The surrounding geological conditions and supporting structures of underground engineering are often updated during construction,and these updates require repeated numerical modeling.To improve the numerical modeling ...The surrounding geological conditions and supporting structures of underground engineering are often updated during construction,and these updates require repeated numerical modeling.To improve the numerical modeling efficiency of underground engineering,a modularized and parametric modeling cloud server is developed by using Python codes.The basic framework of the cloud server is as follows:input the modeling parameters into the web platform,implement Rhino software and FLAC3D software to model and run simulations in the cloud server,and return the simulation results to the web platform.The modeling program can automatically generate instructions that can run the modeling process in Rhino based on the input modeling parameters.The main modules of the modeling program include modeling the 3D geological structures,the underground engineering structures,and the supporting structures as well as meshing the geometric models.In particular,various cross-sections of underground caverns are crafted as parametricmodules in themodeling program.Themodularized and parametric modeling program is used for a finite element simulation of the underground powerhouse of the Shuangjiangkou Hydropower Station.This complicatedmodel is rapidly generated for the simulation,and the simulation results are reasonable.Thus,this modularized and parametric modeling program is applicable for three-dimensional finite element simulations and analyses.展开更多
A reasonable evaluation of unloading deformation characteristics is of great significance for the effective analysis of deformation and stability of surrounding rocks after underground excavation.In this study,the dam...A reasonable evaluation of unloading deformation characteristics is of great significance for the effective analysis of deformation and stability of surrounding rocks after underground excavation.In this study,the damage-controlled cyclic triaxial loading tests were conducted to investigate the pore compaction mechanism and its influences on the unloading deformation behavior of red sandstone,including Young’s modulus,Poisson’s ratio,volumetric strain,and irreversible strain.The experimental results show that the increases of volumetric and irreversible strains of rocks can be attributed to the compaction mechanism,which almost dominates the entire pre-peak deformation process.The unloading deformation consists of the reversible linear and nonlinear strains,and the irreversible strain under the influence of the porous grain structure.The pre-peak Young’s modulus tends to increase and then decrease due to the influence of the unloading irreversible strain.However,it hardly changes with the increasing volumetric strain compaction under the influence of reversible nonlinear strain.Instead,the initial unloading tangent modulus is highly related to the volumetric strain,and clearly reflects the compaction state of red sandstone.Furthermore,both the reversible nonlinear and irreversible unloading deformations are independent of confining pressure.This study is beneficial for the theoretical modeling and prediction of cyclic unloading deformation behavior of red sandstone.展开更多
目的评价靶向二代测序(targeted next generation sequencing,tNGS)技术在骨关节布氏菌病病原学诊断中的应用价值。方法收集河北省胸科医院收治的108例疑似骨关节布氏菌病患者的病例资料进行研究,主要根据流行病史、临床表现、影像学表...目的评价靶向二代测序(targeted next generation sequencing,tNGS)技术在骨关节布氏菌病病原学诊断中的应用价值。方法收集河北省胸科医院收治的108例疑似骨关节布氏菌病患者的病例资料进行研究,主要根据流行病史、临床表现、影像学表现、实验室和病原学检查结果及抗布氏杆菌治疗效果进行临床综合诊断。根据最终临床诊断将患者分为骨关节布氏菌病组78例和非布氏菌病组30例。所有患者入院后均进行血清试管凝集试验(serum agglutination test,SAT)检测、采用CT导航穿刺或者手术取病灶组织样本进行细菌学培养(培养法)和tNGS检测。以最终临床诊断为参照标准,比较以上3种检测方法对骨关节布氏菌病的诊断效能。结果108例疑似骨关节布氏菌病患者中,tNGS检测骨关节布氏菌病的阳性率(60/108,55.56%)明显高于SAT检测(57/108,52.78%)和培养法(25/108,23.15%),差异有统计学意义(χ^(2)=24.982、37.934,P<0.001)。以最终临床诊断为标准,tNGS检测、SAT检测和培养法检测骨关节布氏菌病的敏感度分别为76.92%、64.10%和32.05%,特异度分别为100.00%、76.67%和100.00%,诊断符合率分别为83.35%、67.59%和50.92%,Kappa值分别为0.799、0.590和0.504。结论tNGS在骨关节布氏菌病患者的病原学诊断中具有较高的病原体检出率和敏感度,为骨关节布氏菌病患者的精准诊治提供重要参考。展开更多
基金The Construction S&T Project of the Department of Transportation of Sichuan Province(Grant No.2023A02)the National Natural Science Foundation of China(No.52109135).
文摘The surrounding geological conditions and supporting structures of underground engineering are often updated during construction,and these updates require repeated numerical modeling.To improve the numerical modeling efficiency of underground engineering,a modularized and parametric modeling cloud server is developed by using Python codes.The basic framework of the cloud server is as follows:input the modeling parameters into the web platform,implement Rhino software and FLAC3D software to model and run simulations in the cloud server,and return the simulation results to the web platform.The modeling program can automatically generate instructions that can run the modeling process in Rhino based on the input modeling parameters.The main modules of the modeling program include modeling the 3D geological structures,the underground engineering structures,and the supporting structures as well as meshing the geometric models.In particular,various cross-sections of underground caverns are crafted as parametricmodules in themodeling program.Themodularized and parametric modeling program is used for a finite element simulation of the underground powerhouse of the Shuangjiangkou Hydropower Station.This complicatedmodel is rapidly generated for the simulation,and the simulation results are reasonable.Thus,this modularized and parametric modeling program is applicable for three-dimensional finite element simulations and analyses.
基金supported by the National Natural Science Foundation of China(Grant No.52109135)the Key R&D Projects of Sichuan Province,China(Grant No.2022YFSY0007)the Postdoctoral Research Foundation of China(Grant No.2019M653402).
文摘A reasonable evaluation of unloading deformation characteristics is of great significance for the effective analysis of deformation and stability of surrounding rocks after underground excavation.In this study,the damage-controlled cyclic triaxial loading tests were conducted to investigate the pore compaction mechanism and its influences on the unloading deformation behavior of red sandstone,including Young’s modulus,Poisson’s ratio,volumetric strain,and irreversible strain.The experimental results show that the increases of volumetric and irreversible strains of rocks can be attributed to the compaction mechanism,which almost dominates the entire pre-peak deformation process.The unloading deformation consists of the reversible linear and nonlinear strains,and the irreversible strain under the influence of the porous grain structure.The pre-peak Young’s modulus tends to increase and then decrease due to the influence of the unloading irreversible strain.However,it hardly changes with the increasing volumetric strain compaction under the influence of reversible nonlinear strain.Instead,the initial unloading tangent modulus is highly related to the volumetric strain,and clearly reflects the compaction state of red sandstone.Furthermore,both the reversible nonlinear and irreversible unloading deformations are independent of confining pressure.This study is beneficial for the theoretical modeling and prediction of cyclic unloading deformation behavior of red sandstone.
基金国家自然科学基金资助项目(22072172)国家杰出青年科学基金资助项目(21825204)+2 种基金中国科学院青年创新促进会资助项目(Y2021056)榆林学院与大连清洁能源国家实验室合作基金资助项目(YLU-DNL Fund 2022007)山西省科技创新团队专项资金资助项目(202304051001007)。
