Papers by Keyword: Surface Subsidence

Abstract: This paper covers design diagrams and algorithms for determining the strain state of soil mass in case of its underworking. When tunnels are constructed in restrained urban conditions peculiar to megapolises, there is an acute problem related to the assessment of their influence on the existing above-and underground facilities. The strains of buildings and structures that occur as a result of underground construction work may have an impact on the operation reliability of these facilities. Russian regulatory documents in the area of underground urban construction strictly govern the basic parameters of the subsidence trough, such as maximum vertical subsidence, curvature, inclination, etc., for most of the existing underworked structures. Such facilities include both buildings and structures of various purposes above ground and different types of utilities (roads and railways, pipelines, cable lines, etc.). The method described in the paper offers the use of an integral quantity of "volume loss" when tunneling is performed by tunnel-boring machines. The "volume loss" term shall be understood to mean the distance between tunnel lining and soil mass, which initially occurs due to the difference between rotor diameter and lining outside diameter. There are also a number of other technology factors affecting the increase of this parameter, and their quantitative assessment is given in this paper. The method proposed in this paper makes it possible to promptly assess the impact of tunneling operations on the existing underworked structures with account of basic influencing factors.

Abstract: In the process of open-pit mine stripping,the surface and slop that influenced by open-pit mining stripping, rock mass structure and lithology, blasting vibration, slope angle, groundwater and precipitation start to move and deform,which threatens the safe use of industrial and civil buildings adjacent to the open pit mining .In this paper, through the establishment of increasing the momentum of adaptive BP neural network,with the aid of existing sample data,we carried out on the network training, testing, and compared with the target, its precision is higher.The result showed that network is effective and reliable,and the trained network is applied to the observation point prediction,so we get the value of its settlement deformation in 2013.The method is expected to have the important meaning on the multi-factor coupling surface subsidence .

Abstract: A three-dimensional numerical model of the rock mass including ore body is established by FLAC3D software, and then the surface subsidence caused by backfilling under different roof thicknesses of mining stope (the vertical distance between upper mining limit and surface) are calculated and analyzed. By comparing the surface displacement, the stress distribution, and the damage zone under different conditions, the minimum roof thickness is determined.

Abstract: Through analyzing the structure of the alluvium and bedrocks, a discrimination method of main influence factors of surface subsidence was proposed, and the discrimination formula was put forward. Taking the overburden and ground surface of the large cutting height working face in Bin Chang mining region as the research object, the structure and location of key stratum and the structure of the alluvium was analyzed. Besides, through the surface monitoring, the parameters of ground movement and deformation was given, and the discrimination method was verified to be correct. Furthermore, using numerical simulation, the alluvium and bedrocks influences on the surface subsidence under different mining width were studied respectively; the ground movement and deformation characteristics under the influence of alluvium and bedrocks were put forward. The study has provided a basis for the prediction of surface subsidence under certain conditions.

Abstract: There are various applications for geothermal energy. Geothermal heating is one form of great importance. The working principle is introduced. Then the origin and development are studied. Both the advantages and disadvantages are discussed, mainly compared with traditional radiator heating. Some related issues are studied too. All in all, there is a booming prospect in markets for geothermal heating.

Abstract: Take the ground-water lowering of foundation pit project in DA Dongmen subway station in Hefei as an example, introduce a kind of environmental impact appraisal model,using softwareFLAC^3D to imitate the key index--surface subsidence, offers relevant safe bases to construct security monitoring department.

Abstract: Based on the instance of extremely thick coal seam mining under aquifer in Gonggeyingzi Coal Mine, the theoretical calculation for the height of water flowing fracture zone in this coal mine was 30.6m and calculation model was established. Analyzed by the UDEC software, the surface displacement of backfill mining was 1532mm and the height of overburden rock plastic zone was 36.5m. Compared with 135m away from coal roof to aquifer, slicing backfill mining under aquifer was confirmed to be safe and feasible based on the theoretical calculation and analysis of UDEC. The results provided the basis for the safety of extremely thick coal seam mining under aquifer in this coal mine.

Abstract: To control the surface subsidence in shield tunnel construction, a DBN-based, parameters optimization method was proposed and applied to a tunnel project in Wuhan, China. Selected the construction parameters to optimize as network nodes and set discretizing rules to determine the nodes domain, then discretized monitoring data and applied them to parameter learning to obtain complete DBN model. This model was validated with engineering measured data , then applied it to determine the setting optimal operating-range of each parameters and within that optimized the parameters real-timely according to the monitoring data changing. The results show that this model can reflect the inner link between the surface subsidence and shield construction parameters and this DBN-based method can control the surface subsidence in shield tunnel construction effectively.

Abstract: Shield construction will cause surface subsidence, and the presence of underground structures above the tunnel has an impact on surface subsidence. Based on this, with the engineering of undercross shield tunnel construction on railway station as background, used numerical simulation method to analyze the effect of surface subsidence of underground passage, and studied the influence of depth and width of underpasses on ground movement induced. The results show that: The impact of the underground passage to the wire surface subsidence caused by the shield cannot be ignored. Surface subsidence caused by double shield will be decreased because of the existence of the underground passage, and that related to the channel depth and width. The greater the depth of underground channel, the greater the surface subsidence; greater the underground channel width, the smaller surface subsidence. Meanwhile, the surface subsidence trough width and the largest settlement scope unrelated to the depth of underground tunnels but the underground channel width, and increases with the increasing of the underpass width.

Abstract: In the 202 section of subway shield Dalian interval in close proximity to existing bridge as the basis, the surface settlement and bridge pier settlement observation station are established. By the 62 day of the crossing construction monitoring, the monitoring data are analyzed in detail. When surface subsidence induced by shield tunnel construction, above the measuring point start speed is faster than settling startup speed measuring points on both sides, about 2-2.5 times, subsidence range higher about 8 to 10 m ahead of time. Away from the pier side first started, and start faster than the side near the pier ,is about 1.2 times , settlement of shield construction are mainly concentrated in the distance before and after the excavation of shield machine 10 m, accounting for 80.72%-81.6% of the total settlement . At highest risk for shield construction area, we should strengthen monitoring and make contingency plans in a timely manner.