This thesis deals with numerical simulation of earth pressure against tubular bridges in the software Plaxis. Plaxis is a FEM (Finite Element Method) software based on numerical calculations for which approximate solutions are developed through an iterative process. The program is specifically designed for soil and rock mechanical tests, such as voltage and deformation calculations in soil.The Royal Institute of Technology conducted in 2005, field tests on tubular bridges of corrugated steel, which was part of Ersa Bayoglu Fleners PhD (Bayoglu Flener, 2009). She studied how two different tubular bridges deformed during installation and filling. Tests and measurements were made during filling. The location of the construction and measurements of tubular bridges was a field in Järpås, Lidköping. The company responsible for the production of the tubular bridges was ViaCon AB.This thesis is based on these measurements. Inspiration has also been the newspaper article, "Earth Pressure on an Integral Bridge Abutment: A Numerical Case Study" by Muir, and Nash (Wood & Nash, 2000) which describes how compaction can be simulated in the FEM program. With the above as a starting point, the numerical simulations were carried out.The voltage increase that occurs when the soil is packed has been simulated in the constitutive models Mohr Coulomb, Hardening Soil model in Plaxis from the article by Wood & Nash (2000).  The article by Muir Wood and Nash & Nash, 2000) described a recipe procedure, where compaction was simulated by imposing an external weight on the fill which then seemed the same. In the next calculation step, the earth was removed, a new fill was imposed and the calculation was carried out. In the subsequent calculation step, the load was re-imposed. Calculation steps were repeated until the desired fill level was achieved, i.e. The tubular bridge was completely covered. The tubular bridge's deformation during filling was studied. The early filling stages deformed the tubular bridge's head upwards. Deformation proceeded until filling reached the crown. Then there was a downward deflection. The results of shell deformation were then compared against Fleners studies as well as previous, similar numerical calculations performed by Segovia (Segovia, 2006).The results obtained during the numerical analysis were greatly underestimated. The shell deformed to the same extent as in the real field measurements. The deformation patterns corresponded to each other during the filling phases, but when the fill had reached the top of the head, the calculations began to diverge from the deformations in the numerical analysis. This is in contrast to field measurements where the deformation continued. In a comparison between Segovia and this study the results are not so very different, even though the deformations in this study are slightly smaller than those in Segovia's study. The difference in results may be due to the tubular bridges construction in Plaxis. The tubular bridge in this study was made based on sketches from ViaCon AB using the tunnel feature in Plaxis. One reason for the deformations are kept may be due to Plaxis' overestimate of the earth's rigidity and that the response from the simulated gasket fails.Finally, we studied the constitutive models' input parameters to see which parameter had the greatest impact on the tubular bridge's deformation at and around filling. The results from the parametric study were difficult to interpret. Although input data was varied, there was not any significant variation in results regarding the shell deformation. No parameter stuck out from the crowd. This shows how important it is to select an input that reflects what is to be simulated.

A building with high levels of radon gas in the indoor air has a negative effect on the users of the building. Radon in buildings is one of the most common cause to lung cancer in Sweden today, which is why the Boverkets byggregler have set a limit value of 200 Bq/m3 for indoor air in new buildings. The limit value is twice as high as the limit value set by WHO, due to the high uranium levels in Sweden. The soil conditions in Sweden vary, which leads to the problem with the concentration of radon in the soil being different in different geographical locations in Sweden. The thesis has examined routines regarding radon in the soil at the design stage at Skanska in Helsingborg to highlight the risks of the municipality designating the area as a low-risk area. The methods used in this thesis consists of a survey, interviews and examination of documents and geodata. The survey and interviews were conducted with employees at Skanska in both Helsingborg and Uppsala, in order to make a comparison between two areas where the radon problem differ. The results show that there are gaps in knowledge about radon among the employees in Helsingborg, due to lack of experience. If the municipality does not set requirements regarding radon in the inspection plan, Skanska will not do so either. The results also show from measurements that there are areas in Helsingborg that should be considered a high-risk area for radon. One conclusion for the thesis is that regular internal education regarding radon can be beneficial in an area that is considered a low-risk area, as there is a lack of practical experience. Another conclusion is that it is misleading to generalize an area as a low-risk area, as measured values from radon examination in soils show local differences. A recommendation is therefore to always perform a radon examination before a new building is constructed.

No description available.

Att kunna utvärdera dynamiska parametrar i finkornig jord har blivit allt mer aktuellt i Sverige, inte minst på grund av de nya höghastighetsbanorna som ska byggas inom snar framtid. Tågens höga hastigheter kommer skapa dynamiska vågor som breder ut sig i den underliggande jorden. Om vågorna inte är snabbare än tåget själv, kan en dynamisk amplifikation ske vilket kan skapa obehag för passagerarna och stabilitetsproblem i jorden. Risken för dessa problem finns i lösa och finkorniga jordar där våghastigheterna är relativt låga.Syftet med detta examensarbete är att studera vilken inverkan konsolideringen har på skjuvvågshastigheten i finkornig jord samt att undersöka om befintligt empiriskt samband från Trafikverkets tekniska kravdokument (TK Geo) ger tillförlitliga värden på skjuvvågshastigheten. För att besvara detta har Seismic Cone Penetration Test (SCPT) utförts för att mäta skjuvvågshastigheten i finkornig jord under och utanför provbankar. Materialparametrarna som har använts i det empiriska sambandet har erhållits från rutinundersökningar, CRS och CPT-sonderingar.Undersökningen har utförts på SGI;s två provfält med olika finkorniga jordar, det ena i Skå-Edeby och det andra i Lampen. Provfältet i Skå-Edeby har stått i drygt 60 år och nya kolvprover och CPT-sonderingar utfördes för att erhålla aktuella materialparametrar. I Lampen har provfältet stått i knappt tio år men där har inga nya jordprover tagits utan resultat från tidigare utförda undersökningar har legat till grund för de empiriska beräkningarna.Resultatet från undersökningen i Skå-Edeby påvisar tydligt att konsolidering av finkornig jord ökar skjuvvågshastigheten i jorden. I Lampen blev resultatet inte lika tydligt men visar ändå generellt sett högre värden hos skjuvvågshastigheten i den konsoliderade jorden jämfört med jungfrulig jord.Skjuvvågshastigheterna som beräknats med hjälp av det empiriska sambandet verkar ge tillförlitliga resultat där de i Skå-Edeby följer en likartad trend som de uppmätta skjuvvågshastigheterna. För Lampen är däremot trenden inte lika tydlig där de empiriska beräkningarna mestadels gav högre skjuvvågshastigheter än de uppmätta hastigheterna vid de olika nivåerna i jordprofilen. Den bästa överensstämmelsen mellan uppmätt skjuvvågshastighet och empiriskt uppskattad skjuvvågshastighet erhölls dock för den obelastade, jungfruliga jorden vid båda undersökningsplatserna. / The ability to evaluate dynamic parameters in fine grain soil has become more relevant in Sweden, not least because of the new high-speed railways that are planned to be built in the near future. The high speed of the trains will create dynamic waves that will spread into underlying soil. If the velocity of these waves is slower than the train itself, it could create a dynamic amplification which can cause discomfort for passengers and stability problems in the soil. This is a risk in loose and fine grain soils where the wave velocity is relatively low.This work aims to study what impact consolidations have on the shear wave velocity in fine grain soil and also to evaluate if existing empirical relationship from the Swedish transport administration gives reliable results regarding the shear wave velocity. In order to answer this, the method SCPT (Seismic Cone Penetration Test) have been used to measure the shear wave velocity in fine grain soil beneath and next to an embankment. The material parameters that´s been used in the empirical relationship has been obtained from routine investigation, CRS and CPT-probes.Field investigations has been performed at SGI;s two test fields with different kind of fine grain soil, one in Skå-Edeby and the other one in Lampen. The test field in Skå-Edeby has been standing for 60 years and new piston samples and CPT-probes has been performed to obtain current material parameters. In Lampen, the test field has been standing for almost ten years and no new soil samples have been taken. Instead, results from previous performed soil investigations has been used in the empirical calculations.Results from the study in Skå-Edeby clearly show that the consolidation of fine grain soil increases the shear wave velocity in the soil. In Lampen, the results were not as clear but still show generally higher values of the shear wave velocity in the consolidated soil compared to virgin soil.The shear wave velocities calculated using the empirical relation appear to produce reliable results where, in Skå-Edeby, they follow a similar trend as the measured shear wave velocities. For Lampen, however, the trend is not as clear where most of the empirical calculations gave higher velocities than the measured ones at most levels in the soil profile. For both Skå-Edeby and Lampen, the smallest difference between measured and empirical shear wave velocities were obtained in the unloaded, virgin soil.

Cemented paste backfill (CPB) is a novel technology developed in the past few decades to better manage mining wastes (such as tailings) in environmentally friendly way. It has received prominent interest in the mining industry around the world. In this technology, up to 60% of the total amount of tailings is reused and converted into cemented construction material that can be used for secondary support in underground mine openings (stopes) and to maximize the recovery of ore from pillars. CPB is an engineered mixture of tailings, water, and hydraulic binder (such as cement), that is mixed in the paste plant and delivered into the mine stopes either by gravity or pumping. During and after placing it into the mine stopes, the performance of CPB mainly depends on the role of the hydraulic binder, which increases the mechanical strength of the mixture through the process of cement hydration. Similar to other fine-grained soils undergoing cementations, CPB’s behavior is affected by several conditions or factors, such as cement hydration progress (curing time), chemistry of pore water, mixing and curing temperature, and filling strategy. Also, it has been found that fresh CPB placed in the mine stopes can be susceptible to many geotechnical issues, such as liquefaction under ground shaking conditions. Liquefaction-induced failure of CPB structure may cause injuries and fatalities, as well as significant environmental and economic damages. Many researches studied the effect of the aforementioned conditions on the static mechanical behavior of CPB. Other researches have evaluated the liquefaction behavior of natural soils and tailings (without cement) during cyclic loadings using shaking table test technique. Only few studies investigated the CPB liquefaction during dynamic loading events using the triaxial tests. Yet, there are currently no studies that addressed the liquefaction behavior of CPB under the previous conditions by using the shaking table technique. In this Ph.D. study, a series of shaking table tests were conducted on fresh CPB samples (75 cm × 75 cm ×70 cm), which were mixed and poured into a flexible laminar shear box (that was designed and build for the purpose of this research). Some of these shaking table tests were performed at different maturity ages of 2.5 hrs, 4.0 hrs, and 10.0 hrs, to investigate the effect of cement hydration progress on the liquefaction potential of CPB. Another set of tests were conducted to assess the effect of the chemistry (sulphate content) of the pore-water on the cyclic response of fresh CPB by exposing cyclic loads on couple of CPB models that contain different concertation of sulphate ions of 0.0 ppm and 5000 ppm. Moreover, as part of this study, series of shaking table test was conducted on CPB samples that were prepared and cured at different temperatures of 20oC and 35oC, to evaluate the effect of temperature of the cyclic behavior of CPB. Furthermore, the effect of filling strategy on the cyclic behavior of fresh CPB was assessed by conducting set of shaking tables tests on CPB models that were prepared at different filling strategies of continuous filling, and sequential or discontinuous (layered) filling. The results obtained show that CPB has different cyclic behavior and performance under these different conditions. It is observed that the progress of cement hydration (longer curing time) enhances the liquefaction resistance of CPB, while the presence of sulphate ions diminishes it. It is also found that CPB mixed and cured in low temperature is more prone to liquefaction than those prepared at higher temperatures. Moreover, the obtained results show that adopting the discontinuous (layered) filling strategy will improve the liquefaction resistance of CPB. The finding presented in this thesis will contribute to efficient, cost effective and safer design of CPB structures in the mine areas, and will help in minimizing the risks of liquefaction-induced failure of CPB structures.

Genom samarbete med konsultföretaget Tyréns har detta examensarbetet undersökt hur en säkrare prognos kan erhållas för bergprojektering. Till underlag undersöktes ett aktuellt projekt i Jakobshyttan, med fokus på släntstabilisering. Med avseende att identifiera de osäkerheter sompåverkar bestämmandet av bergets parametrar har parametrarnas inverkan på stabiliteten och dess kostnadseffekt på stabilisering studerats. Framtagandet av de relevanta parametrarna identifierades genom litteraturstudie, Tyréns bergtekniska prognos, relevanta handlingar för området och studiebesök på arbetsplats. Vidare utfördes en känslighetsanalys på de parametrar som var relevanta för stabilitets problematiken, för att utvärdera de kritiska gränserna för respektive parameter. För arbetet användes Barton och Bandis brottvillkor baserat på den bergtekniska informationen som fanns tillgänglig. Slutligen utfördes en kostnadsberäkning för deparametrar som identifierats med eventuella osäkerheter, för att ge perspektiv på effekten av osäkerhet. Resultatet visade att parametrarna JRC och residualfriktionsvinkel hade kraftig inverkan på stabiliteten. Parametrarnas värde bestämdes enligt föreslagen metodik från Trafikverkets handbok för bergprojektering och uppskattats genom tabeller baserade på empiriska fall. Sammanfattningsvis har den rekommenderade metodiken från Trafikverket ansetts som bristfällig och ger utrymme för felbedömningar i projekteringsskedet. / Through collaboration with the consulting company Tyréns, this thesis has investigated how a more reliable forecast can be obtained for rock design. As a basis, a current project in Jakobshyttan was investigated, focusing on slope stabilization. With regard to identifying the uncertainties that affect the determination of the rock parameters, the parameters impact on thestability and its cost effect on stabilization have been studied. The relevant parameters were identified through literature study, Tyréns forecast of rock technology, relevant documents for thearea and study visits to the workplace. Furthermore, a sensitivity analysis was performed on the parameters that were relevant to the stability problem, in order to evaluate the critical limits foreach parameter. The thesis used Barton and Bandis failure criteria based on the rock technical information that was available in the project. At last a cost calculation was performed to provide perspective on the effects of each of the parameters identified as being uncertain. The results showed that the parameters JRC and residual friction angle had a big impact on the stability. The value of the parameters was determined according to the proposed methodology from the customer, the Swedish Transport Administration, and was estimated through tables based on empirical cases. In summary, the recommended methodology from the Swedish Transport Administration has been considered deficient and leaves room for incorrect assessments in the design phase.

<p>Shallow foundations are used to support small-to-medium size structures, and their capacity derives from the strength of strong, near-surface soils. The design of shallow foundations is done by proportioning the plan dimensions of the foundation element by considering three factors: (1) the structural stability of the foundation, (2)  the allowable bearing pressure of the soil supporting the foundation to prevent ultimate bearing capacity failure, and (3) the tolerable total and differential settlements to meet serviceability requirements under normal working loads. Different theories have been developed to estimate the bearing capacity of a foundation, mostly relying on the Terzaghi (1943) form of the bearing capacity equation with the superposition of three terms. The partly theoretical and empirical methods of bearing capacity predictions rely on an assumed failure mechanism within the soil. In addition, the soil itself is considered to be a perfectly plastic material and its strength is accounted for through non-dimensional bearing capacity factors. However, the boundary-value problem of footing penetration, in reality, is quite complex and the use of the traditional bearing capacity, with use of the principle of superposition, leads to somewhat conservative results. The challenges involved in a footing penetration problem emanate not only from the difficulties in estimating soil strength parameters but also because the footing penetration problem involves large deformations and strains, which localize to form shear bands that propagate in the soil domain until the "collapse" of the sand-footing system.</p> <p>The overarching aim of this research is the study of the response of shallow foundations on clean silica sands by investigating the measured bearing capacities and getting insights into the failure mechanisms that develop as a result of the soil displacements below the base of the foundation element. This was experimentally achieved using a combination of physical modelling (by performing a series of model footing 1g load tests inside a novel half-circular calibration chamber) and image analysis (using digital image correlation technique). The load-settlement response of the model footings is investigated by performing displacement-controlled load tests on model strip and square footings placed either on the surface or embedded in the sand samples of varying relative densities prepared inside the calibration chamber using the method of air-pluviation. A series of high-resolution images collected during model footing loading were analyzed using the digital image correlation (DIC) technique to obtain the displacement and strain fields in the sand domain. Two fully characterized silica sands, Ohio Gold Frac (OGF) and Ottawa 20-30 (OTC) are used in the research. Different testing variables that were considered in the experimental setup are: (1) sand particle morphology, (2) sand sample's relative density, (3) sand layer thickness, and (4) footing shape, size, and embedment depth. A detailed test matrix was formulated to isolate these variables and study the effects of each on both the bearing capacity and the associated failure mechanism. Accordingly, this article-based dissertation is organized to describe the results of three studies.</p> <p>In the first study, the effects of relative density and particle morphology on the bearing capacity and failure mechanism of a model strip footing were investigated. This was done by using two silica sands: OGF sand and OTC sand, both the sands have comparable mineralogy, gradation, and particle sphericity; however, they have markedly different values of particle roundness. Samples of both sands were prepared at relative densities of 90%, 65%, and 30%. The evolution of the footing's collapse mechanism was considered by selecting relevant points on the load-settlement curves. A novel methodology was adapted to record the thickness of the shear band that developed in the sand domain. In the second study, the effects of the presence of a stiff layer below the strip footing were investigated. This was achieved by load testing the model strip footing on OTC sand layer of limited thickness. To simulate the sand-bedrock system, a half-circular steel plate supported by a stack of hollow concrete blocks was used. Load tests on model strip footing were performed on OTC sand samples without the presence of a stiff base and on the sand samples underlain by a stiff base located at depths equal to 0.5B and 1B below the base of the footing. The effect of the presence of the stiff base on the limit unit bearing capacity of the footing and stiffness of the sand-footing system were investigated. In addition, the contours of the cumulative maximum shear strains, horizontal displacements, and vertical displacements that develop in the sand layer are presented for both cases of with and without the presence of the stiff base. In the third study, the effects of footing geometry and embedment on the bearing capacity and failure mechanism were investigated. Load tests were performed on surface and embedded model strip and square footings on dense, medium dense, and loose OTC sand samples. The effects of choice of flow rule (associative versus non-associative) on the bearing capacity calculation and the increase in bearing capacity due to footing embedment (bearing capacity ratio) were determined. In addition, a framework is proposed to experimentally determine the shape and depth factors using strip and square footings of equal widths considering the flow rule non-associativity, conditions of low confinement, and different loading paths.</p> <p>The results of the experimental program presented in this research on bearing capacity, displacement fields, strain fields, and failure mechanisms for different footing sizes and shapes under different testing conditions show that that the footing's collapse mechanism depends on the relative density of the sand sample, sand particle morphology, and the footing geometry. Significant differences in the bearing capacity of model footings due to sand particle morphology and sand sample density were observed. The shear band thickness is also shown to be dependent on the shape of the sand particles. It was also observed that the scale effects in model footing tests are closely related to sand dilatancy. For a sand layer of finite thickness underlain by a stiff base it is shown that the critical depth of the stiff base is greater for stiffness calculation than that for the bearing capacity calculation. DIC analysis results provided valuable insights to the footing penetration problem and corroborated the theoretical knowledge about the failure modes in sandy soils. It is shown that the failure mechanism extend deeper and wider for sands with angular particles as compared to the sand with rounded particles. DIC analysis also revealed that as the distance between the footing base and stiff layer reduces, the shear bands are more readily formed but their lateral extents are reduced considerably. The high-quality experimental data provided in this dissertation is aimed to be useful to researchers working on the validation of numerical simulations of footing penetration in sands.</p>

The mining industry has over the last few decades seen a drastic increase in the usage of laser scanning technologies as a way of creating 3D maps of the mines being exploited. Underground mapping in places such as mines has become more prevalent as the technology has progressed and made it easier to generate highly detailed point clouds faster. A newer and faster method of generating point clouds is using a simultaneous localization and mapping (SLAM) based mobile laser scanner (MLS). With the help of complex algorithms, it enables instant point cloud registration and allows for continuous mapping of the surrounding environment while tracking the device location without needing a connection to GPS. As the accuracy and speed of SLAM based MLS continues to improve, its use is becoming far more widespread within the mining industry. Although studies have been conducted previously investigating the differences in quality between SLAM based MLS and terrestrial laser scanners (TLS), there is still a need for further studies conducted in mining environments. This case study aims to investigate the quality differences between two point clouds generated using an Emesent Hovermap HF1, which is a SLAM based MLS, and a Faro Laser Scanner Focus 3D X 330 TLS. Parameters like root mean square (RMS) were investigated. Volume calculations were carried out for both point clouds and compared to each other as well the calculated volume of a theoretical model. To conduct this study data from LKAB’s Kiruna mine was collected and provided by Blå Projekt, Process &amp; GIS AB. The result of this study concludes that the Faro TLS is superior in terms of point cloud quality, with five times better RMS values and higher point density than the Hovermap MLS. It also shows that both scanners allowed for accurate volume calculations with only roughly 1% difference in the estimated volumes. The TLS method yielded a much more readable point cloud with clearer visual details than the SLAM based MLS method. This may however be a result of SLAM drift since no loop closure was performed when collecting the MLS data which otherwise could’ve minimized the errors. It was concluded that due to the amount of data processing required and the longer work time of TLS, SLAM based MLS is a method that is worth further development as it provides unparalleled flexibility, safety improvements and work time efficiency.

Syftet med denna uppsats är att undersöka vilka risker som finns vid grundläggning av småhus. Metoden som användes var litteraturstudie av geotekniska risker vid stora projekt. Riskerna som återkom delades in i geologiska, mänskliga och ekonomiska faktorer. Därefter diskuterades om dessa risker även är aktuella för småhus. Bland de geologiska faktorerna ansågs inte markförhållanden utgöra en betydande riskkälla för småhus då dessa antingen är välkända eller mindre svåra att kontrollera på grund av husets begränsade utbredning på marken. Däremot är det mycket viktigt att känna till eventuell förekomst och omfattning av farliga ämnen eller egenskaper i omkringliggande mark. De mänskliga faktorerna var okunskap, brist på kommunikation, otydliga kontrakt och beslut av chefer. Några risker var att nödvändiga undersökningar inte görs eller att resultaten av de undersökningar som görs misstolkas. Risker för missförstånd mellan olika yrkesgrupper ansågs vara mindre då färre människor kommunicerar på ett småhusbygge, men risken att byggherren inte tolkar experters rekommendationer rätt bedömdes vara högre. Otydliga eller obefintliga kontrakt bedömdes vara vanligare. Slutsaten var att de största riskkällorna är marken och projektledaren. Detta är fördjupningsdelen i ett arbete som också innefattar projektering och dimensionering av ett småhus. / The purpose of this essay is to examine the risks associated with foundations of small houses. The method used in this paper was a literature study of geotechnical risks in large projects. Recurrent risks were divided into geological, human and economic factors. Thereafter it was discussed whether these risks could occur for small projects as well. Among the geological factors, soil conditions were not considered to be a significant source of risk for a small house since these are often well known or less difficult to inspect because of the limited expansion of a house on the ground. However, it is very important to be aware of possible presence and scope of dangerous elements or properties in the surroundings. The human factors identified were lack of knowledge, lack of communication, unclear contracts and management decisions. Some of the risks implied not performing the necessary investigation or misinterpretation of the obtained results. The risk of misunderstandings between different professions was considered to be lower as there are fewer workers involved, but the risk of a client not interpreting the recommendations made by an expert was deemed to be higher. Unclear or non-existing contracts were also assessed to be more common. The conclusion was that the greatest sources of risks are the ground and the project management

El objetivo de esta investigación fue examinar la relación entre los factores críticos de éxito del perfil de implementación del proyecto (PIP) con los criterios para medir el éxito del proyecto, y el grado en que varían las relaciones al ser moderadas por la experiencia, la certificación en gestión de proyectos, y el estilo de liderazgo transformacional del director de proyecto. El estudio fue no experimental, de naturaleza cuantitativa, y realizado en Perú y Ecuador para el sector de tecnologías de información (TI). Los datos fueron obtenidos por encuestas y modelados utilizando ecuaciones estructurales. Los resultados muestran que los factores críticos que explicaron el éxito fueron la aceptación del cliente, el equipo del proyecto, y la resolución de problemas. La experiencia del director de proyecto no es significativa y la certificación no incide en el éxito. Se concluye que durante el desarrollo de un proyecto es necesario combinar varios estilos de liderazgo. / The aim of this study was to examine the relationships between the critical success factors of the project implementation profile (PIP) with project success criteria and with the degree to which relationships vary when moderated by experience, management’s project approval, and the transformational leadership style of the project’s manager. This study was non-experimental, quantitative in nature, and was conducted in Peru and Ecuador in the information technology (IT) sector. Data were gathered through surveys and were modeled by using structural equations. The results showed that the critical factors that explained success were customer acceptance, project team, and problem solving. Project manager experience was not significant and certification had no relevance. It is concluded that during project development it is necessary to combine various leadership styles. Keywords: project success; critical; factors; criteria; transformational leadership style; certificatio