Characterization of unsaturated zone susceptible to landslides in tropical volcanic residual soil with in-situ tests

2010 ◽  
pp. 727-732
Author(s):  
P Rahardjo ◽  
R Karlinasari
Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2313
Author(s):  
Maria Luisa Beconcini ◽  
Pietro Croce ◽  
Paolo Formichi ◽  
Filippo Landi ◽  
Benedetta Puccini

The evaluation of the shear behavior of masonry walls is a first fundamental step for the assessment of existing masonry structures in seismic zones. However, due to the complexity of modelling experimental behavior and the wide variety of masonry types characterizing historical structures, the definition of masonry’s mechanical behavior is still a critical issue. Since the possibility to perform in situ tests is very limited and often conflicting with the needs of preservation, the characterization of shear masonry behavior is generally based on reference values of mechanical properties provided in modern structural codes for recurrent masonry categories. In the paper, a combined test procedure for the experimental characterization of masonry mechanical parameters and the assessment of the shear behavior of masonry walls is presented together with the experimental results obtained on three stone masonry walls. The procedure consists of a combination of three different in situ tests to be performed on the investigated wall. First, a single flat jack test is executed to derive the normal compressive stress acting on the wall. Then a double flat jack test is carried out to estimate the elastic modulus. Finally, the proposed shear test is performed to derive the capacity curve and to estimate the shear modulus and the shear strength. The first results obtained in the experimental campaign carried out by the authors confirm the capability of the proposed methodology to assess the masonry mechanical parameters, reducing the uncertainty affecting the definition of capacity curves of walls and consequently the evaluation of seismic vulnerability of the investigated buildings.


1981 ◽  
Vol 6 ◽  
Author(s):  
Hans-Peter Hermansson ◽  
Hilbert Christensen ◽  
Lars Werme ◽  
Kaija Ollila ◽  
Rune Lundqwist

ABSTRACTThe planned Swedish KBS glass corrosion investigation program comprises experiments with inactive glasses containing simulated waste, prolonged in-situ tests, the characterization of corrosion products, immiscibility studies, and corrosion experiments with “hot” glass.This presentation gives a short description of the entire program. It focuses thereafter on some recent leaching results with the inactive KBS glass qualities ABS 39 and ABS 41, which were leached in a manner similar to the PNL MCC–1 test procedure.


2000 ◽  
Vol 37 (4) ◽  
pp. 796-810 ◽  
Author(s):  
F Schnaid ◽  
J AR Ortigao ◽  
F M Mántaras ◽  
R P Cunha ◽  
I MacGregor

This paper presents the analyses of the results of the site investigation programme carried out at the Kowloon Bay site in Hong Kong. The tests consisted of self-boring pressuremeter (SBPM), Marchetti dilatometer (DMT), and laboratory tests carried out in a granite saprolite, which can be described as a lightly cemented sand. The purpose of this research project is to stimulate the development of methods to interpret data obtained from tests in residual soils. In particular, the work aims to evaluate the analyses of the SBPM data through a curve-fitting technique. Both the loading and unloading portions of the SBPM curve were analysed and the results compared with those from other tests. The advantage of this analysis technique is the possibility of constructing a theoretical curve that reproduces a pressuremeter test from which a set of fundamental parameters can be derived, namely the friction angle, cohesion intercept, lateral stress, and shear modulus. The DMT proved to be a reliable tool that yielded good soil parameters at a small fraction of the cost of the other in situ tests.Key words: residual soil, in situ tests, pressuremeter, Marchetti dilatometer.


2001 ◽  
Vol 695 ◽  
Author(s):  
Aman Haque ◽  
Taher Saif

ABSTRACTWe present the uniaxial stress-strain response of a freestanding 100 nanometer thick 99.99% pure sputtered Aluminum film with grain size about 60 nanometers, tested in-situ inside a SEM chamber. The specimen is cofabricated with MEMS force and displacement sensors to minimize the experimental setup size, allowing both quantitative and in-situ tests to be performed in SEM and TEM chambers. The experimental results strongly suggest that at this size scale, a) Elastic modulus remains same as the bulk Aluminum, b) Yielding starts at about 625 MPa, and c) Strain hardening effect is absent, which indirectly suggests the deformation at this size scale is not dislocation mechanism based.


2008 ◽  
Vol 54 (185) ◽  
pp. 324-332 ◽  
Author(s):  
Philippe Berthet-Rambaud ◽  
Ali Limam ◽  
Djebar Baroudi ◽  
Emmanuel Thibert ◽  
Jean-Michel Taillandier

AbstractExperiments have been conducted on the French full-scale experimental site at Lautaret pass to improve our understanding of the action of snow avalanches on obstacles. The ultimate objective is to provide realistic pressure distribution models suitable for use in civil engineering design and to eliminate the restrictive assumptions currently used in this field. We focus on the feasibility of using the inverse method to quantify the action of the avalanche from its effects on realistic structures rather than from sensors placed directly in the flow. This approach takes into account the interactions between the flow and the obstacle and ensures that the result is effectively the action experienced by the obstacle. The inverse analysis procedure is developed and validated using both numerical and laboratory tests. In situ tests carried out at the Lautaret site to determine the avalanche action at different scales confirm the reliability of this original approach. Its intrinsic characteristics make it especially suitable for application to different structures to provide new knowledge in this complex field.


2020 ◽  
Vol 195 ◽  
pp. 01010
Author(s):  
Bilal Yoka Khail ◽  
Mathilde Morvan ◽  
Pierre Breul

As part of the rehabilitation work on the Gabonese railway line, the Trans-Gabon Railway, it was necessary to analyse the behaviour of the materials constituting the subgrade soil. These soils are pelitic soils whose behaviour under unsaturated conditions and cyclic loading has not been studied before and which present differential settlements and lack of bearing capacity. In this article, we focus on the characterization of the subgrade soil. The objective of this work is first to determine the in-situ characteristics of the pelitic soil and be able to link these characteristics with the behaviour studied in laboratory. For that purpose, we propose an in-situ investigation based on the use of light dynamic penetrometric tests in order to assess the variability of the subgrade layer and a drying-wetting test to assess the influence of hydric stress on the drainage path of the studied soil. We present the results of in-situ tests performed on a study area. We also present the results of the tests to determine the soil water characteristic curves (SWCC) and the curves describing the volumetric behaviour of this soil when exposed to drying.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Shuai Luan ◽  
Fenglai Wang ◽  
Tiehong Wang ◽  
Zhao Lu ◽  
Weihou Shui

Granite residual soil is widely distributed in south China and is treated as a special soil. Its design parameters in rotary drilling bored piles are a matter of debate due to lack of in-situ pile load tests. Back-analysis of test piles is a reliable means of studying the geotechnical capacity of granite residual soil for pile design. In this study, a series of in situ tests was conducted comprising six full-scale instrumented test piles in gravelly granite residual soil in Shenzhen to consider the effects of different construction methods. The six piles were constructed with three different rotary drilling methods. Two commonly used design methods were investigated in the back-analysis: the SPT and effective stress methods. The results of the loading tests and strain gauges were used to obtain the back-analyzed parameters of the ultimate shaft resistance and ultimate base resistance for gravelly granite residual soil with these two design methods.


Coatings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 330 ◽  
Author(s):  
Michela Ricca ◽  
Emilia Le Pera ◽  
Maurizio Licchelli ◽  
Andrea Macchia ◽  
Marco Malagodi ◽  
...  

This paper presents the results of a laboratory experimentation carried out on stone materials in the framework of the CRATI project (Knowledge and Restoration through Advanced Integrated Technologies) aimed at testing new products with consolidating properties by means of an integrated methodological approach. After the preliminary characterization of stone materials collected in the pilot site, the second stage of the activities within the project were focused on the formulation and testing of products for the conservation of the same materials against decay, especially salt crystallization, one of the most aggressive and common degrading processes. The San Domenico Church, located in the old town of Cosenza (Calabria, Southern Italy) has been chosen as the pilot site and for the in situ tests. Several specimens with the same features of the stone materials used in San Domenico church were collected from a historical quarry near the city of Cosenza. These specimens were treated and then artificially degraded by salt crystallization tests in order to evaluate their susceptibility to weathering intensity. Three different consolidating products were used; respectively, two commercial and another one formulated in laboratory: (a) a suspension of nanosilica (Nano Estel®); (b) a suspension of nanolime (CaLoSiL®), and (c) a suspension of nano calcium-hydroxide dispersed in isopropyl alcohol and then mixed with diammonium hydrogen phosphate. A systematic approach, including minero-petrographic, geochemical and physico-mechanical techniques, was applied to evaluate (a) the nature and main features of materials; (b) the efficacy of consolidating treatments, and (c) the resistance of treated stone to the salt crystallization processes. The tested products demonstrated a significant efficiency to consolidate and protect stone material samples, enhancing their resistance to salt crystallization. Thus, such a case history may be useful in order to plan appropriate restoration interventions that consider the interactions between the building stone and the protective/consolidating product.


DYNA ◽  
2018 ◽  
Vol 85 (206) ◽  
pp. 211-219 ◽  
Author(s):  
Breno Padovezi Rocha ◽  
Heraldo Luiz Giacheti

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