Design of laterally loaded piles in clays based on cone penetration test data: a reliability-based approach

The behaviour of laterally loaded piles is considerably influenced by the uncertainties in soil properties. Hence probabilistic models for assessment of allowable lateral load are necessary. Cone penetration test (CPT) data are often used to determine soil strength parameters, whereby the allowable lateral load of the pile is computed. In the present study, the maximum lateral displacement and moment of the pile are obtained based on the coefficient of subgrade reaction approach, considering the nonlinear soil behaviour in undrained clay. The coefficient of subgrade reaction is related to the undrained shear strength of soil, which can be obtained from CPT data. The soil medium is modelled as a one-dimensional random field along the depth, and it is described by the standard deviation and scale of fluctuation of the undrained shear strength of soil. Inherent soil variability, measurement uncertainty and transformation uncertainty are taken into consideration. The statistics of maximum lateral deflection and moment are obtained using the first-order, second-moment technique. Hasofer-Lind reliability indices for component and system failure criteria, based on the allowable lateral displacement and moment capacity of the pile section, are evaluated. The geotechnical database from the Konaseema site in India is used as a case example. It is shown that the reliability-based design approach for pile foundations, considering the spatial variability of soil, permits a rational choice of allowable lateral loads.

Study of reliability of fibre Bragg grating fibre optic strain sensors for field-test applications

In this paper, the reliability and thus the suitability of optical fibre strain sensors for surface strain measurement in concrete structures was investigated. Two different configurations of optical strain sensors were used each having different mountings making them suitable for different uses in various structures. Due to the very limited time available to install the sensors and take result, commercially packaged sensors were used. In the tests carried out each sensor was mounted onto a concrete beam which was then subjected to a range of known and calibrated loadings. The performance of the optical strain sensors thus evaluated was compared with the results of conventional techniques. This comparison allows for selecting the best performing combination of sensor/mounting, i.e. long-gauge sensor with mounts bolted to threaded rods glued into the concrete for use in future work in a field test where a limited time window was available for installation, testing and post-test demounting. © 2012 Elsevier B.V.

Validity and Test –retest Reliability of the TIVRE-Basket® Test for the Determination of Aerobic Power in Elite Male Basketball Players

The aims of this study were to 1) determine the relationship between performance on the court-based TIVRE-Basket® test and peak aerobic power determined from a criterion lab-based incremental treadmill test and 2) to examine the test-retest reliability of the TIVRE-Basket® test in elite male basketball players. To address aim 1, 36 elite male basketball players (age 25.2 + 4.7 years, weight 94.1 + 11.4 kg, height 195.83 + 9.6 cm) completed a graded treadmill exercise test and the TIVRE-Basket® within 72 hours. Mean distance recorded during the TIVRE-Basket® test was 4001.8 + 176.4m, and mean VO2 peak was 54.7 + 2.8 ml.kg.min-1, and the correlation between the two parameters was r=0.824 (P= <0.001). Linear regression analysis identified TIVRE-Basket® distance (m) as the only unique predictor of VO2 peak in a single variable plus constant model: VO2 peak = 2.595 + ((0.13* TIVRE-Basket® distance (m)). Performance on the TIVRE-Basket® test accounted for 67.8% of the variance in VO2 peak (t=8.466, P=<.001, 95% CI 0.01 - 0.016, SEE 1.61). To address aim 2, 20 male basketball players (age 26.7±4.2; height 1.94±0.92; weight 94.0±9.1) performed the TIVRE-Basket® test on two occasions. There was no significant difference in total distance covered between Trial 1 (4138.8 + 677.3m) and Trial 2 (4188.0 + 648.8m; t = 0.5798, P = 0.5688). Mean difference between trials was 49.2 + 399.5m, with an ICC of 0.85 suggesting a moderate level of reliability. Standardised TEM was 0.88%, representing a moderate degree of trial to trial error, and the CV was 6.3%. The TIVRE-Basket® test therefore represents a valid and moderately reliable court-based sport-specific test of aerobic power for use with individuals and teams of elite level male basketball players. Future research is required to ascertain its validity and reliability in other basketball populations e.g. across age groups, at different levels of competition, in females and in different forms of the game e.g. wheelchair basketball.

The reliability of an isometric test based on constant perception of effort

To date there is no documented procedure to extrapolate findings of an isometric nature to a whole body performance setting. The purpose of this study was to quantify the reliability of perceived exertion to control neuromuscular output during an isometric contraction. 21 varsity athletes completed a maximal voluntary contraction and a 2 min constant force contraction at both the start and end of the study. Between pre and post testing all participants completed a 2 min constant perceived exertion contraction once a day for 4 days. Intra-class correlation coefficient (R=O.949) and standard error of measurement (SEM=5.12 Nm) concluded that the isometric contraction was reliable. Limits of agreement demonstrated only moderate initial reliability, yet with smaller limits towards the end of 4 training sessions. In conclusion, athlete's na"ive to a constant effort isometric contraction will produce reliable and acceptably stable results after 1 familiarization sessions has been completed.

Test-retest reliability of distortion product otoacoustic emissions in high-risk registry neonates

This paper studies the test-retest reliability of distortion product otoacoustic emissions (DPOAE) in newborns in a neonatal intensive care unit.

The reliability and validity of monitored connected discourse as a test of the threshold of intelligibility

This paper discusses a study undertaken to determine whether a normal hearing person or hearing impaired person can reliably select a threshold of intelligibility and if so, whether this can be considered a valid measurement.

Test-retest reliability with the Madsen ZO70 electroacoustic impedance bridge

This paper is a review of a study to measure acoustic impedance of the ear using a Madsen ZO70 bridge model.

Gaze stabilization testing: The efficiency and test-retest reliability of user operated control versus the parameter estimation (PEST) algorithm

The primary objective of this research study is to determine which form of testing, the PEST algorithm or an operator-controlled condition is most accurate and time efficient for administration of the gaze stabilization test

The test-retest reliability of the child-initiated pretend play assessment

OBJECTIVE: The purpose of this study is to establish the test–retest reliability of the Child-Initiated Pretend Play Assessment (ChIPPA) (Stagnitti, 2002a; Stagnitti, Unsworth, & Rodger, 2000).

METHOD: The first author rated 38 preschool children ages 4 and 5 years (4 with developmental delay and 34 typically developing) on the ChIPPA. The ChIPPA employs conventional play materials and unstructured play materials to assess three qualities of a child's play ability: elaborateness of play action, ability to substitute objects during play, and the child's need to imitate the modelled actions of the examiner. The ChIPPA was administered twice, at a 2-week interval, to each participant.

RESULTS: Test–retest intraclass correlation coefficients (ICCs) (Type 2,1) calculated for each of the three elaborate play measures ranged from .73 to .84. A test–retest ICC of .56 was obtained for object substitution with unstructured play materials. The test–retest ICC obtained for the combined score for unstructured and conventional play materials was .57. Percentage agreement figures ranging from 63.2% to 84.2% were obtained on test–retest of the object substitution with conventional toys and imitated actions measures. There was no significant difference between test and retest scores for these measures based on a Wilcoxon Matched Pairs Signed-Ranks Test (Wilcoxon Sign Test).

CONCLUSION: Elaborate play scores, object substitution with conventional toys score, and imitation scores on the ChIPPA showed stability over time. Object substitution scores using unstructured materials were the least stable play measures and appeared to be related to the child's play themes. Since play is the primary occupation of children, it is essential that therapists have a reliable measure of play behavior. The test–retest reliability results from the ChIPPA provide evidence that this assessment produces a stable measure of play behavior that can then guide therapists when planning intervention strategies for children.

The reliability of the 1RM strength test for untrained middle-aged individuals

The one-repetition maximum (1RM) test is considered the gold standard for assessing muscle strength in non-laboratory situations. Since most previous 1RM reliability studies have been conducted with experienced young participants, it is unclear if acceptable test–retest reliability exists for untrained middle-aged individuals. This study examined the reliability of the 1RM strength test of untrained middle-aged individuals. Fifty-three untrained males (n = 25) and females (n = 28) aged 51.2 ± 0.9 years participated in the study. Participants undertook the first 1RM test (T1) 4–8 days after a familiarisation session with the same exercises. 1RM was assessed for seven different exercises. Four to eight days after T1, participants underwent another identical 1RM test (T2). Ten weeks later, 27 participants underwent a third test (T3). Intraclass correlation coefficients (ICC), typical error as a coefficient of variation (TEcv), retest correlation, repeated measures ANOVA, Bland–Altman plots, and estimation of 95% confidence limits were used to assess reliability. A high ICC (ICC > 0.99) and high correlation (r > 0.9) were found for all exercises. TEcv ranged from 2.2 to 10.1%. No significant change was found for six of the seven exercises between T1 and T2. Leg press was slightly higher at T2 compared to T1 (1.6 ± 0.6%, p = 0.02). No significant change was found between T2 and T3 for any exercise. 1RM is a reliable method of evaluating the maximal strength in untrained middle-aged individuals. It appears that 1RM-testing protocols that include one familiarisation session and one testing session are sufficient for assessing maximal strength in this population.