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61.
在施工中要采取有效的措施来预防塌方的发生,当在施工中不可避免地出现塌方的时候,能够提出合理的处理方法和步骤。介绍了隧道工程预防塌方的施工措施及隧道发生塌方后的处理方法。 相似文献
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大跨隧道双侧壁导坑法施工力学行为研究 总被引:1,自引:0,他引:1
结合某城市道路,对大跨隧道双侧壁导坑法施工进行了弹塑性数值模拟,探明了施工过程中国岩深部位移、围岩稳定性,以及衬砌结构的受力特性.研究表明,围岩等级较高,围岩条件差的情况下,采用双侧壁导坑法在技术上是可行的,并且能够很好的控制施工过程中围岩的稳定. 相似文献
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In 2013, the concept of the ‘Silk Road Economic Belt and the 21st-Century Maritime Silk Road (Belt and Road)’ was initiated by the Chinese government, which involves Asian, European and African continents and their adjacent seas. Logistics plays a core role in such a large framework of economy and trade. In recent years, China, European Union, and Southeast Asia pay much attention to the design and development of the intermodal transportation network towards both economic and environmental efficiency. In this paper, we propose an empty container repositioning model in the intermodal transportation network of Belt and Road (B&R) Initiative by considering both standard and foldable containers. In this model, empty containers are repositioned from the inland of the original area, such as China, to other areas of B&R Initiative related countries and regions, such as European Union and Southeast Asia. We develop a mixed integer linear programming model to determine the optimal repositioning of empty containers via the intermodal transportation network. An Artificial Bee Colony algorithm is developed to solve large size problems in practice and numerical experiments are conducted to show the efficiency of our proposed algorithm. We provide managerial insights regarding the impact on the network performance of foldable containers transportation. 相似文献
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Yui-yip Lau Ka-chai Tam Adolf K. Y. Ng Zhang Jing Jiejian Feng 《Maritime Policy and Management》2018,45(3):403-417
China’s Belt and Road (BR) initiative is expected to facilitate international trade between the countries involved. In this study, we review the special requirements of wine logistics and the market growth potential of wine consumption in China. A model minimizing generalized logistical costs is developed and applied to wine imports in China, so that the best candidate cities in which to locate transport gateways and distribution centers can be identified. Our analysis suggests that the most preferred gateways are Shanghai, Tianjin, Guangzhou, and Hong Kong, which all have similar delivery costs. In comparison, Beijing and Chongqing have much higher delivery costs, mainly because they do not have good access to marine transport and/or efficient domestic distribution networks. For long-distance intercontinental transport of large volumes of wine, marine shipping remains the only viable delivery mode. However, wine distribution within China extensively uses air, road, and water transport. Therefore, cities with excellent multi-modal transport services are better positioned to become wine logistics gateways. Our study also highlights the importance of value-added services and good government support, which are important factors that influence distribution costs and quality. 相似文献
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Water bursts during tunnel construction endanger construction, and it is therefore necessary to reserve a waterproof dike with the required thickness to avoid water bursts and to take reinforcement of the dike and treatment of the structure liable to trigger a water burst. Using the water burst at K5+398 of the Mingyueshan tunnel of the Shanghai-Chengdu expressway as an example, and considering the type of tunnel section and the upright mudstone of the dike, the waterproof dike at the work face is simplified as a round thin plate. A formula for the calculation of a minimum safety thickness for the critical waterproof dike is deduced by analyzing the force applied on the water-proof dike, and the minimum safety thickness for the water burst section at K5+398 of the Mingyueshan tunnel is cal-culated. The numerical simulation analysis demonstrates the critical thickness of waterproof dike at K5+398 of the Mingyueshan tunnel is 1.4-1.55 m, and the calculated water inflow and water burst basically agree with the actual condition. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved. 相似文献
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Combining the present situation and development trend of different tunnel support technologies at home and abroad, this paper analyzes the problems of rockburst in hard rock tunnels and large deformation in soft rock tunnels caused by high ground stress. It is concluded that: 1) regarding the rockburst problem, the current support technology is mainly influenced by the rock burst mechanism which is dominated by static factors, and so the used support components are generally of smaller deformation performance and "passive support" properties; 2) as the rockburst is the result of dynamic-static stress coupling, and only the anchor bolt has the "active support" attribute in the current "shotcrete+anchor bolt+wire net" support system, so the best support system should have the two functions of active support and energy release in terms of the rockburst problem, and the key focus of the research and development is anchorage members; 3) there are three main support types for large deformation in soft rock tunnels, e.g. the heavy support, layered support and yielding support. Among them, the heavy support system in underground cavern with large deformation is easy to induce excessive surrounding rock pressure, and so the applicable conditions are limited. The layered support system is still not the best choice due to its immature theoretical study, difficult determination of the thickness value and the installation time of each support layer and the interference to construction progress. With the characteristics of timely support and yielding while supporting, the yielding support system can give full play to the performance values of surrounding rocks and supporting materials, and make both of them reach the optimal state, so it is the best choice for supporting the soft rock tunnels with large deformations. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved. 相似文献