Development and Application of High-Performance Grouting Materials for Anchoring Pipe in Soft Rock Tunnel

Li-xin Zhang,Jianxun Chen,Lijun Chen,Yanbin Luo,Weiwei Liu,Fangfang Dong,Hao Chen,Hao-yang Zhu 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.10

A high-performance grouting material is proposed to enhance the support effect of anchoring pipes in soft rock mass tunnels in this paper. Through mix proportion and strength tests, the initial setting time, compressive strength, and flowability of the grouting material were determined. Furthermore, based on grouting and pulling tests, the recommended parameters of the anchoringpipe were proposed. The results show that pure cement paste is an ideal grouting material for on-site application, demonstrating excellent anchoring, fluidity, high strength, and rapid hardening. Under optimal conditions of water-cement ratio at 0.46 and retarder proportion at 0.4‰, the initial settling time and the compressive strength of the grouting material are approximately 45 minutes and 28.5 MPa within 4 hours, respectively. The anchoring force of an anchoring pipe with a length of 6 m and a diameter of 76 mm can reach 448.9 kN within the same period. A field test involving anchoring pipes and pure cement paste was conducted during tunnel construction, resulting in a substantial reduction of maximum settlement and convergence of the tunnel by 57.53% and 40.48%, respectively. These results demonstrate the effectiveness

Failure Mechanisms and Modes of Tunnels in Monoclinic and Soft-Hard Interbedded Rocks: A Case Study

Jianxun Chen,Weiwei Liu,Lijun Chen,Yanbin Luo,Yao Li,Haijiang Gao,Daochuan Zhong 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.4

The issue of large deformation mechanism in soft rock tunnels has puzzled tunnel scholars for decades. Previous studies have not evolved a clear and common understanding. Therefore, detailed on-site measurement, full investigation and statistical analysis have been conducted on the instability and failure of Muzhailing Tunnel since its construction, whose length is beyond 15 km. The study aims at systematically analyzing the failure mechanisms and modes of Muzhailing Tunnel in monoclinic and soft-hard interbedded rock strata. Study results show that the angle between strata strike and tunnel axis greatly determines the magnitude of deformation, the dip direction significantly controls the bias direction and maximum deformation direction, and the dip angle deeply affects the deformation form. The failure modes of surrounding rock mainly include four types: spalling and overturning failure, bending failure, shear slip failure and buckling failure. Large deformation characteristics are summarized from six aspects: failure form, groundwater, sensitivity to influencing factors, deformation degree, deformation speed and deformation duration. The instability modes of primary lining include in-plane (transverse) instability and out-plane (longitudinal) instability. Finally, the causes of large deformation are analyzed from geological, structural, engineering and human factors.

Two new triterpenoid saponins derived from the leaves of Panax ginseng and their antiinflammatory activity

Li, Fu,Cao, Yufeng,Luo, Yanyan,Liu, Tingwu,Yan, Guilong,Chen, Liang,Ji, Lilian,Wang, Lun,Chen, Bin,Yaseen, Aftab,Khan, Ashfaq A.,Zhang, Guolin,Jiang, Yunyao,Liu, Jianxun,Wang, Gongcheng,Wang, Ming-Kui The Korean Society of Ginseng 2019 Journal of Ginseng Research Vol.43 No.4

Background: The leaves and roots of Panax ginseng are rich in ginsenosides. However, the chemical compositions of the leaves and roots of P. ginseng differ, resulting in different medicinal functions. In recent years, the aerial parts of members of the Panax genus have received great attention from natural product chemists as producers of bioactive ginsenosides. The aim of this study was the isolation and structural elucidation of novel, minor ginsenosides in the leaves of P. ginseng and evaluation of their antiinflammatory activity in vitro. Methods: Various chromatographic techniques were applied to obtain pure individual compounds, and their structures were determined by nuclear magnetic resonance and high-resolution mass spectrometry, as well as chemical methods. The antiinflammatory effect of the new compounds was evaluated on lipopolysaccharide-stimulated RAW 264.7 cells. Results and conclusions: Two novel, minor triterpenoid saponins, ginsenoside $LS_1$ (1) and 5,6-didehydroginsenoside $Rg_3$ (2), were isolated from the leaves of P. ginseng. The isolated compounds 1 and 2 were assayed for their inhibitory effect on nitric oxide production in LPS-stimulated RAW 264.7 cells, and Compound 2 showed a significant inhibitory effect with $IC_{50}$ of $37.38{\mu}M$ compared with that of NG-monomethyl-L-arginine ($IC_{50}=90.76{\mu}M$). Moreover, Compound 2 significantly decreased secretion of cytokines such as prostaglandin $E_2$ and tumor necrosis factor-${\alpha}$. In addition, Compound 2 significantly suppressed protein expression of inducible nitric oxide synthase and cyclooxygenase-2. These results suggested that Compound 2 could be used as a valuable candidate for medicinal use or functional food, and the mechanism is warranted for further exploration.

Two new triterpenoid saponins derived from the leaves of Panax ginseng and their antiinflammatory activity

Fuli Li,Yufeng Cao,Tingwu Liu,Guilong Yan,Liang Chen,Lilian Ji,Lun Wang,Bin Chen,Aftab Yaseen,Ashfaq A. Khan,Guo-Lin Zhang,Yunyao Jiang,Jianxun Liu,Gongcheng Wang,Ming-Kui Wang,Weicheng Hu 고려인삼학회 2019 Journal of Ginseng Research Vol.43 No.4

Background: The leaves and roots of Panax ginseng are rich in ginsenosides. However, the chemical compositionsof the leaves and roots of P. ginseng differ, resulting in different medicinal functions. In recent years,the aerial parts of members of the Panax genus have received great attention fromnatural product chemistsas producers of bioactive ginsenosides. The aim of this study was the isolation and structural elucidation ofnovel, minor ginsenosides in the leaves of P. ginseng and evaluation of their antiinflammatory activity in vitro. Methods: Various chromatographic techniques were applied to obtain pure individual compounds, andtheir structures were determined by nuclear magnetic resonance and high-resolution mass spectrometry,as well as chemical methods. The antiinflammatory effect of the new compounds was evaluated onlipopolysaccharide-stimulated RAW 264.7 cells. Results and conclusions: Two novel, minor triterpenoid saponins, ginsenoside LS1 (1) and 5,6-didehydroginsenoside Rg3 (2), were isolated from the leaves of P. ginseng. The isolated compounds 1and 2 were assayed for their inhibitory effect on nitric oxide production in LPS-stimulated RAW 264.7cells, and Compound 2 showed a significant inhibitory effect with IC50 of 37.38 mM compared with that ofNG-monomethyl-L-arginine (IC50 ¼ 90.76 mM). Moreover, Compound 2 significantly decreased secretionof cytokines such as prostaglandin E2 and tumor necrosis factor-a. In addition, Compound 2 significantlysuppressed protein expression of inducible nitric oxide synthase and cyclooxygenase-2. These resultssuggested that Compound 2 could be used as a valuable candidate for medicinal use or functional food,and the mechanism is warranted for further exploration.

Single-Crystalline Self-Branched Anatase Titania Nanowires for Dye-Sensitized Solar Cells

Zhenquan Li,Huang Yang,Fei Wu,Jianxun Fu,Linjun Wang,Weiguang Yang 대한금속·재료학회 2017 ELECTRONIC MATERIALS LETTERS Vol.13 No.2

The morphology of the anatase titania plays an important role in improving thephotovoltaic performance in dye-sensitized solar cells. In this work, singlecrystallineself-branched anatase TiO2 nanowires have been synthesized byhydrothermal method using TBAH and CTAB as morphology controlling agents. The obtained self-branched TiO2 nanowires dominated by a large percentage of(010) facets. The photovoltaic conversion efficiency (6.37%) of dye-sensitizedsolar cell (DSSC) based on the self-branched TiO2 nanowires shows a significantimprovement (26.6%) compared to that of P25 TiO2 (5.03%). The enhancedperformance of the self-branched TiO2 nanowires-based DSSC is due to heir largepercent of exposed (010) facets which have strong dye adsorption capacity andeffective charge transport of the self-branched 1D nanostructures.

A Novel Multiple Maneuvering Targets Tracking Algorithm with Data Association and Track Management

Shicang Zhang,Jianxun Li,Liangbin Wu 제어·로봇·시스템학회 2013 International Journal of Control, Automation, and Vol.11 No.5

A novel multiple maneuvering targets tracking algorithm with data association and track management is presented in this paper. First, the variation of the generalized pseudo-Bayesian estimator of first order is designed. Then, the data association and track management via handling two matrices are given, which reflect the relationships between target trajectory and the output of the Gaussian mixture probability hypothesis density (PHD) filter for jump Markov system models (JMS-GM-PHD) filter. The tracking performance of the proposed algorithm is compared with two conventional algorithms. One is JMS-GM-PHD filter, the other is algorithm entitled hybrid algorithms for multi-target tracking using MHT and GM-CPHD which is denoted as hybrid method hereinafter. The results of Monte Carlo simu-lation show that the proposed filter has overall performance than the conventional.

Performance of Tunnel Feet-Lock Pipe (TFP) in Sharing Vertical Foundation Load

Lijun Chen,Jianxun Chen,Yao Li,Yanbin Luo,Yongjun Mu,Taotao Hu,Chuanwu Wang 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.3

During the tunnel construction in soft ground, the insufficient bearing capacity of tunnel foundation usually causes a series of settlement problems. Tunnel feet-lock pipe (TFP) has been widely used to take the vertical load acting at the foundation of a tunnel foot. However, the detailed bearing performance of TFP is still not clear, and there is a lack of quantitative research. In this paper, a simple analytical approach is adopted to evaluate the performance of the TFP, and the main parameters affecting the supporting performance of the TFP are analyzed. The results show that the ϕ42 − ϕ140 TFP with the angle of 10° can take 3.8% −40.4% of vertical load. TFP has an effective length of 1.7 m − 2.8 m, which is related to the relative stiffness between the TFP and the stratum. With the increase of the installation angle, the TFP shares more vertical load. This trend is more obvious when the angle of the TFP is greater than 20°. If the proportion coefficient of the subgrade reaction coefficient is doubled, the vertical load shared by the TFP can be increased by 34% − 38%. For every 10 cm increase in overbreak behind the steel rib, the vertical load shared by TFP is reduced by 16%.

Adaptive Robust H∞ Sliding Mode Control for Singular Systems with Time-varying Delay and Uncertain Derivative Matrix

Qi Liu,Rongchang Li,Qingling Zhang,Jianxun Li 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.12

This paper considers the problem of sliding mode control (SMC) design for a class of nonlinear singular systems with time-varying delay and uncertainties, especially with uncertainties in the derivative matrix. By taking uncertainties of the derivative matrix into account, the state augmentation transformation is constructed such that uncertainties of the derivative matrix are eliminated. Then an appropriate integral-type sliding surface function is designed. And the resulting sliding mode dynamics is an uncertain singular time-varying delay system. A delaydependent sufficient condition which guarantees the sliding mode dynamics to be admissible with H∞ performance is established. A new version of stabilization solvability condition is then proposed in terms of linear matrix inequality (LMI), which determines the undetermined parameter K in both the sliding surface function and the SMC laws. Moreover, two distinctive controllers (i.e., an SMC law and an adaptive SMC law) are synthesized such that the finite-time reachability of the predesigned sliding surface can be ensured. Finally, simulation examples are given to demonstrate the effectiveness and the merits of the proposed theory.

THE ALGORITHM OF DYNAMIC MEMORY BASED ON RESIDUAL ANTIGENFOR INTRUSION DETECTION

Haidong Fu,Xue Li,Jianxun Chen,Xiaolong Zhang 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7

A novel dynamical memory algorithm is proposed based on residual antigen theory. The theory is used to formulate a view that the memory is dynamical. The model of multilayer defending system in Network Intrusion Detection is constructed according to the defending hierarchy of Human Immune System.The dynamical memory algorithm applied in Intrusion Detection System has been presented. Results from experiment indicated that the algorithm makes the dynamic and permanent of memory in the Intrusion Detection come true and improves the utilization of system resource.

A Novel Flame Edge Detection Algorithm via a Novel Active Contour Model

Wanli Feng,Ying Li,Shangbing Gao,Yunyang Yan,Jianxun Xue 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.9

Flame edge detection from color images is a challenging research area recently. In this paper, an extension of active contour model is proposed by adding the two information types to both internal and external energy terms. Therefore, the combination of these two forces allows for flexible initialization of the contours. This energy is then incorporated into a level set formulation with a level set regularization term that is necessary for accurate computation in the corresponding level set method. Edge extraction of different flame images using C-V model and the classical edge detection operators are compared and analyzed. Experimental results show that the existing methods do not emphasize the continuity and clarity of the flame and fire edges while the proposed method identifies the continuous and clear edges of the flame fire.