile type is most useful in a given situation. The usability of the results was verified with a calculation example. In the example, the figures were used to chose one pile out of several options as the most climate-efficient with the highest usage ratio. Finally, a number of general conclusions could be drawn regarding pile types. When the corrosion is small (<2 mm), it can be ascertained that steel pipes are to prefer over composite pipes. With larger corrosion (>2 mm), it can be ascertained that composite piles are preferable, specifically in cases were the soil is looser. However, in firmer soil, with undrained shear strength between 10-25 kPa, composite concrete-filled steel pipes are the better option. The results show that the contribution of the concrete to the bearing capacity of the composity files is minimal compared to the contribution of the decreased inner corrosion. This implies that it is more important to have the pipes filled with to prevent inner corrosion, rather than use a strong material that contributes to the bearing capacity. With that said, composite piles are not sustainable and different filling materials can be examined to further investigate whether there is another material with smaller climate impact that makes for piles with larger ratio of bearing capacity to climate impact. The main conclusion of the master thesis is that there needs to be a standardised approach to calculating climate impact from foundation construction and it should be included in a building's life cycle analysis (LCA). / Miljövänlighet och hållbarhet är begrepp som förekommer allt oftare i byggbranschen.Hållbarhetstänket behöver finnas med under hela byggprocessen, från idéfas till slutskede. Syftet med det här examensarbetet är att undersöka hur dimensionering av spetsburna betong- och stålrörspålar samt samverkanspålar kan utföras med större hänsyn till klimatpåverkan. Målet är framför allt att med hjälp av enklare klimatkalkyler främja klimatmedvetna materialval i tidig projektering. En parameterstudie som undersökte olika parametrars påverkan på pålens bärförmåga och klimatpåverkan utfördes i Matlab. Den strukturella bärförmågan hos ett antal olika pålar med olika förutsättningar som indata sammanställdes. Pålarnas klimatpåverkan uttrycktes i deras globala uppvärmningpotential (GWP) och för att kunna jämföra olika pålar med varandra skapades en gemensam funktionell enhet. Kvoten mellan pålarnas bärförmåga och motsvarande klimatpåverkan utgjorde den funktionella enheten. Kvoten beräknades för samtliga undersökta pålar och resulterade i ett antal figurer med bärförmåga som funktion av klimatpåverkan. Dessa figurer ska fungera som underlag vid bestämning av påltyp och användbarheten verifierades med ett beräkningsexempel. Med hjälp av de framtagna graferna gick det i beräkningsexemplet att välja ut pålen som var mest effektiv med hänsyn till klimatpåverkan och utnyttjandegrad av flera möjliga alternativ. Ett antal generella slutsatser gällande påltyp kunde dras. Vid små rostmåner (<2 mm) kan det konstateras att stålrörspålar är mer fördelaktiga än samverkanspålar. För resterande rostmåner (>2 mm) är samverkanspålar lämpligare i de fall där jorden är lösare. I fastare jordar med odränerad skjuvhållfasthet mellan 10-25 kPa är betongfyllda stålrörspålar utan samverkan ett bättre alternativ. Resultaten visar att det som ger störst effekt inte är betongens bidrag till bärförmågan utan det är minskningen av den inre rostmånen som har störst påverkan. Det innebär att det är viktigare att pålen är fylld än att den är fylld med något starkt som kan bidra med bärförmåga. Alltså är det inte hållbart att använda samverkanspålar och man kan vidare undersöka om det räcker att fylla med något klimatvänligare material som exempelvis cementbruk med lägre cementinnehåll och cementkvalité. Arbetets viktigaste slutsats är att det behövs en standardiserad beräkningsmetod för klimatpåverkan från grundläggning och att det bör ingå i byggnaders livscykelanalyser (LCA) eller klimatdeklarationer.
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Development of grout for deep shaft / Utveckling av injekteringsbruk till djupt schaktLindberg, Karl, von Krusenstierna, Adam January 2021 (has links)
In tunnel engineering one of the most important factors are the groundwater flow. To solve this problem a method called grouting is commonly used. In this study grout mixes are developed based on specific requirements for a deep shaft located next to a body of water. These circumstances require a grout with extraordinary penetrability and durability. During the excavation of a shaft, different groundwater pressures and fracture structures is going to be present. This creates conditions where different types of grouts are necessary. In order to develop grout, there are several factors that needs to be taken into consideration. Some of these are the cement properties, additive properties and amounts, water cement ratio, mixing regime, external physical impact etc. In this study several experiments were used to determine the properties of the grout mixes in order to fulfil the requirements needed for certain rock conditions. Three different cements and several additives have been used in different combinations in order to find the right mix. The first step of the experimental process is to do screening tests. The screening tests consists of penetrability, flow and density tests. After a grout passes these tests, several other tests are performed to ensure the right properties. In the beginning of the experiments, problems occurred with one of the cements which led us to suspect the quality of the cement. In order to ensure that the sources of error from lab equipment, different production dates, conditions of cements and additives are excluded several tests were performed. The test results of the cement did not improve regardless of the troubleshooting.When another cement type was tested the results immediately improved and passed the screening test. The test results from the new cements and additives led to further testing and development of two approved grout mixes. When another cement type was tested the results immediately improved and passed the screening test. The test results from the new cements and additives led to further testing and development of two approved grout mixes. / Vid tunnelbyggande är en av de största utmaningarna tätning av berget för att undvika vatteninträngning. Detta är viktigt av flera anledningar. Grundvatteninträngning kan resultera i en lokal grundvattensänkning som kan medföra förödande konsekvenser. Det kan leda till sättningar som i sin tur leder till skador på byggnader och även den befintliga växtligheten kan förstöras av en allt för stor grundvattensänkning. Det finns flera tekniska åtgärder till detta problem och ett exempel på detta är tätning med injekteringsbruk.Syftet med denna studie var att utveckla tre olika injekteringsbruk som har de egenskaper som krävs i schaktet vid Stadsgårdskajen. Egenskaperna som hade krav på att uppfyllas var penetrationsförmåga, sättningstid, sträckgräns, skjuvhållfasthet, rinntest, vattenseparation och densitet.Studien är i huvudsak byggd på det egna laborerade arbetet men har kompletterats med vetenskapliga rapporter där den viktigaste källan var Betonghandboken Material. För att få kunskap om de specifika materialen som användes i studien fanns tekniska datablad för respektive produkt.Resultaten visar hur olika cementtyper reagerar med olika kombinationer av tillsatser och vattencementtal. Tester genomfördes på tre olika typer av portlandcement varav två av dessa var sulfatresistenta. Tillsatserna som användes i studien var superplasticerare, accelerator, retarder och viskositetstabiliserare. Resultaten är uppdelade i VCT (vattencementtal) för respektive cementtyp.Några slutsatser av studien är att RHEOCEM 650 SR inte fungerade som förväntat. Detta sannolikt på grund av dålig cementkvalité. MasterRoc MP 650 och Injektering 30 gav betydligt bättre resultat och det är från Injektering 30 som de båda godkända mixarna utvecklades från. Ifall fortsatta studier hade genomförts hade en godkänd mix 1 utvecklats. Det hade även varit intressant att se hur de olika godkända mixarna fungerade i praktiken.
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Slope Stability Analysis Using the Kinematic Element MethodKader, Adnan January 2019 (has links)
Thesis regarding the application of the Kinematic Element Method to slope stability analysis in geotechnical engineering. / In this thesis, the effectiveness of the Kinematic Element Method (KEM), developed by Dr. Gussmann at the University of Stuttgart, was evaluated by comparing the solutions with the Limit Equilibrium Method (LEM), specifically the Morgenstern-Price method. The KEM was evaluated using a variety of problems, ranging from homogeneous slopes to retaining walls. The KEM was shown to predict similar potential failure mechanisms and values for the factor of safety (FS) as the Morgenstern-Price method. The FS were generally within the ±6% which is the range of variance for rigorous limit equilibrium methods. A simplified version of KEM (KEMv) was developed based on limit equilibrium formulations. In KEMv, an alternate iterative scheme to determine the FS is proposed, in which boundaries between elements are vertical. The KEMv provided similar values for the factor of safety and interelement forces as Gussmann’s KEM for vertical interelement boundaries given similar element locations. The KEM was assumed by Gussmann to be an upper bound solution. However, given the similarities in the solutions between KEM and KEMv, it may be a limit equilibrium method. The interelement forces from the KEM and KEMv were found to be sensitive to the location of the elements. Elements in the upper part of the slope often had small normal forces relative to shear forces, possibly being negative as well. Sensitivity analysis regarding the number of elements showed that a 5-element solution predicts the appropriate failure mechanism and provides a reasonably accurate FS. In a parametric study, slope geometry and soil properties were varied and comparisons were made between KEM and the Morgenstern-Price method. The KEMv displayed similar trends in factor of safety as the Morgenstern-Price method but predicted slightly larger values. The change in KEM critical slip surfaces with soil properties was consistent with trends predicted by Janbu’s dimensionless parameter. / Thesis / Master of Applied Science (MASc) / The stability of slopes is a challenging subject in geotechnical engineering. Geotechnical engineers are often interested in the factor of safety (FS), which is a quantitative measure of the stability of a slope. In this thesis, the effectiveness of the Kinematic Element Method (KEM) is evaluated by comparing its solutions to the Limit Equilibrium Method (LEM). The KEM was shown to predict similar potential failure mechanisms and values for the factor of safety. A simplified version of the KEM (KEMv) was developed based on LEM formulations. In KEMv, an alternate iterative scheme to determine the FS is proposed, in which the boundaries between elements are vertical. The KEMv provided similar values for the factor of safety and element forces as Gussmann’s KEM for vertical interelement boundaries. In a parametric study, KEM displayed similar trends in the change in FS and critical slip surface as the LEM.
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Utvärdering av Inspect a Surface : En applikation i fältmjukvaran Leica CaptivateGräns, Sandra, Östblom, Simon January 2018 (has links)
Inom geodetisk mätning har den tekniska utvecklingen inom terrester laserskanning (TLS) gått fort framåt sedan millennieskiftet. Tack vare dess framgång har TLS etablerat sig väl på marknaden som skanningsmetod och användningsområdena har därefter utvidgats. Leica Geosystems AB är ett internationellt mätningsteniskt företag, vilka har lanserat sin nya multistation Leica Nova MS60 med fältmjukvaran Leica Captivate. Till mjukvaran hör också applikationen Inspect a Surface, som möjliggör mätningsingenjör att kunna utvärdera erhållna skanningsdata ute i fält. Applikationen är ämnad att användas vid kontroll av ett skannat objekt genom att testa punktmolnet mot en definierad referens. Företaget har intresse av att en studie av denna karaktär utförs på deras produkter då det inte gjorts tidigare. Undersökningens primära syfte är att utröna i vilken grad fältmjukvaran Leica Captivate med applikationen Inspect a Surface i en Leica Nova MS60 står sig i jämförelse med traditionell efterbearbetning i extern mjukvara. Skanningar utfördes både i utom- och inomhusmiljö mot objekt som vanligen går att finna på byggarbetsplatser, såsom fasad, vägg, golv och cylindriska objekt med varierande radie och materialsegment. De horisontella och vertikala ytorna testades mot inmätta referenspunkter respektive interpolerade referenspunkter. Skanningsdata för cylindrar erhölls av MS60 respektive Leica Scan Station C10 för att visuellt undersöka fenomenet ”mixed pixels”. En cylinderinpassning i Leica Cyclone gjordes mot respektive segment för att se dess radie-avvikelse från referens och jämföra resultaten för respektive instrument. Även signifikanstest utfördes. Resultatet av undersökningen visar att utvärdering av ytor ger likvärdiga resultat i samtliga mjukvaror. Felkällan mixed pixels influerade i varierande grad för punktmolnen erhållet från MS60 och C10. Felkällan var som mest förekommande på materialet aluminium och tapetsegmentet som var närmast golvet. Cylinderpassning mot punktmoln från respektive instrument avvek på millimeternivå från varandra och referensen. Enstaka större avvikelser förekom bland annat på aluminiumsegmentet. Den slutsats som drogs var att applikationen är tillfredsställande att användas för efterbearbetning direkt ute i fält. Skanning av cylindrarna ledde till slutsatsen att skanningsdata från MS60 drabbas av felkällan mixed pixel i större grad än C10 bara om en yta är nära bakom cylindern. Samtidigt drabbades punktmolnet från C10 av mixed pixels om det var fritt bakom cylindrarna. Att använda sig av MS60 för skanning av cylindriska objekt visade sig vara tillfredsställande. / The technical development of terrestrial laser scanning has quickly proceeded in geodetic measurement since the millennium shift. Its success has made TLS well established on the market as a method of scanning and its field of applications has expanded. Leica Geosystems is an international company in the field of surveying and measurement instruments. They have developed a new multistation, Leica Nova MS60 with the field software Leica Captivate. In addition to the software the application Inspect a Surface allows surveyors to evaluate obtained point clouds in the field. The application serves the purpose of controlling an object by comparing a pointcloud with a defined reference. The company is interested of such a study to be made on their products, as it has not been conducted before. The main purpose of the study is to determine to what extent the field software Leica Captivate with Inspect a Surface in a Leica Nova MS60 manages with traditional post processing in external software. Scanning in indoor and outdoor environment was performed on objects common on construction sites, such asfacade, wall, floor, and cylindrical objects with varying radius and material segments. The horizontal and vertical surfaces were tested against measured reference points and interpolated reference points. Scanning data for cylinders was obtained by MS60 and Leica Scan Station C10 for a visual control of the phenomenon “mixed pixels”. In Leica Cyclone, a cylinder was fitted on each segment in order to determine radius deviation from reference and compare the results from each instrument. A hypothesis test was also conducted. The study shows that surfaces had equivalent results in all softwares. The error source mixed pixels influenced pointclouds from MS60 and C10 in varying degree. The error source was occurred most frequenlty on the aluminum and wallpaper segment which were close to the floor. Cylinder fitting on point cloud from, MS60 and C10 deviates millimeters from each other and the reference, apart from a few bigger deviations, the aluminum-segment for instance. The conclusion is that the application is satisfactory for post processing in the field. Scanning of cylinders leads to the conclusion thad mixed pixels occurs for MS60 more than C10 only if a surface is behind the cylinder. On the contrary, mixed pixels occur on C10 if there is free space behind the cylinder. Using MS60 for scanning of cylindrical object turns out to be satisfactory.
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