Determination of soil properties from standard penetration test complemented by torque measurement (SPT-T)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Development of a penetration test for timber impregnation products for use in old buildings

This paper studies the application of commercial biocides to old maritime pine timber structures (Pinus pinaster Ait.) that have previously been impregnated with other products. A method was developed in the laboratory to be used in situ to determine the impregnation depth achieved by a new generation biocide product applied to timber from an old building. This timber had once been treated with an unknown product difficult to characterize without extensive analysis. The test was initially developed in laboratory conditions and later tested on elements of the roof structure of an 18th century building. In both cases the results were promising and mutually consistent with penetration depths for some treatments reaching 2.0 cm. The application in situ proved the tests viability and simplicity of execution giving a clear indication on the feasibility of possible re-treatments.

Development of an in situ penetration test for the uptake of preservatives in applied wood

This paper concerns the study of biocides application in old timber structures of maritime pine (Pinus pinaster Ail.), previously impregnated with other products. A method was developed in laboratory to determine in situ the penetration depth of a product applied superficially. As initial treatment, three traditional products for sawn timber for buildings were used and, for new treatments, two newer, more environmentally benign products were used. Their ability to penetrate the pre-treated surfaces was evaluated after 1, 2 and 3 applications at 24 hours intervals and the results obtained are presented. Finally, the applicability of the developed test to the in-situ evaluation of timber structures is also discussed.

Genetic and Antigenic Analysis of Adenovirus Type 3 Strains Showing Intermediate Behavior in Standard Seroneutralization Test

During an epidemiological survey of acute respiratory infection in Rio de Janeiro, among 208 adenovirus isolates, we found two strains that we were not able, by a standard neutralization procedure, to distinguish between type 3 or 7. However, DNA restriction pattern for the two strains with different enzymes were analyzed and showed a typical Ad3h profile. Using a cross-neutralization test in which both Ad3p and Ad7p antisera were used in different concentration against 100 TCID50 of each adenovirus standard and both isolates, we were able to confirm that the two isolates belong to serotype 3. An hemagglutination inhibition test also corroborated the identification of both strains as adenovirus type 3. Comparing Ad3h and Ad3p genome, we observed 16 different restriction enzyme sites, three of which were located in genomic regions encoding polypeptides involved in neutralization sites

SPT-T: test procedure and applications

Ranzini (1988) proposed the Standard Penetration Test with torque measurement (SPT-T) and some geotechnical engineers in Brazil have been using it since 1991. This paper presents the state of the art on SPT-T testing, emphasizing what is already established as common knowledge in Brazilian engineering practice, besides a suggestion for test procedure, including equipment and practical aspects. In addition, the study of the shape of the torque versus rotation-degree angle curve obtained by an electric torquemeter used in several SPT-T tests carried out on six experimental research sites in the southeast region of Brazil is discussed here. Four different methods to predict pile capacity based on SPT-T test results are briefly presented and a comparison with load tests carried out on different types of piles, on those six experimental research sites, is presented.

Energy efficiency for standard penetration tests

The need for standardization of the measured blow count number N-spt into a normalized reference energy value is now fully recognized. The present paper extends the existing theoretical approach using the wave propagation theory as framework and introduces an analysis for large displacements enabling the influence of rod length in the measured N-spt values to be quantified. The study is based on both calibration chamber and field tests. Energy measurements are monitored in two different positions: below the anvil and above the sampler. Both experimental and numerical results demonstrate that whereas the energy delivered into the rod stem is expressed as a ratio of the theoretical free-fall energy of the hammer, the effective sampler energy is a function of the hammer height of fall, sampler permanent penetration, and weight of both hammer and rods. Influence of rod length is twofold and produces opposite effects: wave energy losses increase with increasing rod length and in a long rod composition the gain in potential energy from rod weight is significant and may partially compensate measured energy losses. Based on this revised approach, an analytical solution is proposed to calculate the energy delivered to the sampler and efficiency coefficients are suggested to account for energy losses during the energy transference process.

Theoretical and experimental evaluation of the influence of the length of drill rods in the SPT-T test

The influence of soil drill rod length on the N value in the SPT-T test has been studied extensively by Mello (1971), Schmertmann & Palacios (1979), Odebrecht et al. (2002) and Cavalcante (2002). This paper presents an analysis of the Standard Penetration Test supplemented with torque measurement (SPT-T). A theoretical study of the resistance of the rod material to torsion and bending indicated that the shear stress caused by the rod self-weight represents less than 1% of that caused by the torsional moment. An experimental study with electric torquemeters attached to a horizontal rod system, as well as two field tests in the vertical direction, were also carried out to compare and substantiate the results. The purpose of these tests was to analyze changes along the length of the rod in response to successive increments at 1-meter intervals. Torque measurements were taken at each increment of the length to ascertain the accuracy of the theoretical data. The difference between the applied torque and the measured torque at the end of rod system was lower than the minimum scale of mechanical torquemeters used in practice.

Is perioperative point-of-care prothrombin time testing accurate compared to the standard laboratory test?

There is no accepted way of measuring prothrombin time without time loss for patients undergoing major surgery who are at risk of intraoperative dilution and consumption coagulopathy due to bleeding and volume replacement with crystalloids or colloids. Decisions to transfuse fresh frozen plasma and procoagulatory drugs have to rely on clinical judgment in these situations. Point-of-care devices are considerably faster than the standard laboratory methods. In this study we assessed the accuracy of a Point-of-care (PoC) device measuring prothrombin time compared to the standard laboratory method. Patients undergoing major surgery and intensive care unit patients were included. PoC prothrombin time was measured by CoaguChek XS Plus (Roche Diagnostics, Switzerland). PoC and reference tests were performed independently and interpreted under blinded conditions. Using a cut-off prothrombin time of 50%, we calculated diagnostic accuracy measures, plotted a receiver operating characteristic (ROC) curve and tested for equivalence between the two methods. PoC sensitivity and specificity were 95% (95% CI 77%, 100%) and 95% (95% CI 91%, 98%) respectively. The negative likelihood ratio was 0.05 (95% CI 0.01, 0.32). The positive likelihood ratio was 19.57 (95% CI 10.62, 36.06). The area under the ROC curve was 0.988. Equivalence between the two methods was confirmed. CoaguChek XS Plus is a rapid and highly accurate test compared with the reference test. These findings suggest that PoC testing will be useful for monitoring intraoperative prothrombin time when coagulopathy is suspected. It could lead to a more rational use of expensive and limited blood bank resources.

Background study on the development of a standard leaching test /

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Ricerca delle vulnerabilità e Penetration Test per Architetture Serverless

Il lavoro di tesi proposto è volto allo studio delle architetture Serverless, strutture che permettono agli sviluppatori di comporre facilmente applicazioni distribuite su molti servizi all’interno di un cloud, senza la necessità di gestire il server. Più nello specifico sono state studiate le FaaS (Function-as-a-Service), un modello di elaborazione cloud basato su eventi in cui il codice viene distribuito in container gestiti dalla piattaforma, e successivamente eseguito on-demand. A seguito di una prima parte di ricerca dello stato dell'arte, l'attenzione si è spostata sulla ricerca di vulnerabilità nel contesto del servizio OpenFaaS, un framework open-source che permette agli sviluppatori di distribuire facilmente funzioni e microservizi. Il deployment è stato fatto faasd, quest’ultimo è una semplificazione di OpenFaaS, usa le stesse componenti e lo stesso ecosistema di OpenFaaS ma usa Containerd al posto di Kubernetes. Dopo una prima fase di installazione e log-in il lavoro si è concentrato nelle varie metodologie di penetration test, nonché di ricerca delle vulnerabilità di sicurezza associate a tale paradigma. In informatica, il penetration test è il processo operativo di analisi o valutazione della sicurezza di un sistema o di una rete, simulando l'attacco di un potenziale utente malintenzionato. Nell'ultima fase sono stati condotti vari tentativi di attacco al sistema OpenFaaS tramite l'ausilio di alcuni tool. Inizialmente è stata fatta un'analisi della rete e del traffico tramite tool quali NMAP e Wireshark, per comprenderne meglio la struttura e come faasd creasse le funzioni a partire dai container. Infine, tramite OpenFaaS sono state create delle funzioni per testare la sicurezza e l'affidabilità di quest'ultima. In particolare, le funzioni indagano all'interno dei container al fine di comprendere la possibilità di eseguire code injection e rilevare possibili dati sensibili nel filesystem dell'immagine Docker così come nelle variabili d'ambiente.

La relació entre el valor N30 de L'SPT i la resistència a la compressió simple

The unconfined compression strength is a geotechnical parameter frequently used to determine the bearing capacity of foundations on clayey soils. Its value can be obtained from the unconfined compression test and, among several in situ tests, the standard penetration test (SPT). However, a comparison between the values of such a strength determined by both tests in CL, CL-ML and CH soils shows that it does not exist an approximate relationship. In any case it is remarkable that values of the test conducted in the laboratory fit between the lower and the higher ones calculated from the standard penetration number. This is very important for those geotechnical reports in which the unconfined compression strength is only based on the SPT. In this way, if the lower value is taken to evaluate the ultimate soilbearing capacity the result will not be very accurate but it will probably be by the side of safety

La relació entre el valor N30 de L'SPT i la resistència a la compressió simple

The unconfined compression strength is a geotechnical parameter frequently used to determine the bearing capacity of foundations on clayey soils. Its value can be obtained from the unconfined compression test and, among several in situ tests, the standard penetration test (SPT). However, a comparison between the values of such a strength determined by both tests in CL, CL-ML and CH soils shows that it does not exist an approximate relationship. In any case it is remarkable that values of the test conducted in the laboratory fit between the lower and the higher ones calculated from the standard penetration number. This is very important for those geotechnical reports in which the unconfined compression strength is only based on the SPT. In this way, if the lower value is taken to evaluate the ultimate soilbearing capacity the result will not be very accurate but it will probably be by the side of safety

O estudo geoestatístico de sondagens spt para geração de mapas auxiliares em obras de engenharia

A sondagem com SPT ("Standard Penetration Test") é o método de investigação com mais freqüência empregado na caracterização geotécnica de solos. Devido a relevância desse tipo de ensaio, desenvolveu-se um procedimento para geração de mapas de SPT com base em métodos geoestatísticos. Esses mapas devem conter a estimativa do índice de penetração (SPT) em diferentes posições no terreno em estudo, partindo de ensaios pré-existentes, objetivando auxiliar de maneira mais efetiva o planejamento de obras de engenharia. O trabalho foi baseado em um banco de dados com 141 sondagens realizadas na cidade de Passo Fundo/RS, compreendendo uma área total de 4,16km2. O banco de dados compreende sondagens de uma única empresa (o que minimiza os erros decorrentes da própria sondagem SPT) e uma única unidade geotécnica. Essas informações foram utilizadas para a avaliação do comportamento espacial dos parâmetros modelados e, posteriormente, construção de mapas de SPT. As estimativas foram efetuadas por krigagem ordinária em blocos com dimensões de 100mx100m, em quatro níveis distintos definidos de acordo com a variação média do índice de penetração com a profundidade Os mapas resultantes da krigagem ordinária revelaram-se satisfatórios para o fim a que se destina esse trabalho. Para a avaliação desses mapas, é relevante que se quantifiquem as incertezas associadas a essas estimativas. A metodologia para tal é baseada em Simulação Geoestatística, onde foram efetuadas simulações seqüenciais Gaussianas (ssG), em blocos de mesma dimensão que a utilizada na krigagem. Os resultados positivos mostraram ser adequado o emprego da simulação seqüencial Gaussiana, para geração de mapas auxiliares de valores de SPT a serem empregados no planejamento de investigações geotécnicas complementares.