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1.
This paper examines the background, history, and results of multiple investigations associated with pyrite-based expansive soils spanning almost 40 years in conjunction with a private elementary school located in western Pennsylvania. The school was initially designed in 1960. Original construction was completed in September 1961 and the first signs of distress, which were primarily related to slab heave, were reported in early 1962. One wing of the school, a 1965 classroom addition (1965 addition) with different structural and foundation systems, did not experience any expansive soil-related damages and served as a valuable comparison throughout multiple subsequent investigations. Pyritic soil material in the subgrade in conjunction with oxygen-rich groundwater was determined to be the cause of soil movement and building distress. Expansive soil-related problems at the school continued for decades despite an investigation, civil court action, and judgment in the late 1960s followed by a remediation program in the 1970s and 1980s. Following a second round of investigations and litigation in the late 1990s, all of the original classroom, office, and gymnasium building sections, with the exception of the 1965 addition, were demolished in late 2000 and early 2001 based on safety concerns and economic evaluation. Investigation and monitoring to confirm subgrade conditions continued throughout the demolition process. As a part of this paper, the history of this case dating back to one of the early identifications of pyrite as an expansive element of concern in building construction, including one of the earliest comprehensive identifications of the complete chemical-microbiological oxidation process is presented. The initial 1960s investigation and conclusions are identified as well as the series of engineering, procedural, and construction errors that took place during and after the first remediation process that led to ongoing soil expansion and structural damage, including misguided actions and misunderstandings that complicated and delayed a final resolution in this case. Today, the industry is more familiar with the potential for pyrite-related construction problems, nevertheless, the paper incorporates lessons learned for avoiding problems and in particular, the procedural failures that led to the eventual need to abandon and demolish the school facility.  相似文献   

2.
An arousal-control and cross-over design was used to evaluate the reliability, specificity, and validity of the Normative Appetitive Picture System (NAPS), a cue exposure protocol with sets of visual alcohol, cigarette, and control cues. The authors also examined the utility of conceptualizing cue reactivity as a multidimensional phenomenon involving independent approach and avoidance dimensions. University student participants (n=369) rated multiple cue images in terms of arousing properties and capacity to elicit separate approach and avoidance inclinations. They also completed a battery of substance-related individual-difference measures. Results indicated that NAPS protocol reactivity profiles had good reliability and high specificity across cue types and individuals with different substance use histories. Avoidance reactivity independently predicted self-reports of substance-related behaviors, after controlling for approach reactivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

3.
Adults with attention deficit hyperactivity disorder (ADHD; n ?=? 104) were compared with a control group (n ?=? 64) on time estimation and reproduction tasks. Results were unaffected by ADHD subtype or gender. The ADHD group provided larger time estimations than did the control group, particularly at long intervals. This became nonsignificant after controlling for IQ. The ADHD group made shorter reproductions than the control group (15- and 60-s intervals) and greater reproduction errors (12-, 45-, 60-s durations). These differences remained after controlling for IQ and comorbid oppositional defiant disorder, depression, and anxiety. Only the level of anxiety contributed to errors (at 12-s duration) beyond the level of ADHD. Results extended findings on time perception in ADHD children to adults and ruled out comorbidity as the basis of the errors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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