Assessment of slide surface and pre-slide topography using site investigation data in back analysis

A section of Highway 97, west of Vernon, B.C., is located over a soft-to-firm, compressible, silty clay subsoil. In addition to an extensive site investigation, the performance of two test embankments was observed for 2 years before construction was begun on the highway grade between them. When the highway fill reached a maximum thickness of about 10 m a failure occurred. The design was then changed to include berms on either side, but a second failure occurred when the grade was rebuilt. An undrained back-analysis of the first failure shows the influence of various variables on the factor of safety and illustrates the difficulty of choosing appropriate strength values for design when the site has a strong crust overlying a weaker layer and there is potential for progressive failure. Observations of settlements, pore pressures, and lateral movements in the subsoil describe the performance of the embankment during construction and reveal the importance of strain softening as a factor in the failures. Comparisons with a variety of similar failures in Canada, Scandinavia, and southeast Asia provide some guidance for future construction over similar materials. Key words : case history, embankment failure, field observation, pore pressures, stability, strength, undrained analysis.

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Pressuremeter Investigation for Mass Rapid Transit in Bangkok, Thailand

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198105192800122 ◽

2005 ◽

Vol 1928 (1) ◽

pp. 206-217 ◽

Cited By ~ 3

Author(s):

Richard E. Prust ◽

John Davies ◽

Shuang Hu

Keyword(s):

Back Analysis ◽

Site Investigation ◽

Design Parameters ◽

Soil Parameters ◽

Rapid Transit ◽

Underground Structures ◽

Ground Conditions ◽

Strength And Stiffness ◽

Slurry Walls ◽

Mass Rapid Transit

The 20-km (12.5-mi) mass rapid transit underground railway system in central Bangkok, Thailand, recently opened for passengers. During construction, the project was divided into two separate civil design–build contracts: the northern section, comprising approximately 10 km (6.2 mi) of twin bored tunnels, and nine stations constructed within slurry walls by adopting top-down techniques. A crucial part of the design of the underground structures was the selection of appropriate design parameters for the slurry walls. The contractor was responsible for ground-related issues and carried out a detailed site investigation to confirm the ground conditions and define soil parameters for the design of the underground structures. The site investigation comprised 40 conventional wash-bored borings and six self-boring pressuremeter tests. This paper describes the site investigation that was carried out for the project and the ground conditions that were encountered, with particular focus on the use of the self-boring pressuremeter to estimate the soil strength, stiffness, and in situ pressure for use in design of the slurry walls. The paper discusses the various methods used to interpret the data and compares the parameters derived from the pressuremeter to those derived from other methods and from back-analysis of the behavior of the wall during construction. It is concluded that in the conditions in Bangkok, the pressuremeter testing provided higher strength and stiffness values than determined from other methods and that these parameters were subsequently borne out by the behavior of the underground structures.

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Shallow penetrometer tests: theoretical and experimental modelling of penetration and dissipation stages

Canadian Geotechnical Journal ◽

10.1139/cgj-2018-0656 ◽

2020 ◽

Vol 57 (4) ◽

pp. 568-579 ◽

Cited By ~ 2

Author(s):

M.A. Schneider ◽

S.A. Stanier ◽

D.J. White ◽

M.F. Randolph

Keyword(s):

Back Analysis ◽

Site Investigation ◽

Shallow Foundation ◽

Foundation Design ◽

Experimental Modelling ◽

Fine Grained ◽

Core Samples ◽

Proof Testing ◽

A Site ◽

Multi Phase

Shallow penetrometers are devices that penetrate into and measure the properties of surficial offshore sediments via multi-phase tests involving penetration, dissipation, and rotation stages. In fine-grained soils such as silts and clays, these testing stages yield undrained strength, consolidation, and friction properties relevant to subsea pipeline and shallow foundation design. This paper describes toroid and hemiball devices of the scale for use in box-core samples and associated interpretation methods for the penetration and dissipation stages. The aim of the paper is to provide all tools needed to design and interpret these tests. New large-deformation finite element (LDFE) dissipation solutions are presented, which can be used for back-analysis of the dissipation stage. Results of an extensive laboratory proof testing exercise in kaolin clay, for both the hemiball and toroid penetrometers, are also reported. These results highlight the potential of the two devices to quickly and economically assess strength and consolidation characteristics of fine-grained sediments in box-core samples recovered to the deck of a site investigation vessel.

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Research of Slope Back Analysis Based on Inclination Monitoring Data

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.90-93.554 ◽

2011 ◽

Vol 90-93 ◽

pp. 554-558

Author(s):

Wan Li Chao ◽

Xing Hua Wang

Keyword(s):

Soil Layer ◽

Back Analysis ◽

Weight Coefficient ◽

Monitoring Data ◽

Weak Soil ◽

New Methods ◽

Slide Surface

Problem is brought forward by the weak soil layer and the soil near slide surface. The weight back analyzed is presented to solve the problem. For obtaining the weight coefficient, the division of the inclination curve is done. After that, the soil can be divided into several blocks. The displacement of the curve is described by two values: the sliding and the deformation displacement. The method of the weight coefficient calculation is proposed applying the deformation displacement. At last, the sensitivity of the new methods is calculated.

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Somatization Symptoms among Female Survivors of Sexual Violence: A Multi-Site Investigation

PsycEXTRA Dataset ◽

10.1037/e617962012-504 ◽

2008 ◽

Author(s):

Katie Edwards ◽

Megan Crawford ◽

Erin Tansill ◽

Megan Murphy ◽

Christine Gidycz ◽

...

Keyword(s):

Sexual Violence ◽

Site Investigation ◽

Female Survivors

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Lameness in weaned pigs associated with tetracycline overdose

Tierärztliche Praxis Ausgabe G Großtiere / Nutztiere ◽

10.1055/s-0038-1623152 ◽

2013 ◽

Vol 41 (01) ◽

pp. 61-66

Author(s):

P. Wolf ◽

J. Kamphues ◽

E. Grosse Beilage ◽

V. Gotter

Keyword(s):

Body Weight ◽

Site Investigation ◽

Weaned Pigs

SummaryOn a piglet producing farm severe lameness was observed in pigs which had been weaned 3 weeks and longer due to severe distortions of joints and claws of fore and/or hind legs. Splaying of claws as well as flexural limb deformations particularly in the carpal joints increased in degree the older and heavier the pigs were. Because of coughing in the weaners, which had started 7–8 weeks before any lameness or limb deformation had been apparent, tetracycline was applied via water as medication. During the course of an on-site investigation, a miscalculation of dosage – 129–168 mg tetracycline per kg body weight – was revealed. It was therefore suggested to the farmer and his veterinarian to immediately stop the application of tetracycline and to use a different antibiotic against the still present coughing and sneezing. During a follow-up evaluation 4 weeks later, the farmer reported a significant decrease in affected animals. While a direct correlation between the lameness in the weaned pigs and the tetracycline dosage could not be proven, the existing evidence supports the theory that the overdosage was at least a contributing factor.

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