Causes of post-installation penetration of jack-up spudcan foundations in clays.

This paper examines possible causes of additional spudcan settlement after preloading using both centrifuge model tests and small strain finite element analysis, in which spudcan settlement due to cavity collapse, consolidation settlement and settlement due to cyclic loading are incorporated. Back-analyses of seven jack-up rigs in the Gulf of Mexico show that even complete cavity collapse could only explain part of the measured additional settlements in the majority of the cases. Small strain finite element analyses also show that spudcan consolidation settlement is likely to account for even less of the additional settlement than cavity collapse in the sites considered. On the other hand, centrifuge model tests show that large amplitude cyclic rocking has a very significant effect on spudcan settlement, even if half of the preload has been removed. However, this effect cannot be explained by the exceedance of the yield envelope since the loading combination had not exceeded the yield envelope. One possible explanation is the stiffness and strength degradation of the soil under cyclic loading. In view of this, a conservative approach is recommended in instances where large amplitude cyclic rocking, such as that arising from storm loading, is expected shortly after preloading. The presence of lattice legs is found to reduce the spudcan settlement during large amplitude cyclic rocking.

Effects of xuebijing on nitric oxide and VEGF-A in exhaled breath condensate of patients with ALI/ARDS / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the clinical significance of changes of nitric oxide (NO) and vascular endothelial growth factor A (VEGF-A) in exhaled breath condensate (EBC) of patients with acute lung injury/acute respiratory distress syndrome (ALI/ARDS) after they were treated by Xuebijing (XBJ), and to evaluate the effect of the EBC detection technology.</p><p><b>METHODS</b>Totally 32 ALI/ARDS patients receiving mechanical ventilation at intensive care unit (ICU) were randomly assigned to the treatment group and the control group, 16 cases in each group. Patients in the control group were treated by routine therapy, while those in the treatment group were treated by routine therapy + XBJ. The therapeutic course for all was 5 days. The EBC sample was collected by improved EcoScreen condenser within 24 h after confirmed diagnosis of ALI/ARDS and on the fifth day of medication. The levels of NO and VEGF-A were measured by EIA in EBC and serum. The changes of NO and VEGF-A in EBC were observed before and after treatment.</p><p><b>RESULTS</b>Compared with before treatment, the level of NO in EBC and serum decreased and VEGF-A increased after treatment, showing statistical difference (P < 0.05, P < 0.01). After treatment the level of NO in EBC and serum was lower in the treatment group than in the control group (P < 0.05). The VEGF-A in EBC was higher in the treatment group than in the control group (P < 0.05). There was no statistical difference in the serum VEGF-A level between the two groups (P > 0.05).</p><p><b>CONCLUSIONS</b>XBJ was an effective therapeutic drug capable to control the in vivo inflammation reaction in patients with ALI/ARDS. The detection of changes of VEGF-A and NO levels by EBC could judge the inflammatory reaction degree in ALI/ARDS patients, and help evaluating the therapeutic effect.</p>