Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-10T21:25:15Z No. of bitstreams: 1 JoaoRonybertoCavalcanteRibeiro_DISSERT.pdf: 10659688 bytes, checksum: 7ec8ae4a93f2bbc61768b6aa5b4d8027 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-17T21:43:40Z (GMT) No. of bitstreams: 1 JoaoRonybertoCavalcanteRibeiro_DISSERT.pdf: 10659688 bytes, checksum: 7ec8ae4a93f2bbc61768b6aa5b4d8027 (MD5) / Made available in DSpace on 2016-03-17T21:43:41Z (GMT). No. of bitstreams: 1 JoaoRonybertoCavalcanteRibeiro_DISSERT.pdf: 10659688 bytes, checksum: 7ec8ae4a93f2bbc61768b6aa5b4d8027 (MD5) Previous issue date: 2015-02-27 / O litoral do Estado do Rio Grande do Norte ? caracterizada pela presen?a de dunas e fal?sias. Estas ?ltimas consistem em taludes com altura de at? 40 metros e inclina??o variando de 30o a 90o com a horizontal. Assim, esta disserta??o teve como objetivo a avalia??o da estabilidade da fal?sia da Ponta do Pirambu em Tibau do Sul/RN, e a realiza??o de um estudo param?trico sobre a estabilidade de uma fal?sia homog?nea considerando como vari?veis a coes?o do material, a altura da fal?sia e a inclina??o do talude. O estudo na Ponta do Pirambu considerou ainda a possibilidade da exist?ncia de uma cobertura coluvionar com espessura variando de 0,50 a 5,00 metros. As an?lises foram realizadas pelo m?todo de Bishop, utilizando o programa GEO5. Na an?lise param?trica foram produzidos gr?ficos que relacionam altura da fal?sia com a inclina??o, para fatores de seguran?a iguais a 1,00 e 1,50; al?m de gr?ficos onde ? poss?vel obter facilmente o menor fator de seguran?a a partir da coes?o, altura da fal?sia e sua inclina??o. Concluiu-se que esses gr?ficos s?o muito ?teis para an?lises preliminares, para a defini??o de ?reas cr?ticas em mapeamentos de riscos em ?reas de fal?sias e para determina??o de uma equa??o para obten??o do menor fator de seguran?a em fun??o dos par?metros de resist?ncia e da geometria de um talude. Em rela??o ? fal?sia da Ponta do Pirambu, os resultados mostraram que a fal?sia est? sujeita a deslizamentos superficiais localizados nos pontos onde pode haver a presen?a do col?vio com espessuras superiores a dois metros. Entretanto, a fal?sia se mant?m est?vel, apresentando fator de seguran?a global igual ou superior a 2,50 na condi??o saturada. / The coastline from Rio Grande do Norte state is characterized for the presence of dunes and cliffs. The latter consist of slopes with height up to 40 meters and inclinations ranging from 30? to 90? wich horizontal. Thus, this dissertation had as objective the evaluation of the stability of cliff from Ponta do Pirambu in Tibau do Sul/RN, and the realization of a parametric study on the stability of a homogeneous cliff considering as variables the material's cohesion, the cliff height and the slope inclination. The study in Ponta do Pirambu considered yet the possibility of the existence of a colluvial cover with thickness ranging from 0.50 to 5.00 meters. The analyzes were performed by Bishop method, using GEO5 software. In parametric analysis were produced graphics that relate height cliff with the inclination, to safety factors equals to 1.00 and 1.50; besides graphics where it is possible easily get the lowest safety factor as from the cohesion, cliff height and its inclination. It was concluded that these graphs are very useful to preliminary analyzes, for the definition of critical areas in risk mappings in areas of cliffs and for determination of an equation for obtaining the lowest safety factor function of the strength parameters and of slope geometry. Regarding the cliff from Ponta do Pirambu, the results showed that the cliff is subject to superficial landslides located in the points where may there be the presence of colluvium with thicknesses greater than two meters. However, the cliff remains stable presenting the global safety factor equal or superior to 2.50 in the saturated condition.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-11-03T20:42:55Z No. of bitstreams: 1 JoseEdsonDeAlmeidaJunior_DISSERT.pdf: 6070806 bytes, checksum: b15852e13e5be71af8ab041cf03063b8 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-11-17T00:14:16Z (GMT) No. of bitstreams: 1 JoseEdsonDeAlmeidaJunior_DISSERT.pdf: 6070806 bytes, checksum: b15852e13e5be71af8ab041cf03063b8 (MD5) / Made available in DSpace on 2017-11-17T00:14:16Z (GMT). No. of bitstreams: 1 JoseEdsonDeAlmeidaJunior_DISSERT.pdf: 6070806 bytes, checksum: b15852e13e5be71af8ab041cf03063b8 (MD5) Previous issue date: 2017-08-18 / O presente trabalho tem como objetivo a avalia??o multitemporal de curto prazo da retra??o numa fal?sia da Forma??o Barreiras, na ?rea do Centro de Lan?amento Barreira do Inferno (CLBI), localizada no litoral oriental do Estado do Rio Grande do Norte (RN). Os estudos foram conduzidos entre agosto de 2016 e fevereiro de 2017, com a utiliza??o do Laser Esc?ner Terrestre (LT), aparelho que utiliza o pulso laser para fazer o mapeamento da fal?sia. A primeira etapa do estudo usou os dados da nuvem de pontos levantada em 21 de agosto de 2016, para a constru??o de 10 Modelos Digitais do Terreno (MDT) em quatro diferentes softwares, para a sele??o do m?todo interpolador que melhor representa a superf?cie estudada. A segunda etapa consistiu na caracteriza??o da fal?sia quanto ao seu principal indutor erosivo, atrav?s da utiliza??o de 30 perfis transversais a face da fal?sia obtidos a partir dos MDTs, gerados na etapa anterior, resultando numa subdivis?o da fal?sia em 5 setores de acordo com esta caracteriza??o. As avalia??es e quantifica??o da eros?o total e da taxa de retra??o foram conduzidas a partir da compara??o entre os MDTs e perfis transversais gerados em cada um dos levantamentos. Os resultados mostraram que a fal?sia apresentou uma retra??o de aproximadamente 6 cm com uma eros?o total de 333 m? no per?odo de estudo. O resultado tamb?m mostrou a import?ncia de se avaliar a confiabilidade da nuvem de pontos com rela??o a presen?a de vazios, ocasionados por sombreamentos durante os levantamentos, que podem ser fontes de erros significativos. O estudo desta fal?sia se faz importante por ser o primeiro a utilizar o LT neste tipo de forma??o, como tamb?m por representar uma nova ferramenta para o entendimento da din?mica costeira. / This research aims a short-term multi-temporal evaluation of the seacliff retreat of the Barreiras Formation, in the Barreira do Inferno Launch Center (CLBI, in Portuguese) located in the eastern coast of Rio Grande do Norte (RN), Brazil. The studies were conducted between August 2016 and February 2017 through a Terrestrial Laser Scanning (TLS), which is equipment that utilizes a pulsed laser to map seacliffs face. The first phase of the study used the point cloud generated on August 21, 2016, for the construction of 10 Digital Elevation Model (DEM) via four different softwares for selecting the interpolation method that best represents the studied surface. The second phase was the description of the seacliff according to its main erosive cause through 30 transversal seacliff face profiles obtained through the DEM generated in the previous phase. It led to a subdivision of the seacliff in 5 segments according to its description. The evaluation and quantification of the net erosion and the retreat rate were conducted through comparing the DEMs with the transversal profiles generated. The results expressed that the seacliff had a retreat of approximately 6 centimeters with a net erosion of 333 m? during the study period. It was also observed the importance of evaluating the reliability of the point cloud because of the presence of blanks due to the shading during the data collection, which may cause significant errors. The evaluation of this seacliff was relevant not only because it was the first to be done through TLS in this type of formation, but also because it represents a new way for understanding the coast dynamic.