RESUMEN
Soilbags are expandable three-dimensional geosynthetic bags made from high-density polyethylene or polypropylene. This study conducted a series of plate load tests to explore the bearing capacity of soft foundations reinforced by soilbags filled with solid wastes based on an onshore wind farm project in China. The effect of contained material on the bearing capacity of the soilbag-reinforced foundation was investigated during the field tests. The experimental studies indicated that soilbag reinforcement with reused solid wastes could substantially improve the bearing capacity of soft foundations under vertical loading conditions. Solid wastes like excavated soil or brick slag residues were found to be suitable as contained material, and the soilbags with plain soil mixed with brick slag had higher bearing capacity than those with pure plain soil. The earth pressure analysis indicated that stress diffusion occurred through the soilbag layers to reduce the load transferred to the underlying soft soil. The stress diffusion angle of soilbag reinforcement obtained from the tests was approximately 38°. In addition, combining soilbag reinforcement with bottom sludge permeable treatment was an effective foundation reinforcement method, which required fewer soilbag layers due to its relatively high permeability. Furthermore, soilbags are considered sustainable construction materials with advantages such as high construction efficiency, low cost, easy reclamation and environmental friendliness while making full use of local solid wastes.
RESUMEN
BACKGROUND: To determine when a bone scintigraphy investigation is appropriate in patients with newly diagnosed prostate cancer (PCa). METHODS: We retrospectively reviewed 703 newly diagnosed PCa patients who were referred for bone scintigraphy. The association between age, prostate specific antigen (PSA), Gleason score (GS) and bone scintigraphy result were investigated by series of crude or stratified analysis. RESULTS: Overall, 15.08% (106/703) patients had bone metastases. PSA and GS between positive bone scan group and negative bone scan group were significantly different, while age was not. The incidence of bone metastasis in patient with PSA < 20 ng/ml or GS < 8 was less than 10%, but increased dramatically with rising PSA and upgrading GS. In multivariate analysis, PSA ≥ 20 ng/ml (OR = 5.10, 95%CI (2.12-12.27)) and GS ≥ 8 (OR = 3.61, 95%CI (1.55-8.41)) were independently predictive of positive bone scan. CONCLUSIONS: Patients with PSA ≥ 20 ng/ml or GS ≥ 8 were in higher risk of bone metastasis, bone scintigraphy was recommended. But a bone scintigraphy is of limited value in PCa patients with PSA ≤ 20 ng/ml and GS ≤ 7.