Behavior of bladder-type inflatable anchors in sand: Physical modeling.

This paper describes an investigation into the performance and pull-out capacity of a bladder-type inflatable anchor. The inflatable anchor is a type of support member used in foundation pit support engineering. Based on improvements and innovations, the multi-bladder-type inflatable anchor consists of two or more hydraulically inflated rubber membranes that are embedded in unconsolidated earth and then inflated to provide pull-out capacity. The primary objective of this study was to investigate the impact of inflation pressure, embedment depth, number of bladders, bladder length, and rubber film thickness on the pull-out capacity and displacement of the inflatable anchor. The tests were carried out in a cylindrical steel test chamber filled with medium coarse sand. The pull-out behavior of the bladder-type inflatable anchor and the five variables was investigated, and the benchmark values for all tests are determined by similarity ratio. Compared with the single bladder inflatable anchor, under the same conditions, the ultimate pull-out capacity of the two bladder-type inflatable anchor is 1.2 times higher, with ultimate displacement only 37.5% of the former, the ultimate pull-out capacity of the three bladder-type inflatable anchor is 1.7 times higher, with ultimate displacement only 32.3% of the former. The two bladder-type inflatable anchor is superior to the single bladder inflatable anchor and the multi-bladder-type has higher ultimate pull-out capacity and greater stiffness. The inflation pressure and the rubber film thickness have a significant influence on the bearing capacity. The number of bladders effectively controls the ultimate displacement.

Clinical analysis of risk factors for neonatal clavicular fracture / 中国基层医药

Objective To investigate risk factors for neonatal clavicular fracture,to provide a reference for clinical treatment.Methods A retrospective analysis was performed towards 3 025 live births,47 cases had neonatal clavicular fracture.The birth weight,mode of delivery,maternal age,parity,gestational age,clavicle second stage of labor,the fundus height plus abdominal circumference,cord around neck,and other fracture potential risk factors were analyzed through univariate and multivariate analysis,and the risk factors were summarized.Results 3 025 cases of live births,of which 47 cases had neonatal clavicular fracture,clavicle fracture rate was 1.55%;univariate results sug-gested that the mode of delivery,birth weight,the second stage of labor,maternal age,gestational age,nuchal cord,ma-ternal weight's clinical data index had statistically significant differences between the fracture group and non -fracture group (χ2 =37.514,34.997,28.647,19.847,18.847,16.694,all P <0.05 );multivariate analysis showed that mode of delivery,birth weight,the second stage of labor,gestational age,nuchal cord,maternal body mass index were a newborn children collarbone fracture independent risk factors.Conclusion Mode of delivery,birth weight,the second stage of labor,gestational age,nuchal cord,maternal body mass index are independent risk factors for neonatal clavicu-lar fracture,obstetric should continue to improve midwifery skills,to develop prevention strategies to reduce the inci-dence of neonatal clavicular fracture.