Applied Mechanics and Materials Vols. 438-439

Abstract: Twin tubes complementary ventilation technology was applied in Dabieshan highway tunnel for the first time in domestic. Based on test of the amount of carbon monoxide, smoke concentration and wind velocity, and analysis of the data, it is concluded that the twin tubes complementary ventilation technology is workable and reliable. In addition, the results provide the reference for the ventilation monitoring of Dabieshan tunnel and also for the technical guidance of ventilation mode in the later similar engineering design.

Abstract: On the basis of current situations of urban underground transportation junctions and combining with on-site investigation of Beijing Xizhimen transportation junction station, this paper puts forward the disaster-prevention index system of urban underground transportation junctions. Specific analysis is on the disaster index in four aspects: informational sign, fire-fighting equipment, evacuation capability and refuge. 17 indexes are extracted reflecting the disaster evacuation performance, the weights of each disaster-prevention index are defined by Analytic Hierarchy Process (AHP), and fuzzy comprehensive evaluation method is adopted to conduct comprehensive evaluation of safety performance. The established disaster-prevention index system has practical value and significance to improve the disaster-prevention capability of urban underground transportation junctions.

Abstract: As the rapid growth of national economy and further development of city construction, the exploitation of high-rise buildings and underground buildings is augmenting gradually, and leading to more and more deep foundation excavation that embrace difficult design, complicated construction technology, vulnerability to circumstance and other complex characteristics. A lot of accidents happen to deep foundation excavation in China every year, which severely affected our daily life and brought great losses to the corporations. Therefore, it is necessary to carry out effective risk management on the deep foundation excavation based on on-site surveys. This paper ascertains the main risks by the way of RBS, and with the help of adjudication by the experts and AHP methods, calculates the weights and makes sequence, then determines different corresponding risks followed by strategies put forward, so as to lay foundation for risk management in the construction corporation to effectively reduce the risk possibility and losses.

Abstract: Undercutting method is now adopted in prosperous cities or complex areas with all kinds of surroundings, but this method has great risks. Undercutting method includes many ways, it is important to choose a rational one in one certain project. Based on the design and the construction, this paper analyzes the CRD method, the PBA method, the Middle Hole Construction method and the Double Side Drift method which were widely used in China. The paper takes the safety, the cost and the construction time into account, using Comprehensive Evaluation and Fuzzy Mathematics to make sure that the chosen construction method is the most feasible one. Through analysis we could ensure that the construction of the Metro engineering is safe, economic and quick.

Abstract: This paper identifies and grades the major risk sources in the Center Street Subway Station in Shenyang, by adopting the Fuzzy Theory to make identification and gradation of risk sources in subway station construction with hole-pile method. By the analytic hierarchy process, it computes the weight and membership of every risk source during the construction process, establishes the evaluation model for identification and gradation of risk sources in hole-pile construction of subway station, obtaines the weights and indictors during the overall construction process of the Center Street Subway Station in Shenyang, and finally determines the danger level in subway station construction under the maximum membership principle. The research gives a reference for hole-pile construction of subway station.

Abstract: The paper introduces some information about Harbin Metro line 1, makes the decision analysis on economies, environment, society and geological environment of Harbin Metro line 1 by some fuzzy comprehensive evaluation model, and gives the weight coefficients of indicators through analytic hierarchy process. The comprehensive evaluation result provides the basis for decision-makers during decision of metro projects.

Abstract: Harbin metro, the first engineering is in the process of being built. Metro tunnel is supported by reinforced concrete structure. Commonly used model is used in design of shield tunnel liner. In this paper, the habitual model is improved. The joint of model of the habitual model is improved and the endogenetic force formulas for the new model are derived. At last, the derived formulas and the existing formulas are validated by Harbin first metro. According to the research result, we can know the formulas derived in the paper are credible and they have academic practical meaning for design and construction of the subway liner.

Abstract: This paper proposes the index set of safety management of shield metro construction, then realizes the PCA dimension of the 24 indexes in the set. By integrating and restructuring the 9 principal component which we got as the SPSS operate result, the Index System of safety management of shield metro construction is built up. Combined with FUZZY theory, the safety management model of shield metro construction is established. Finally, combined the practical engineering, this paper analyzes the result of safety management, and gives the improvement suggestion against the shield metro construction.

Abstract: In the construction of high-rise buildings, the effect produced by the excavation of deep and large foundition pits on the surrounding structures cannot be ignored. This paper presents a case study from a construction project located in Nanjing, in which the dynamic excavation process of a founditon pits is numerically analyzed with finite element method on Plaxis. The impact of various excavation stage on subway tunnel nearby is achieved in terms of the results of data analyses and assessments.

Abstract: Two subway stations of line Z1 were built in Tianjin cultural center and Tianjin Yujiapu traffic hub. The diaphragm wall depth of the two stations was more than 60 m. The geological and hydraulic conditions were different in the two site. Keeping stability of slot wall was the key of supper-deep diaphragm wall construction to the both stations. Two 3D numerical models were built by ABQUS software to simulate the grooving process. The conditions of different slurry specific gravity and grooving depth were calculated. The deformation laws of the slot wall and ground settlement around the slot wall were studied. The results showed the upper soft silty clay and deeper silty sand layers were easy collapse. Finally, some technologies such as "] [" type guide wall, properly improving slurry specific gravity, soil cement mixing reinforcement were suggested to improve the stability during the diaphragm wall construction of the two stations.