Advanced Materials Research Vols. 261-263

Abstract: Construction of a real estate project is close to one side of the metro station which has finished main structure building. The diagram of the metro station is used as supporting during the excavation of the pit of the real estate project, which will result in the one side unloading of the metro station. Bearing the unbalanced soil pressure, the metro station will have additional deformation and internal force. During the pit design, the additional deformation and internal force is analyzed for every step of the excavation. And the additional force is superimposed with the original force of the metro station to calculate the final internal force of the metro station. By adjusting the design parameters of the pit, the safety of the metro station is evaluated.

Abstract: Firstly several seismic simplified methods commonly used for deep circular tunnel are evaluated and the difficulties in response displacement method are pointed out. Then the analytical solution of soil spring coefficient and soil response of deep circular tunnel is derived from using complex variable theory of planar elastic theory based on pseudo-static hypothesis. The analytical solution has been verified by comparing its predictions with results from an analysis in finite element method. It is concluded that the analytical solution can be regarded as one feasible reference for the simplification of response displacement method.

Abstract: It is very important to study the structure effect of cavity group for controlling disasters in engineering and coordinating mining of the hidden danger resources. The cavity group structure was defined and classified. The structure effect of the twelve kinds of working conditions were simulated by using Rock Failure Process Analysis code (RFPA^2D). the results show as follows: 1) The stability order of the typical cavity group structures was the second one, the third one and the first one; 2) The phenomena of small cavities interpenetrating and forming a big cavity often appeared in the kinds of the first and the third structure in the process of system catastrophe, but not in second structure; 3) The system appeared catastrophe easily with the number rising of the first structure, the third structure taking the second place and the second structure taking the last place; 4)The risk of the system consisting of two groups of the third structures was greater than one of the system consisting of one group of the first structure; 5) he more the number of the poor stability structures was in the up of system, the more poor stability the system had; 6) The same structures were placed in the upper and lower order in system, the lower structure would appear prior into the failure and instability status.

Abstract: Steel-tube bored grouting anti-sliding retaining wall is a kind of technique combined with grouting and micropiles, treated as the retaining wall in mechanics analyzing. It is the significant feature that steel-tube bored grouting anti-sliding retaining wall change the partial sliding mass to anti-sliding mass. Taking the case of landslide located in south K108 of Guangdong segment of Beijing-Zhuhai highway, the landslide is reinforced by steel-tube bored grouting anti-sliding retaining wall and discharged groundwater from sliding mass. The K108 landslide is in the situation of stability by means of displacement analysis on monitoring bores and stability computation. The result of treatment show that the steel-tube bored grouting anti-sliding retaining wall is an effective method on treating landslide.

Abstract: Huangdao water sealed underground oil tank, which lies in Qingdao, Shandong province, is one of strategic reservoir of oil in China. Targeting at a real pragmatic problem that sometimes the rock mass integrity index is more than 1 and taking Huangdao water sealed underground oil tank as an example, the rock sample wave velocity-stress relation tests are carried out. Then unloading index is put forward and formula of raock integrity index is modified so as to improve rock quality classification method. In the end, the improved rock quality classification method is applied to Huangdao water sealed underground oil tank engineering. The result shows that the quality of most rock masses here is level I or II.

Abstract: Based on the underground Hongtudi station of Chongqing Rail Transit Line VI, stress and plastic strain of surrounding rock, internal forces of supporting structure and vault settlement are calculated in different widths of core pillar. Comprehensive analyses indicate that there is an optimal value of core pillar width in the construction of tunnel with the double-side heading method. Width of core pillar, 0.3 times as large as the tunnel span, is suggested in other projects with the same construction method, which is of great significance in practices.

Abstract: Concrete is used in bridge as structural material in a great measure. Problem about durability of concrete was fully realized with the passage of time and accumulation of experience. An effective way of improving the durability of pile concrete was obtained in this paper according to researching and analyzing the durability of concrete used in bored pile of TangWa Bridge in freeway between LuoYang and LuanChuan.

Abstract: After the rock bolt or cable bolt installed in rock and soil mass, as the time goes on, the pre-stress load in bolt maybe losing. Through studying and analyzing the field test data, the factors leading to pre-stress losing are both external and internal factors. The internal factors are cable steel wire loose and rock and soil mass creep deformation. In which the cable steel wire has been pre-tensioned, its affection for load losing is very little. While the rock and soil mass creep deformations have great affection to pre-stress loss. There, if the cable bolt is installed in hard rock, the rock creep deformation will be very little and the load losing in cable bolt will be very few. But if the cable bolt is installed in soft rock and soil mass, the creep deformation will be very much greater than in hard rock, and the pre-stress losing in cable bolt will be very great. The external factors are shocking load, such as blasting load, storm rainfall, temperature change and stress change of anchored rock mass. Through analyzing these affecting factors, some recommend the compensative measures which include choosing appropriate steel wire, pre-tensioning and over-tensioning cable bolt, controlling the blasting rigorous and monitoring the cable long time enough in work time.

Abstract: Generally, the slope stability anchoring force is calculated by using vertical slice methods. A more feasible algebraic expression for the calculation of slope stability anchoring force is presented herein, which is obtained from the force limit equilibrium conditions of inclined slices based on the concept of the inclined slice method. The examples described herein show that the results from the calculation of the anchor force by using this method are similar to those by using conventional methods such as Swedish slice method and simplified Bishop method if the slope stability and safety factor are given. In addition, calculation of the anchoring force is simplified by using this method with accurate results, making it significantly easy for engineers and technicians to familiarize with and apply.