Verification of a novel stress path method by true-triaxial test.

To verify the novel method of achieving a true-triaxial stress path with the pseudo-triaxial apparatus, a series of drained and undrained tests were carried out for the identical scheme with pseudo-triaxial apparatus and true-triaxial apparatus respectively. The differences between the two types of tests were quantified. The results show that the novel method effectively achieved the true-triaxial stress path by controlling the loading ratio of the pseudo-triaxial apparatus. The relationships of q - Îµ1 and η - Îµs measured by the two apparatuses had a higher similarity which decreases slightly with the b increase. When 0 ≤ b < 0.5, the slope of the critical state line measured by both apparatuses was almost identical. When 0.5 ≤ b ≤ 1, the slope of the critical state line measured by the novel method was slightly lower, but the biggest change was within 10% compared with the two Mohr-Coulomb criteria, the peak strength measured by the two apparatuses was distributed near the criteria, indicating the feasibility and rationality of the novel method. The tests show that the novel method greatly enriches the test range of pseudo-triaxial apparatus, which not only simplifies the process of soil 3D testing but also reduces the test cost.

Comparison of the efficacy and safety of 3 treatments for patients with osteoporotic vertebral compression fractures: A network meta-analysis.

BACKGROUND: Osteoporotic vertebral compression fractures (OVCFs) constitute an age-related health problem that affects approximately 200 million people worldwide. Currently, various treatments are performed with the goal of reducing pain, stabilizing the vertebrate, and restoring mobility. In this study, we aimed to assess the efficacy and safety of vertebroplasty (VP), kyphoplasty (KP), and conservative treatment (CT) for the treatment of OVCFs. METHODS: We performed a network meta-analysis. PubMed and Embase databases were searched to identify randomized controlled trials (RCTs) that contained at least one of the following outcomes: visual analog scale (VAS), Roland-Morris Disability Questionnaire (RDQ), European Quality of Life-5 Dimensions (EQ-5D), and new fractures. Odds ratios with 95% confidence intervals (CIs) were used to calculate the risk of new fractures, and mean differences (MDs) with 95% CIs were utilized to express RDQ, EQ-5D, and VAS outcomes. RESULTS: Sixteen RCTs with 2046 participants were included in this meta-analysis. Compared with CT, patients treated with VP had improved pain relief, daily function, and quality of life; however, no significant differences were found between VP and KP for these 3 outcomes. All treatment options were associated with comparable risk of new fractures. When the rank probability was assessed to distinguish subtle differences between the treatments, VP was the most effective treatment for pain relief, followed by KP and CT; conversely, KP was the most effective in improving daily function and quality of life and decreasing the incidence of new fractures, followed by VP and CT. CONCLUSION: VP might be the best option when pain relief is the principle aim of therapy, but KP was associated with the lowest risk of new fractures and might offer better outcomes in terms of daily function and quality of life.