目的 本研究旨在分析瘢痕子宫再次妊娠时血栓弹力图(thromboelasmography,TEG)及红细胞分布宽度变异系数(red blood cell distribution width coefficient of variation,RDW-CV)、中性粒细胞/淋巴细胞比值(neutrophil to lymphocyte rat...目的 本研究旨在分析瘢痕子宫再次妊娠时血栓弹力图(thromboelasmography,TEG)及红细胞分布宽度变异系数(red blood cell distribution width coefficient of variation,RDW-CV)、中性粒细胞/淋巴细胞比值(neutrophil to lymphocyte ratio,NLR)、单核细胞/淋巴细胞比值(monocyte lymphocyte ratio,MLR)以及全身免疫炎症指数(systemic immune-inflammation index,SII)等指标的变化情况,探讨凝血相关指标及炎症相关指标对瘢痕子宫再次妊娠风险预测价值。方法 回顾2021年3月1日至2024年3月1日在延安市人民医院产科住院的孕妇临床资料168例。比较瘢痕子宫不同妊娠阶段TEG及RDW-CV、NLR、MLR、SII等炎症指标的变化;比较瘢痕子宫孕妇与健康孕妇TEG及RDW-CV、NLR、MLR、SII等炎症指标的变化情况。结果 瘢痕子宫孕妇中,与中孕组相比,晚孕组孕妇TEG中的R值增加,Angle角、MA值减少(均P<0.05);NLR、MLR增高(P<0.05)。瘢痕子宫孕妇与健康孕妇相比,瘢痕子宫TEG中的R值、K值、Angle角、MA值的差异无统计学意义(均P>0.05);NLR、MLR差异有统计学意义(P<0.05)。结论 瘢痕子宫再次妊娠对TEG及部分炎症指标有影响,随着孕周数增加TEG指标与炎症指标有所变化;TEG及炎症指标联合检测可对瘢痕子宫再次妊娠风险作出预测。展开更多
The stability of strip footings subjected to eccentrically inclined loads is critical for reliable foundation design.This study investigates the effect of a circular unlined tunnel in a rock mass on the ultimate beari...The stability of strip footings subjected to eccentrically inclined loads is critical for reliable foundation design.This study investigates the effect of a circular unlined tunnel in a rock mass on the ultimate bearing capacity(UBC)of a foundation with width B under inclined and eccentric loads.Adaptive finite element limit analysis was employed to evaluate the reduction in UBC of the footing resting above a tunnel.The examined critical parameters include normalized load eccentricity(e/B),load inclination(β),and horizontal and vertical distances of the tunnel from the foundation(P/B and Q/B,respectively),along with rock mass properties.The results reveal that for e/B≥0.25 and β≤60°,the reduction coefficient,R_(c)≥0.90,suggesting that the presence of a tunnel has a minimal impact on the load-bearing capacity of the footing,with failure primarily governed by load eccentricity and inclination.Additionally,potential failure mechanisms are explored,showing that at lower e/B,higher β,and lower Q/B,the tunnel significantly affects footing's failure envelope.Conversely,at higher e/B and lower β,failure is due to rotational effects of footing,regardless of the tunnel's position.To predict the Rc more accurately,due to the time-consuming nature of direct calculations,both MLR and ANN models were developed.The MLR model provided a baseline for comparison,while the ANN model,with a coefficient of determination(R2)of 0.98,demonstrated superior accuracy compared to the R2=0.96 of MLR.Using both approaches ensured robust and efficient predictions of Rc.Since Rc does not directly provide the reduced UBC of footing due to presence of tunnel,the study introduced bearing capacity factor(Nc)to enable direct calculation of the reduced UBC of footing.These findings offer theoretical guidelines for preliminary design and provide practitioners with an effective tool for evaluating UBC reduction in complex loading scenarios involving tunnels.展开更多
基金supported by the Civil Engineering Department, Madan Mohan Malaviya University of Technology, Gorakhpur, India
文摘The stability of strip footings subjected to eccentrically inclined loads is critical for reliable foundation design.This study investigates the effect of a circular unlined tunnel in a rock mass on the ultimate bearing capacity(UBC)of a foundation with width B under inclined and eccentric loads.Adaptive finite element limit analysis was employed to evaluate the reduction in UBC of the footing resting above a tunnel.The examined critical parameters include normalized load eccentricity(e/B),load inclination(β),and horizontal and vertical distances of the tunnel from the foundation(P/B and Q/B,respectively),along with rock mass properties.The results reveal that for e/B≥0.25 and β≤60°,the reduction coefficient,R_(c)≥0.90,suggesting that the presence of a tunnel has a minimal impact on the load-bearing capacity of the footing,with failure primarily governed by load eccentricity and inclination.Additionally,potential failure mechanisms are explored,showing that at lower e/B,higher β,and lower Q/B,the tunnel significantly affects footing's failure envelope.Conversely,at higher e/B and lower β,failure is due to rotational effects of footing,regardless of the tunnel's position.To predict the Rc more accurately,due to the time-consuming nature of direct calculations,both MLR and ANN models were developed.The MLR model provided a baseline for comparison,while the ANN model,with a coefficient of determination(R2)of 0.98,demonstrated superior accuracy compared to the R2=0.96 of MLR.Using both approaches ensured robust and efficient predictions of Rc.Since Rc does not directly provide the reduced UBC of footing due to presence of tunnel,the study introduced bearing capacity factor(Nc)to enable direct calculation of the reduced UBC of footing.These findings offer theoretical guidelines for preliminary design and provide practitioners with an effective tool for evaluating UBC reduction in complex loading scenarios involving tunnels.
