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学者姓名：李鹏飞
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摘要 ：
There are a large number of structural planes distributed in the surrounding rock of a tunnel, and this is one of the key factors causing a tunnel's instability. Due to different geological and historical conditions, the distribution characteristics and the occurrence of structural planes in the rock mass also have significant differences. In engineering, it is common to encounter structural planes that cut across the tunnel section and have a significant impact on the stability. The occurrence of structural planes is a key factor controlling the mechanical behavior of the surrounding rock. Based on this, laboratory uniaxial compression tests were carried out by constructing a small tunnel physical model with single structural planes of different inclination angles. A related numerical simulation analysis was also carried out. This research indicates that: (1) Under the influence of a single structural plane, the dip direction with 30 degrees-60 degrees is the most dangerous situation, and when the dip angle of the structural plane is between 38 and 88 degrees, it will slip along the structural plane. (2) According to the mechanical mechanism, there are three types of cracks: tensile cracks, shear cracks, and tensile shear cracks. According to the deformation characteristics, there are four types: tension, friction, bending, and shear. (3) There is a certain correlation between the strength of a single discontinuity rock mass and that of a multi-jointed rock mass. When the dip angle of the joints' combination is 45 degrees+60 degrees, the rock mass is in its weakest state.
关键词 ：
structural planes structural planes tunnel tunnel uniaxial compression strength uniaxial compression strength anisotropy anisotropy
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| GB/T 7714 | Sun, Zhijie , Li, Pengfei , Du, Xiuli et al. Experimental Study on the Effect of Single Structural Plane on the Stability of Shallow Tunnel Surrounding Rock [J]. | APPLIED SCIENCES-BASEL , 2023 , 13 (3) . |
| MLA | Sun, Zhijie et al. "Experimental Study on the Effect of Single Structural Plane on the Stability of Shallow Tunnel Surrounding Rock" . | APPLIED SCIENCES-BASEL 13 . 3 (2023) . |
| APA | Sun, Zhijie , Li, Pengfei , Du, Xiuli , Yang, Xuanyu . Experimental Study on the Effect of Single Structural Plane on the Stability of Shallow Tunnel Surrounding Rock . | APPLIED SCIENCES-BASEL , 2023 , 13 (3) . |
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摘要 ：
This paper aims at analyzing the influence of non-associated flow rule on passive face instability for shallow shield tunnels. The influence exerted by dilation angle on the limit support pressures, the failure zones and partial failure ratios is investigated by numerical simulations. Based on the failure zone obtained from numerical simulation, a log-spiral mechanism is proposed. The upper-bound theorem is employed to acquire the limit support pressures, failure zones and partial failure ratios. The analytical results indicate that dilation angle has a significant influence on the limit support pressure and failure mechanisms. Finally, by comparison with the numerical models and existing analytical models, the results indicate that the proposed log-spiral model has a certain accuracy in analyzing the face instability of blow-out.
关键词 ：
Limit analysis Limit analysis Blow-out Blow-out Shallow tunnels Shallow tunnels Numerical simulations Numerical simulations Non-associated flow rule Non-associated flow rule
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| GB/T 7714 | Li, Pengfei , Wei, Yingjie , Zhang, Mingju et al. Influence of non-associated flow rule on passive face instability for shallow shield tunnels [J]. | TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY , 2022 , 119 . |
| MLA | Li, Pengfei et al. "Influence of non-associated flow rule on passive face instability for shallow shield tunnels" . | TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY 119 (2022) . |
| APA | Li, Pengfei , Wei, Yingjie , Zhang, Mingju , Huang, Qingfei , Wang, Fan . Influence of non-associated flow rule on passive face instability for shallow shield tunnels . | TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY , 2022 , 119 . |
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摘要 ：
A large-scale 3D combined geomechanical model test is conducted in this study to investigate the mechanical characteristics for linings of asymmetrically closely-spaced twin-tunnels constructed in sandy ground. A series of experimental results (i.e., excavation and overloading) effectively reveal the mechanical features of the linings and the stress release and displacement characteristics of the sandy ground for asymmetrical twin-tunnels during the excavation and overloading under the condition of great buried depth (vertical stress) and high stress coefficient (the ratio of lateral to vertical stress). Afterward, numerical analyses are conducted by a finite difference program FLAC3D to verify experimental results. The influences of construction sequence, stress coefficient, clear distance and lining stiffness on mechanical behaviors of linings and stratum are discussed in some details. The experimental results show that during the excavation of the asymmetrically closely-spaced twin-tunnels, the linings are in a state of compression. The lining of the smaller diameter tunnel which excavated later is susceptible to bias pressure. The bending moment located on the lateral side of the larger diameter tunnel close to the smaller diameter tunnel decrease when the smaller diameter tunnel is excavated. The change of stress release direction in the middle soil pillar is the main reason that results in the change of stress state in linings. The overloading process only causes the bending moments increasing continuously, but not affect the basic distribution patterns in linings. Numerical results indicate that if the smaller diameter tunnel is excavated first, the continuous tunneling of the larger diameter tunnel will cause sharp changes in lining moment of smaller diameter tunnel, but it will not cause serious adverse effects on the existing tunnel lining (larger diameter tunnel) if the larger diameter tunnel is excavated first.
关键词 ：
Geomechanical model test Geomechanical model test Linings Linings Middle soil pillar Middle soil pillar Numerical simulation Numerical simulation Asymmetrically closely-spaced twin-tunnels Asymmetrically closely-spaced twin-tunnels
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| GB/T 7714 | Zheng, Hebin , Li, Pengfei , Ma, Guowei et al. Experimental investigation of mechanical characteristics for linings of twins tunnels with asymmetric cross-section [J]. | TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY , 2022 , 119 . |
| MLA | Zheng, Hebin et al. "Experimental investigation of mechanical characteristics for linings of twins tunnels with asymmetric cross-section" . | TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY 119 (2022) . |
| APA | Zheng, Hebin , Li, Pengfei , Ma, Guowei , Zhang, Qianbing . Experimental investigation of mechanical characteristics for linings of twins tunnels with asymmetric cross-section . | TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY , 2022 , 119 . |
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摘要 ：
By combining model testing and numerical simulation, this paper focuses on the influence of landslides on tunnels in loess-bedrock strata by using the perfect landslide-tunnel system (LTS). A mechanical test and simulation (MTS) system was used to provide thrust for loading and unloading the trailing edge of the slope. A Particle Image Velocimetry (PIV) and 32 cluster strain gauges were adopted to monitor the deformation of the tunnel structure and landslide soil, and the sliding surface, respectively. By means of a numerical simulation, the deformation characteristics of a tunnel crossing loess-bedrock strata are comprehensively described. The influence of a cyclic load on the mechanical behavior and displacement of the tunnel and sliding surface is discussed in detail. The experimental results show that the thrust required for the first landslide is the largest, during multiple loading and unloading. With the increase in loading and unloading time, the sliding thrust gradually decreases and eventually remains stable. The landslide presents a progressive failure mode. There is a stress concentration in the upper part of the tunnel, which causes the secondary sliding phenomenon. The deformation of the sliding surface mainly occurs in the upper soil of the tunnel. The deformation direction of the tunnel is consistent with the sliding direction, and the deformation of the sliding surface mainly occurs in the soil above the tunnel. When disturbed by an external force, the tunnel deforms downward, and, when unloaded, the tunnel has a small rebound deformation. However, with the increase in loading-unloading times, the rebound deformation of the tunnel gradually decreases, and the permanent deformation gradually accumulates until the tunnel fails. The research results can provide reference for the construction and protection of tunnel engineering in loess regions, and have reference value for the control of tunnels crossing landslides.
关键词 ：
deformation characteristics deformation characteristics model test model test tunnel tunnel stick-slip stick-slip loess-bedrock landslide loess-bedrock landslide
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| GB/T 7714 | Sun, Zhijie , Yang, Xuanyu , Lu, Shuai et al. Influence of a Landslide on a Tunnel in Loess-Bedrock Ground [J]. | APPLIED SCIENCES-BASEL , 2022 , 12 (13) . |
| MLA | Sun, Zhijie et al. "Influence of a Landslide on a Tunnel in Loess-Bedrock Ground" . | APPLIED SCIENCES-BASEL 12 . 13 (2022) . |
| APA | Sun, Zhijie , Yang, Xuanyu , Lu, Shuai , Chen, Yang , Li, Pengfei . Influence of a Landslide on a Tunnel in Loess-Bedrock Ground . | APPLIED SCIENCES-BASEL , 2022 , 12 (13) . |
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摘要 ：
Carbon dots (CDs) as the advancing fluorescent carbon nanomaterial have superior potential and prospective. However, the ambiguous photoluminescence (PL) mechanism and intricate structure-function relationship become the greatest hindrances in the development and applications of CDs. Herein, red emissive CDs were synthesized in high yield from o-phenylenediamine (oPD) and catechol (CAT). The PL mechanism of the CDs is considered as the molecular state fluorophores because 5,14-dihydroquinoxalino[2,3-b] phenazine (DHQP) is separated and exhibits the same PL properties and behavior as the CDs. These include the peak position and shape of the PL emission and PL excitation and the emission dependence on pH and solvent polarity. Both of them display close PL lifetime decays. Based on these, we deduce that DHQP is the fluorophore of the red emissive CDs and the PL mechanism of CDs is similar to DHQP. During the PL emission of CDs, the electron of the molecule state can transfer to CDs. The formation process of DHQP is further confirmed by the reaction intermediates (phthalazine, dimers) and oPD. These findings provide insights into the PL mechanism of this type of CDs and may guide the further development of tunable CDs for tailored properties.
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| GB/T 7714 | Li, Pengfei , Xue, Shanshan , Sun, Lu et al. Formation and fluorescent mechanism of red emissive carbon dots from o-phenylenediamine and catechol system [J]. | LIGHT-SCIENCE & APPLICATIONS , 2022 , 11 (1) . |
| MLA | Li, Pengfei et al. "Formation and fluorescent mechanism of red emissive carbon dots from o-phenylenediamine and catechol system" . | LIGHT-SCIENCE & APPLICATIONS 11 . 1 (2022) . |
| APA | Li, Pengfei , Xue, Shanshan , Sun, Lu , Zong, Xupeng , An, Li , Qu, Dan et al. Formation and fluorescent mechanism of red emissive carbon dots from o-phenylenediamine and catechol system . | LIGHT-SCIENCE & APPLICATIONS , 2022 , 11 (1) . |
| 导入链接 | NoteExpress RIS BibTex |
摘要 ：
This paper presents a meso-scale numerical modelling method to investigate the stability of tunnels in sandy cobble stratum. Using Monte Carlo simulation, Python routine is implemented to randomly generate and filter the location information of blocks including center coordinates, sizes and orientation angles, then extract and import them into CAD modelling software in batches to mesh. The problem of overlapping detection for elliptical and ellipsoidal blocks is solved based on affine transformation, achieving higher efficiency and applicability than the existing methods. Then, using the proposed numerical modelling method, convergence-confinement analysis of circular tunnels with different cover depths is performed in plane strain condition. Meanwhile, face stability analysis of shield tunnels is carried out in three-dimensional condition. Results show that sandy cobble stratum may not be in accordance with the scale-independent soil-rock mixture. Blocks with small sizes are geotechnically significant and contribute much to the overall strength. When the cover depth ratio reaches a certain level, limit support pressure remains basically unchanged due to the strong arching effect above tunnel crown, while permissible support pressure increases approximately linearly to control deformation. Compared with the multi scale model, hardening soil model considering the overall strength is suitable for the stability analysis of tunnels in sandy cobble stratum at the macro-scale with high precision, while the macro homogeneous model ignoring the presence of blocks provides a conservative (i.e. uneconomical) prediction for the design of tunnel stability.
关键词 ：
Hardening soil model Hardening soil model Meso-scale numerical modelling Meso-scale numerical modelling Sandy cobble stratum Sandy cobble stratum Convergence-confinement method Convergence-confinement method Affine transformation Affine transformation
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| GB/T 7714 | Wang, Fan , Du, Xiuli , Li, Pengfei et al. A meso-scale numerical modelling method for the stability analysis of tunnels in sandy cobble stratum [J]. | TRANSPORTATION GEOTECHNICS , 2022 , 38 . |
| MLA | Wang, Fan et al. "A meso-scale numerical modelling method for the stability analysis of tunnels in sandy cobble stratum" . | TRANSPORTATION GEOTECHNICS 38 (2022) . |
| APA | Wang, Fan , Du, Xiuli , Li, Pengfei , Hou, Shiwei . A meso-scale numerical modelling method for the stability analysis of tunnels in sandy cobble stratum . | TRANSPORTATION GEOTECHNICS , 2022 , 38 . |
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摘要 ：
本发明公开了承压水层圆形基坑悬挂式止水帷幕涌水量解析方法，本方法应用地下水动力学原理求解出承压水层悬挂式止水帷幕圆形基坑的涌水量，引入基坑渗径影响系数，并提出其确定方法，主要实施步骤包括S1、基坑外渗流量求解；S2、基坑内渗流量求解；S3、确定基坑涌水量；本方法建立了承压水地层中悬挂式止水帷幕基坑涌水量的计算模型，采用数值模拟正反分析拟合得到了关键参数 : 渗径影响系数的计算公式，并通过大量验证工况的补充数值模拟对本方法解析解进行验证，计算结果吻合较好，表明了本方法解析模型的正确性与合理性。
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| GB/T 7714 | 孔恒 , 吴杰 , 李鹏飞 et al. 承压水层圆形基坑悬挂式止水帷幕涌水量解析方法 : CN202210194240.4[P]. | 2022-03-01 . |
| MLA | 孔恒 et al. "承压水层圆形基坑悬挂式止水帷幕涌水量解析方法" : CN202210194240.4. | 2022-03-01 . |
| APA | 孔恒 , 吴杰 , 李鹏飞 , 郭飞 , 郭彩霞 , 王凯丽 . 承压水层圆形基坑悬挂式止水帷幕涌水量解析方法 : CN202210194240.4. | 2022-03-01 . |
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摘要 ：
本发明属于基坑支护技术领域，具体的说是一种装配式组合钢管混凝土内支撑固支端结构；包括预埋钢板和短接件；所述预埋钢板的表面固定连接有托盘；所述短接件的表面固定连接有高脚螺栓；所述短接件的表面通过高脚螺栓螺纹连接有第一法兰盘；所述短接件与第一法兰盘之间装填有多个模袋；通过此结构，既能承担压力也能承载拉力和弯矩，且采用模袋混凝土灌浆填缝，可以达到内支撑两端充分填缝的效果，并消除由施工误差引起的偏心作用且实现了模块化施工，通过微型高压混凝土泵在压注过程中能够施加给混凝土一定的预应力，降低了混凝土水灰比，一定程度上提高了混凝土早期承受强度，起到快速承载作用。
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| GB/T 7714 | 郭彩霞 , 张明聚 , 单余含 et al. 一种装配式组合钢管混凝土内支撑固支端结构 : CN202211112069.4[P]. | 2022-09-13 . |
| MLA | 郭彩霞 et al. "一种装配式组合钢管混凝土内支撑固支端结构" : CN202211112069.4. | 2022-09-13 . |
| APA | 郭彩霞 , 张明聚 , 单余含 , 孔恒 , 郭飞 , 傅睿智 et al. 一种装配式组合钢管混凝土内支撑固支端结构 : CN202211112069.4. | 2022-09-13 . |
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摘要 ：
本发明公开了适用于砂卵石隧道的开挖面极限支护力计算方法，包括以下步骤：步骤1 : 假定砂卵石地层条件下，隧道开挖面失稳的破坏模式，建立理论模型，其中，隧道开挖面失稳的破坏模式由两部分组成：隧道开挖面前方的对数曲线和上方的塌落拱；步骤2 : 根据理论模型，推导理论公式，求解极限支护力；步骤3 : 对破坏区的形状进行优化，得到极限支护力的最优解。本发明提出了一种适用于砂卵石地层的盾构隧道开挖面失稳的破坏模式，利用极限分析上限法推导出了极限支护力的解析解，通过与数值模拟、典型的解析解以及模型试验对比发现。本发明提出的模型具有较高的精度，能够反映盾构隧道开挖面失稳破坏的机理。
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| GB/T 7714 | 夏俊偉 , 崔小普 , 孟凡荣 et al. 适用于砂卵石隧道的开挖面极限支护力计算方法 : CN202211374048.X[P]. | 2022-11-03 . |
| MLA | 夏俊偉 et al. "适用于砂卵石隧道的开挖面极限支护力计算方法" : CN202211374048.X. | 2022-11-03 . |
| APA | 夏俊偉 , 崔小普 , 孟凡荣 , 李鹏飞 , 李刚 , 段松 . 适用于砂卵石隧道的开挖面极限支护力计算方法 : CN202211374048.X. | 2022-11-03 . |
| 导入链接 | NoteExpress RIS BibTex |
摘要 ：
本发明公开了基于整体分析法的隧道开挖面极限支护力的计算方法，包括以下步骤：步骤1 : 基于整体分析法提出开挖面的极限支护力计算模型；步骤2 : 根据理论模型，推导出盾构开挖面极限支护力的计算公式；步骤3 : 提出盾构隧道破坏时对应的松动区模型，其中，该模型包括浅埋盾构隧道破坏模型和深埋盾构隧道破坏模型。本发明将整体分析法运用到开挖面稳定性问题中，建立了开挖面稳定性计算模型。根据隧道深浅埋，建立了考虑土拱效应的椭圆柱体‑类普式拱模型，本发明获得的极限支护力与数值模拟、已有理论结果呈现出较为一致的发展趋势，此外，本发明解析解的计算时间远小于数值模拟的计算时间，为开挖面极限支护力的设计提供了新的思路。
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| GB/T 7714 | 夏俊偉 , 崔小普 , 孟凡荣 et al. 基于整体分析法的隧道开挖面极限支护力的计算方法 : CN202211368779.3[P]. | 2022-11-03 . |
| MLA | 夏俊偉 et al. "基于整体分析法的隧道开挖面极限支护力的计算方法" : CN202211368779.3. | 2022-11-03 . |
| APA | 夏俊偉 , 崔小普 , 孟凡荣 , 李鹏飞 , 李刚 , 段松 . 基于整体分析法的隧道开挖面极限支护力的计算方法 : CN202211368779.3. | 2022-11-03 . |
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