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Qingdao, China

Wang X.,Tongji University | Li G.,Qingdao Metro Group Co. | Yuan Y.,Tongji University
Modern Tunnelling Technology | Year: 2014

Composite stratum is composed of upper soil layer and lower rock layer, of which the interface varies significantly and physical and mechanical parameters vary greatly. Aimed at pressure calculation of surrounding rock of shallow-buried tunnel in composite stratum, this paper first analyzed the characteristics of composite stratum by taking overburden thickness-span ratio and the rock thickness-span ratio as the overburden analysis indexes, then gave a double-index method with related calculation diagram and process by referring to other calculation methods based on index sensitivity analysis, and compared the calculation methods with examples. The results show that: the calculation results by double-index method are 3.6%~7.6% less than those methods of rock pillar theory, specification method and modified rock pillar theory. ©, 2015, Editorial Office of "Modern Tunnelling Technology". All right reserved. Source


Qin Y.,Beijing Jiaotong University | Yu S.,Qingdao Metro Group Co. | Zhang Y.,Beijing Institute of Graphic Communication | Jia L.,Beijing Jiaotong University | Cheng X.,Beijing Jiaotong University
International Journal of Software Engineering and Knowledge Engineering | Year: 2015

Facing the important issues of safety analysis and assessment for the train service state, an online quantified safety assessment method based on the safety region estimation and hybrid intelligence technologies was proposed in this paper. First, the previous researches on the safety analysis and assessment were briefly reviewed for the train itself and its key equipment, and the existential problems were further pointed out. Then, using the safety monitoring data and the safety region estimation theory, a new online safety assessment method with data-driven was put forward, which was followed by a detailed description of the concrete implementation steps including the EMD (Local Mean Decomposition) and EM (Energy Moment) based safety risk evaluation index selection, Interval Type 2 Fuzzy C-Means (IT2FCM) clustering based safety region boundary calculation modeling and safety risk grading. Finally, in order to verify its performance through experiments, the above method was applied in analyzing and evaluating service states of the rolling bearings, the key equipment of the train, on the basis of mass field data. The experimental results indicate that this method is valid. © 2015 World Scientific Publishing Company. Source


Li Y.,Beijing Jiaotong University | Li Y.,Qingdao Metro Group Co. | Zhang D.,Beijing Jiaotong University | Fang Q.,Beijing Jiaotong University | Wang J.,Beijing Urban Construction Design and Development Group Co.
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2015

Construction of shallow tunnel inevitably produces disturbance to upper buildings, so it's fundamental to ensure the safety of buildings in the process of tunnel construction. In this paper, we choose part of the Qingdao Line 3 Metro, from Cuo Bu Ling Station to Qingjiang Road Station, which crosses plenty of upper buildings, as research object. Herein, considering ground deformation and adopting reasonable parameters of tunneling, control measures on ground deformation and settlement of buildings are illustrated, such as pre-grouting with small duct, grouting behind primary lining, compensation grouting on settlement of building, water shutoff grouting, etc. Based on the data of on-site monitoring, settlement of building can be classified into four stages of tiny deformation, sharp increase, steady and mild increase. The maximum settlement reaches 13.84 mm, while the minimum settlement is 8.21 mm. Both of them can meet the control criteria. It's clear that research achievements here can provide technical support and safety guarantee to Qingdao Metro construction engineering. ©, 2015, Editorial Office of China Civil Engineering Journal. All right reserved. Source


Li Y.,Beijing Jiaotong University | Li Y.,Qingdao Metro Group Co. | Zhang D.,Qingdao Metro Group Co. | Fang Q.,Beijing Jiaotong University
Modern Tunnelling Technology | Year: 2015

Compared with other kinds of tunnels and underground works, the subsea tunnel has the features of high complexity, uncertainty and high risk. To ensure the successful construction of a subsea tunnel, this paper systematically analyzed the mechanism for risk occurring in the whole process of subsea tunnel construction, presented the concepts of risk accumulation and risk assessment for the whole process of subsea tunnel construction. The main risk factors were analyzed and identified in terms of subsea tunnel planning, feasibility study, prospective design, bidding and tendering, construction and operation. Based on risk analysis, appropriate risk control measures were presented and successfully applied in the Jiaozhou Bay subsea tunnel in Qingdao. ©, 2015, Editorial Office of "Modern Tunnelling Technology". All right reserved. Source


Sun F.,Qingdao Metro Group Co. | Liu T.,Ocean University of China | Lei G.,Beijing Urban Engineering Design & Research Institute Co.
Modern Tunnelling Technology | Year: 2014

ADECO-RS, i.e. "toroidal horizontal jet grouting pile + advance grouting pipe", is adopted in the Qingdao metro for the reinforcement of a water-rich sand stratum characterized by being soft at the top and hard on the bottom. The pile-forming effect and problems regarding horizontal jet grouting piles for different sand layers are studied through field sampling and observation. The impact of ADECO-RS on construction and the surrounding environment is analyzed by field monitoring and measuring. The results show that the application of ADECO-RS has an obvious positive effect on settlement control, and there are many problems, such as water leakage induced by the misalignment of two piles and ground uplift caused by improper grouting pressure control. In order to overcome these problems encountered during construction, the pile body is controlled both horizontally and vertically, and tracking monitoring is used for the grouting process. The construction results prove the applicability of ADECO-RS for use in water-rich sand strata. Source

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