O avanço das técnicas de melhoramento de solos vem permitindo o aproveitamento de locais nos quais, até pouco tempo atrás, era considerada a construção de muitas estruturas como inviáveis, seja técnica, financeira ou ambientalmente. Uma das técnicas que tem conseguido demostrar bons resultados é o reforço com fibras de diferentes origens, com ou sem presença de algum agente cimentante. A maioria dos estudos conduzidos sobre este tipo de materiais se têm centrado na caracterização dos materiais sob cargas estáticas, e outros estudos se limitam a avaliar o comportamento sob cargas cíclicas destes materiais para densidades relativas baixas, nas quais o fenômeno de liquefação governa o mecanismo de ruptura. O presente estudo tenta aprofundar no conhecimento sobre materiais compactos quando submetidos a carregamentos cíclicos, de maneira a fornecer insumos para o estudo deste campo. O estudo, de caráter experimental, foi feito através da caracterização de corpos de prova de areia e areia com 0,5% de fibras, além da consideração de dois índices de vazios: o primeiro de 0,63 (correspondente a uma densidade relativa de 90%), e o segundo com um índice de vazios igual a 0,75 (correspondente a uma densidade relativa de 50%) Foram executados 29 ensaios triaxiais, além da adoção dos valores de outros 15 feitos por outro autor, totalizando 44 ensaios. A totalidade dos ensaios divide-se assim: 12 ensaios monotônicos CID, 12 ensaios monotônicos CIU, e 20 ensaios cíclicos CIU sob tensão controlada. Nos ensaios monotônicos obtiveram-se incrementos no ângulo de atrito do material composto, sendo mais evidente para as amostras compactas. Em relação aos ensaios cíclicos, obteve-se incrementos nas resistência do material até atingir sua condição de ruptura, seja por liquefação em amostras pouco compactas (Dr= 50%), ou por mobilidade cíclica no caso de amostras compactas (Dr= 90%). A normalização dos resultados permitiu observar que, embora as fibras melhorem o desempenho das misturas quando submetidas a carregamentos cíclicos, não alteraram a estrutura do material em sua resposta em termos de módulo de elasticidade, pelo menos no que respeita a níveis de deformações medianos a grandes. Para pequenas deformações, evidenciou-se uma diminuição na rigidez das amostras, ocasionando assim maiores acréscimos de poropressão nos estágios iniciais dos ensaios, mais nas em areias com fibras do que sem elas. / The development of ground improvement techniques has allowed the use of certain places, which was in the past considered as non-viable for the construction of many types of structures. Fiber reinforced soils have shown good results, with or without presence of any cementitious agent. The focus of most studies performed on this type of materials, is the characterization under static loading, and other studies are limited to evaluating its behavior on cyclic loading at low level of relative density, in which cases the liquefaction phenomenon governs the mechanism of rupture. This study aims to improve the knowledge of cyclic loading effects in dense materials. Was carried out an experimental program by characterizing specimens of sand with 0% and 0.5% of randomly distributed fiber, considering two void ratios: 0.63 (dense sand, Dr = 90%) and 0.75 (moderately loose sand, Dr = 50%). In total, were performed 29 triaxial tests, in addition of another 15 executed by another author, totaling 44 The test were divided as follows: 12 monotonic CIU test, 12 monotonic CID test, and 20 CIU loading controlled cyclic test. In monotonic conditions, fibers addition increases the friction angle, mostly on dense samples (Dr = 90%) than on loose specimens (Dr = 50%). For cyclic tests, in both materials, fiber additions causes improvement on cyclic behavior, but with different failure mechanism, liquefaction for loose, and cyclic mobility for dense sands, regardless of the presence of fibers. The transformation of the number of cycles axis, or normalization of another cyclic results allowed observing that, despite the fiber addition can cause improvement of materials subjected to cyclic loading, the structure of the material did not change in elasticity modulus response, at least for medium to large strains levels. For small strains, occur a decrease in the stiffness of samples, causing greater increases of pore pressure in the initial stages of tests, more in reinforced sand than for none reinforced condition. / El avance de las técnicas para mejoramiento de suelos ha permitido el aprovechamiento de sitios en los cuales, hasta hace poco tiempo, se consideraba como no viable la construcción de muchas estructuras, sea por cuestiones técnicas, financieras o ambientales. Una técnica que ha demostrado buenos resultados es la incorporación de refuerzos con fibras de diferente origen, considerando o no la presencia de algún agente cementante. La mayoría de los estudios realizados a este tipo de materiales se han centrado en la caracterización bajo la acción de cargas estáticas, e otros se han limitado a evaluar el comportamiento bajo la acción de cargas cíclicas considerando únicamente densidades relativas bajas, para las cuales la ruptura está controlada por el fenómeno de licuación. El presente estudio busca ahondar en el conocimiento sobre el comportamiento bajo acción de cargas cíclicas de materiales compactos, buscando con ello ampliar la base experimental sobre este campo. El estudio, de carácter experimental, fue realizado a partir de la caracterización de especímenes de arena sin fibras y con 0,5% de fibras, además de la consideración de dos relaciones de vacíos: 0.63 (correspondiente a una densidad relativa de 90%), y 0,75 (correspondiente a una densidad relativa de 50%) Fueron realizados 29 ensayos triaxiales, además de haber adoptado los resultados de otros 15 realizados por otro autor, totalizando 44 ensayos. Los ensayos fueron divididos así: 12 ensayos monotónicos CID, 12 ensayos monotónicos CIU, y 20 ensayos triaxiales cíclicos CID con control de esfuerzos. En los ensayos monotónicos fueron obtenidos incrementos en el ángulo de fricción del material compuesto, siendo esta situación más evidente en muestras compactas. Con relación a los ensayos cíclicos, se obtuvo incremento en la resistencia de las muestras hasta alcanzar su condición de ruptura, bien sea por licuación (materiales relativamente sueltos, Dr = 50%), o por movilidad cíclica (materiales compactos, Dr = 90%). La normalización de los resultados permitió observar que, aunque las fibras mejoran el desempeño bajo cargas cíclicas de los materiales, no alteraron la estructura del material en términos de módulo de elasticidad, por lo menos para niveles medios y altos de deformación. Para pequeñas deformaciones, se evidenció una disminución en la rigidez de las muestras, lo que produjo mayores incrementos en las presiones de poros durante las fases iniciales de los ensayos, con mayor visibilidad en las arenas con fibras que cuando no hubo adición.

Solid Waste Management is one of the essential services provided by local bodies to keep the urban areas clean. Often it is poorly rendered as it is unscientific, out-dated and inefficient. With the rapid increase in population, livening standards, the generation rates of solid waste are increasing drastically. The landfill waste includes both organic and inorganic wastes as it is not often effectively segregated before disposal. The problem is acute in developing countries such as India. Bangalore city, with a population of about 10.18 million and more than 2000 industries, generates about 4,500 TPD of municipal solid waste. Of this Presently, various municipal solid waste processing units in Bangalore can handle only about 2100 TPD of waste. Mavallipura landfill developed and operated by M/s. Ramky Environmental Engineers, located 40 km away from Bangalore, is being used for disposing of about 1000 TPD, the installed capacity being only 600 TPD of waste. There are also a few dumps in around Bangalore due to historical reasons and insufficient capacity of various designated landfills. To reclaim the old dump sites/closed landfill sites for infrastructural development, it is necessary to know their geotechnical characteristics. Within the Landfill, the characteristics of the waste may change with depth due to degraded wastes as it has been dumped over a period of time. The physical parameters, chemical properties as well as the geotechnical behaviour of the waste change with depth. MSW is known to be a heterogeneous material of varying constituent types and dimensions, containing elements that degrade with time. To consider MSW as a geo-material to support the foundation of structures such as buildings and pavement, an analysis of the bearing capacity of the foundation and further long-term settlement of MSW is essential. The MSW samples are retrieved from a Mavallipura landfill site, Bangalore and analysed for important geotechnical properties such as compaction characteristics, shear strength, permeability, compressibility behaviour and dynamic properties of MSW using ultrasonic and cyclic triaxial tests. This research thus aims to provide valuable information about landfill sites for reclamation, closure and infrastructural development after the closure of landfills. Scanty data are available on the geotechnical properties of waste from landfill sites with varying degrees of degradation. This landfill site is selected as there is a huge environmental concern regarding the soil and groundwater contamination in the area and also can represent a typical landfill scenario in tropical regions. Quantification, quality assessment, consequent treatment and management of leachate have become a monstrous problem world over. In this context, the present study envisages to study the physicochemical and biological characterization of representative urban municipal landfill leachate and nearby water bodies and attempts to figure out relationships between the various parameters together with understanding the various processes for chemical transformations. The analysis shows intermediate leachate age (5-10 years) with higher nutrient levels i.e. 10,000 - 12,000 mg/l and ~2,000 - 3,000 mg/l of carbon (COD) and nitrogen (TKN) respectively. Elemental analysis and underlying mechanisms reveal chemical precipitation and co-precipitation as the vital processes in leachate pond systems resulting in accumulation of trace metals in these systems. The microbial analysis also correlated with specific factors relevant to redox environments that show a gradient in nature and the abundance of biotic diversity with a change in leachate environment. Finally, the quality and the contamination potential of the sampled leachate were performed with the help of potential leachate index (LPI) analysis and water quality index (WQI) analysis for surrounding water bodies (namely surface pond and open well) of Mavallipura landfill site. A geotechnical testing program has been drawn to evaluate the engineering properties of municipal solid waste samples retrieved from a landfill at Mavallipura at various depths through augur within the landfill dumped area. Laboratory studies included are composition, moisture content, particle size analysis, compaction, permeability, direct shear test, consolidation, triaxial compression test. For the laboratory tests, we had considered maximum particle sizes of less than 4.75 mm only. Standard Proctor Compaction tests yielded a maximum dry density of 7.0kN/m3 at 50% optimum moisture content. The permeability of MSW results shows in the range of 4x10-4 cm/sec. Compression index of MSW is 0.46980 and recompression index of MSW is 0.09454. Results obtained from the rectangular hyperbola method are compared with Casagrande and Taylor methods to prove that this method is reliable equally, and results are reasonably accurate. Based on direct shear tests, the MSW sample exhibited continuous strength gain with an increase in shear strain (16%) to define strength. The cohesion of MSW was 10kPa and friction angle is 34°. Based on the elastic constants results obtained from the direct shear test found to be very soft material. In the triaxial test, the MSW sample exhibited continuous strength gain with an increase in axial strain. The frictional component is increased due to sliding and rolling of fibrous particles over one another resulting in the development of apparent cohesion due to antiparticle bonds within the MSW material. Landfills are an integral part of waste management, and disastrous consequences can happen if seismic vulnerability of these landfills is not considered. Dynamic properties of MSW are required to perform seismic response analysis of MSW landfills, but there is no good understanding of the dynamic shear strength of MSW in literature. A comprehensive laboratory cyclic triaxial testing program has been taken up to determine the properties at different densities, confining pressures and shear strains. MSW degrades with time, and its shear modulus and damping are expected to vary with time and degradation. For the density of 6 kN/m3 the dynamic shear modulus values for MSW varied from 0.68 MPa to 5.38 MPa and damping ratio varied from 20% to 40% for MSW. For the density of 7 kN/m3 the dynamic shear modulus values for MSW varied from 1.8 MPa to 7.5 MPa and Damping ratio varied from 23% to 40% for MSW. For the density of 8kN/m3 dynamic shear modulus values for MSW varied from 2.46 MPa to 8.00MPa and damping ratio varied from 16% to 33% for MSW. Also, the ultrasonic testing method was used for determining the dynamic properties at low strains. The Ultrasonic test results indicated that with an increase in density of the sample and with decreased void ratio, the pulse propagation velocity (Vp) increases. With an increase in the density, the shear wave velocity and elastic constants (elastic modulus and shear modulus) increase. The elastic constant values obtained from the ultrasonic test are higher compared to values obtained from unconsolidated-undrained triaxial tests. Also, the carbon stored in the buried organic matter in Mavallipura landfill is estimated. Total organic carbon increases steeply with an increase in depth and is significantly high at a depth of 6 m. Subsurface properties cannot be specified but must be analysed through in-situ tests. The in-situ testing that are carried out in a landfill are boring, sampling, standard penetration test (SPT), dynamic cone penetration test (DCPT) and plate load tests (under static and cyclic condition). A correlation between corrected SPT ‘N’ values and measured using shear wave velocities has been developed for Mavallipura landfill site. Results show that the corrected SPT- N values increase with depth. Corrected N-values are used in the landfill design, so they are consistent with the design method, and correlations are useful. The results obtained from the dynamic cone penetration tests shows lower value when to compare with standard penetration test. The unit weight profile with depth ranged from a low unit weight of 2.48 kN/m3 near the surface to a highest value of approximately 9.02 kN/m3 at a depth of 6 m. The highest temperatures for landfills were reported at mid-waste elevations with temperatures decreasing near the top. The bearing pressure-settlement curves for plate size 75cm and 60cm presented similar behaviour while the plate size of 60cm curve presents a lesser settlement of 70mm, compared to with plate size of the 75cm curve with the settlement of 80mm and failure mode could be classified as punching shear. The cyclic plate load test with plate size of 60cm and 75cm were carried out on the soil cover. The elastic constants were found to be 73.87 and 96.84 kPa/mm and for 60 and 75cm plates respectively. Geophysical testing may not be as precise but has the benefit of covering large areas at small costs and sometimes can locate features that might be missing by conventional borings. Multichannel analysis of surface waves (MASW) is an indirect geophysical method used in the landfill for the characterization of the municipal solid waste site. The Mavallipura landfill was surveyed up to the length of about 35m at the top level. A series of one-dimensional and two-dimensional MASW surveys used active seismic sources such as sledgehammer (5kg) and propelled energy generator (PEG-40) was used. This hammer was instrumented with geophones to trigger record time. All the testing has been carried out with geophone spacing of 1m and recorded surface wave arrivals using the source to first receiver distance as 5m with recording length of 1000 millisecond and the recording sampling interval of 0.5 milliseconds (ms) were applied. Results shows that the PEG-40 hammer can generate the longest wavelength with a maximum depth of penetration. The shear wave velocity varies from 75 to 155 m/s with an increase in depth of about 27.5m. Based on the site characterization at the landfill site, it was found that the Mavallipura landfill site can be categorized as very loose, and it is still in a continued stage of degradation. Shear wave and P-wave velocity profile for eight major locations in the study area were determined and variation of waste material stiffness corresponding to the in-situ state with depth, was also evaluated. Also, MASW survey has been carried out to develop dispersion curve on another landfill site at Bhandewadi, Nagpur. MASW system consisting of 24 channels geode seismograph with 24 geophones of 4.5Hz capacity is used in this investigation. The seismic waves were created by sledgehammer with 30cmx 30cmx2cm size hammer plate with ten shots. These waves were captured by the geophones/receivers and further analyzed by inversion. The results indicated that near surface soils(less than 3m depth) approximately the to 5mm, and with 85% of dry weight basis of waste particles with sizes less than 10mm, the shear wave velocity varies from 75 to 140 m/s (frequency ranges from 30 to 23Hz). With the increase in 6.5m depth, the shear wave velocity ranged from 140 to 225m/s (frequency ranges 23 to 13Hz). Overall, the results of the study showed that seismic surveys have the potential to capture the changes in dynamic properties like shear wave velocity and Poisson’s ratio of the depth of MSW landfill to infer the extent of degradation and provide dynamic properties needed for seismic stability evaluations. Based on the in situ and laboratory results of this study and a review of the literature, the unit weight, shear wave velocity, strain-dependent normalized shear modulus reduction and material damping ratio relationships for Mavallipura landfill are developed and also validated using semi-empirical methods. Finally, seismic response analysis of Mavallipura landfill has been carried out using the computer programs like SHAKE 2000 and DEEPSOIL. Results show that the unit weight is increased with depth in response to the increase in overburden stress. The proposed material damping ratio and normalized shear modulus reduction curve lie close to the profile given in the literature for landfills composed of waste materials with 100% particles sized less than 20mm. Peak spectral acceleration at 5% damping value is 0.7g for 0.07 sec in SHAKE 2000 and peak spectral acceleration at 5% damping value is 0.63g for 0.04 sec in DEEPSOIL. Amplification ratio is 6.11 at 1.1l Hz in SHAKE2000 and 4.65 at 2.67Hz in DEEPSOIL. Peak ground acceleration (PGA) for the landfill site, it is observed PGA has decreased from 0.3g to 0.15g in DEEPSOIL and PGA has decreased from 0.33g to 0.15g in SHAKE2000. The studies presented in the thesis brought out the importance of characterization of municipal solid waste leachate regarding metabolism and treatment/degradation of Mavallipura landfill leachate. For municipal solid waste of with sizes ranging from 0.08 coefficient of permeability being about 10-4 cm/sec, the compression index was about 0.47. A more reliable method of calculating the coefficient of consolidation has been recommended. Correlations between shear wave velocity and SPT-N values has been developed for the Mavallipura landfill site. The results showed that the dynamic cone penetration tests values are lower than indicated by standard penetration tests. The cyclic plate load tests carried out with plate sizes of 75cm and 60cm showed that elastic constants of 96.84 kPa/mm and 73.87kPa/mm respectively. MSW properties evaluated in this thesis are compared with those of soft clays. The MSW properties showed higher values (strength and SBC) and lower values of compressibility, compared with those of soft clays. Thus foundation improvement on MSW is less challenging than foundations on soft soils. Also stabilization of MSW with other solid wastes such as fly ash can be considered as an economical option. Based on detailed studies the importance of unit weight, shear wave velocity, strain-dependent normalized shear modulus reduction and material damping ratio relationships for landfill waste have been developed. Based on the site characterization, the waste landfill has been categorized as very loose material, which is still in a degradation process. SHAKE2000 software shows higher PGA value comparing with DEEPSOIL.

The thesis deals with the experimental determination of the resilient modulus using cyclic triaxial test with the selected unbound mixtures of the base course of the pavement. The aim is to verify whether the proposed modulus-resilient in the regulation TP 170 based on the statisticaly verified data dating several decades ago is still valid in the present. Furthermore, the thesis deals with the dependence between the measured and the calculated values of the modulus resilient Mr from the cyclic triaxial test and the California Bearing Ratio tests. For the classification of the selected materials, further tests are used in the thesis, such as granularity and compaction tests.

In the theoretical part of the thesis are generally characterized hydraulically bound mixtures, their types, classification systems, manufacturing technology and the laying. There are also described experiences from abroad with the use secondary and recycled materials in hydraulically bound mixtures. The practical part deals with the experimental verification of the possibility of the use of secondary materials in hydraulically bound mixtures in construction of road infrastructure. In road laboratory Institute of road structures Brno university of technology was the five proposed mixtures, an assessment of their parameters with regard to the possibility of using these mixtures in the road sub-base layers. The work is also aimed at comparison of results elasticity modules reached laboratory testing and experimental measurements on road polygon.