scholarly journals Calculation of the Vertical Strata Load of Utility Tunnel Crossing Ground Fissure Zone

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Dan Zhang ◽  
Zhiping Hu ◽  
Ganggang Lu ◽  
Rui Wang ◽  
Xiang Ren
Keyword(s):  
Soil Layer ◽  
Earth Pressure ◽  
Reference Value ◽  
Additional Stress ◽  
Fissure Zone ◽  
Engineering Structures ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Utility Tunnel ◽  
Surrounding Soil

A ground fissure is a geological disaster in which the vertical dislocation of strata causes surface rupture. Ground fissures can cause extreme harm to the surface and underground buildings. Ground fissure activity can result in different settlement on the two sides of the strata, which will generate additional stress (pressure) that differs from the stress of the general stratum on underground structures across the ground fissure zone. It is essential to assess the effective stress of strata in the design of underground engineering structures across a ground fissure zone. The Xi’an ground fissure through a utility tunnel was focus of the research, and a physical model and data for oblique crossing of the 45° ground fissure were analyzed. A model of the utility tunnel structure was established, including the surrounding soil load as an active ground fissure environment. This model was used to calculate the vertical formation pressure of the overlying soil on the utility tunnel. A method to calculate the overlying load on the utility tunnel caused by ground fissure activity was proposed and compared with the calculation based on the A. Marston principle. The results showed that the ground fissure load calculation method based on the strata-holding effect can effectively calculate the earth pressure of the surrounding soil layer of the utility tunnel in the cross-ground fissure section. The results of this work provide guidance and reference value for the design of a utility tunnel in an area with the potential for a ground fissure.

scholarly journals Experimental Study on Deformation Mechanism of a Utility Tunnel in a Ground Fissure Area

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Dan Zhang ◽  
Zhiping Hu ◽  
Ganggang Lu ◽  
Rui Wang ◽  
Xiang Ren
Keyword(s):  
Deformation Mechanism ◽  
Physical Simulation ◽  
Hanging Wall ◽  
Earth Pressure ◽  
Structural Deformation ◽  
Physical Model Test ◽  
Ground Fissures ◽  
The Earth ◽  
Utility Tunnel ◽  
Relationship Of

This paper discusses the deformation mechanism of a utility tunnel crossing active ground fissures in Xi’an as observed in a physical model test. The purpose of this work is to confirm the precise effects of ground fissures on utility tunnels. The physical simulation experiment is carried out to measure the earth pressure and the strain relationship of the structure and the structural displacement. The structure appears to have been destroyed by torsion. The structural deformation located in the tunnel’s footwall was more serious than that in the hanging wall. However, at the top of the utility tunnel structure, the earth pressure in the footwall was less than that in the hanging wall. The increased range of the hanging wall at 0.3–1.5 m (the prototype within the range of 22.5 m) and decreased range of the footwall at 0.3–0.8 m (the prototype within the range of 12 m) were basically consistent with changes in the contact pressure at the structure’s bottom. This was roughly consistent with the main deformation zone of ground fissures mentioned in the specification, with the hanging wall at 0–20 m and footwall at 0–12 mm. Displacement meter data shows that the structure tends to deform to the lower right as the utility tunnel is “twisted” clockwise. These observations mark a notable departure from the previously published failure mode of metro tunnels under active ground fissures.

Failure Models of Buildings Affected by Xi’an Ground Fissure

2010 ◽  
Vol 168-170 ◽  
pp. 1513-1517
Author(s):  
Wen Yang Li ◽  
Chun Juan Pan ◽  
Yu Ming Men
Keyword(s):  
Building Materials ◽  
Soil Layer ◽  
Normal Fault ◽  
Stone Masonry ◽  
Deformation Characteristics ◽  
Horizontal Deformation ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Failure Models ◽  
Xi’An City

Based on surveys of buildings passing through ground fissures, failure and deformation characteristics of buildings are analyzed. Failure models of buildings under the influence of Xi’an ground fissures are proposed. By means of the simulations on PLASIX, taking for the f6 of ground fissures in Xi’an city, the variations of stress field and displacement field of the overlying soil layer which the normal fault qualitative ground fissures lead to are studied. It separately calculated out of the variation of the features of deformation, when brick masonry, block masonry and stone masonry act as solely material of the building. The total, vertical and horizontal deformation of buildings built of stone masonry are the largest and brick masonry’s deformations are the smallest. It is suggested that materials with small gravity density should be used for building materials.

scholarly journals Method of Calculating the Compensation for Rectifying the Horizontal Displacement of Existing Tunnels by Grouting

2020 ◽  
Vol 11 (1) ◽  
pp. 40
Author(s):  
Yongjie Qi ◽  
Gang Wei ◽  
Feifan Feng ◽  
Jiaxuan Zhu
Keyword(s):  
Volume Expansion ◽  
Soil Layer ◽  
Horizontal Displacement ◽  
Soil Mass ◽  
Calculation Model ◽  
Additional Stress ◽  
Corrective Effect ◽  
Engineering Data ◽  
Subway Tunnels ◽  
Good Agreement

Sleeve valve pipe grouting, an effective method for reinforcing soil layers, is often employed to correct the deformation of subway tunnels. In order to study the effect of grouting on rectifying the displacement of existing tunnels, this paper proposes a mechanical model of the volume expansion of sleeve valve pipe grouting taking into consideration the volume expansion of the grouted soil mass. A formula for the additional stress on the soil layer caused by grouting was derived based on the principle of the mirror method. In addition, a formula for the horizontal displacement of a tunnel caused by grouting was developed through a calculation model of shearing dislocation and rigid body rotation. The results of the calculation method proposed herein were in good agreement with actual engineering data. In summary, enlarging the grouting volume within a reasonable range can effectively enhance the grouting corrective effect. Further, with an increase in the grouting distance, the influence of grouting gradually lessens. At a constant grouting length, setting the bottom of the grouting section at the same depth as the lower end of the tunnel can maximize the grouting corrective effect.

Feasibility Analysis on Implement of Freeze Roadway Cooling Technology in Coal Mine of Heilongjiang Province

2012 ◽  
Vol 204-208 ◽  
pp. 1830-1833
Author(s):  
Jing Zhou ◽  
Xi Ming Liu ◽  
Xian Li Qin ◽  
Shu Ren Xing
Keyword(s):  
Constant Temperature ◽  
Coal Mine ◽  
Soil Layer ◽  
Reference Value ◽  
Frozen Soil ◽  
Feasibility Analysis ◽  
Geological Condition ◽  
Heilongjiang Province ◽  
Geographical Position ◽  
Cooling Technology

Freeze roadway cooling technology is delivering cold quantity to cooling underground face by storage cooling energy in strata, and the effect of storaging cold is critical. The geographical position and geological condition of coal mine in Heilongjiang Province has remarkable characteristics. The feasibility of freeze roadway cooling measure was demonstrated on temperature, geothermal, constant temperature strata and frozen soil layer, etc. by analyzed its advantage adequately. The measure provides a new idea which suits the native situation for prevent the heat-harm in coal mine, it also has the realistic reference value and is worth popularizing.

A study of the 20 January 1982 earthquake near Great Nicobar Island, India

1983 ◽  
Vol 73 (4) ◽  
pp. 1139-1159
Author(s):  
P. N. Agrawal
Keyword(s):  
Future Development ◽  
Bay Of Bengal ◽  
East Coast ◽  
Civil Engineering ◽  
Nicobar Island ◽  
Engineering Structures ◽  
Ground Fissures ◽  
Isoseismal Map ◽  
Damage Data ◽  
Civil Engineering Structures

abstract An earthquake of MS = 6.3 occurred on 20 January 1982 near the east coast of Great Nicobar Island (in the Bay of Bengal), India and caused great panic among the inhabitants. Ground Fissures and damage to civil engineering structures was also caused. A study comprised of the recording of aftershocks and their migration, the preparation of an isoseismal map, and the compilation of other damage data is presented. Some recommendations have been made to permit suitable safeguards in future development.

scholarly journals Land Subsidence and Ground Fissures in Beijing Capital International Airport (BCIA): Evidence from Quasi-PS InSAR Analysis

2019 ◽  
Vol 11 (12) ◽  
pp. 1466 ◽  
Author(s):  
Mingliang Gao ◽  
Huili Gong ◽  
Xiaojuan Li ◽  
Beibei Chen ◽  
Chaofan Zhou ◽  
...  
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Land Subsidence ◽  
Deformation Rate ◽  
Normal Operation ◽  
Integrated Analysis ◽  
Ground Fissure ◽  
Ground Fissures ◽  
International Airport ◽  
Series Analysis

Land subsidence is a global environmental geological hazard caused by natural or human activities. The high spatial resolution and continuous time coverage of interferometric synthetic aperture radar (InSAR) time series analysis techniques provide data and a basis for the development of methods for the investigation and evolution mechanism study of regional land subsidence. Beijing, the capital city of China, has suffered from land subsidence for decades since it was first recorded in the 1950s. It was reported that uneven ground subsidence and fractures have seriously affected the normal operation of the Beijing Capital International Airport (BCIA) in recent years before the overhaul of the middle runway in April 2017. In this study, InSAR time series analysis was successfully used to detect the uneven local subsidence and ground fissure activity that has been gradually increasing in BCIA since 2010. A multi-temporal InSAR (MT-InSAR) technique was performed on 63 TerraSAR-X/TanDem-X (TSX/TDX) images acquired between 2010 and 2017, then deformation rate maps and time series for the airport area were generated. Comparisons of deformation rate and displacement time series from InSAR and ground-leveling were carried out in order to evaluate the accuracy of the InSAR-derived measurements. After an integrated analysis of the distribution characteristics of land subsidence, previous research results, and geological data was carried out, we found and located an active ground fissure. Then main cause of the ground fissures was preliminarily discussed. Finally, it can be conducted that InSAR technology can be used to identify and monitor geological processes, such as land subsidence and ground fissure activities, and can provide a scientific approach to better explore and study the cause and formation mechanism of regional subsidence and ground fissures.

scholarly journals Activity Characteristics and Safety distance of Gaoliying Ground Fissure in Beijing

2019 ◽  
Vol 79 ◽  
pp. 02009
Author(s):  
Haigang Wang ◽  
Tongchun Qin ◽  
Haipeng Guo ◽  
Juyan Zhu ◽  
Yunlong Wang ◽  
...  
Keyword(s):  
Ground Water ◽  
Land Subsidence ◽  
Groundwater Level ◽  
Hanging Wall ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Rapid Decrease ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Safety Distance

In all ground fissures in Beijing, Gaoliying Ground Fissure has characteristics of highly activity, and it cause serious damages on constructoins. With the distribution as well as the development of land subsidence and the change of the groundwater level, a series of work has been conducted to explain the mechanism of the formation of Gaoliying Ground Fissure. For example, field damage investigations and trench observations were used to define the affected distance of ground fissure; three-dimensional deformation was monitored to determine active characteristic of ground fissure. This paper points out that Gaoliying ground fissure is controlled by Huangzhuang-Gaoliying Fault, which mainly moves in the vertical direction. The rapid decrease of the ground water level greatly increases the development of ground fissure. The distance of damaged zones affected by ground fissure in the hanging-wall of the fault reaches 49.5m, and the distance of damaged zones in the footwall of the fault is 17.5 m. A suggested safety distance of type-one and type-two buildings is 100 m. For type-three buildings, the suggested safety distance is 80 m.

Friction Structure Effect Analysis of Granular Materials in Foundation Soil

2012 ◽  
Vol 591-593 ◽  
pp. 1083-1088
Author(s):  
Chang Dan Wang ◽  
Shun Hua Zhou ◽  
Hui Su
Keyword(s):  
Stress Distribution ◽  
Granular Materials ◽  
Soil Layer ◽  
Stress Transfer ◽  
Fine Sand ◽  
Structure Effect ◽  
Additional Stress ◽  
Foundation Soil ◽  
Effect Analysis ◽  
Boussinesq Solution

To research and analyze the additional stress distribution and change of granular materials, the model tests are used to observe vertical additional stress in different position and depth. And the comparison between observed values and theoretical values is conducted to analyze the transmission and attenuation of additional stress in granular materials. The research results show that calculated values are based on Boussinesq solution which ignores the property of soil layer (materials), the distribution of additional stress for fine sand which belongs to granular materials is largely deviated from theoretical value. For granular materials, inner friction structure effect is evident influence to additional stress transfer. And continue using calculation method which is based on continuum materials will have bigger difference and even wrong.

Field measurements of soil thermal conductivity

1986 ◽  
Vol 23 (1) ◽  
pp. 51-59 ◽  
Author(s):  
L. E. Goodrich
Keyword(s):  
Thermal Conductivity ◽  
Soil Layer ◽  
Field Measurements ◽  
Soil Conditions ◽  
Soil Composition ◽  
Soil Thermal Conductivity ◽  
Marine Clay ◽  
Engineering Structures ◽  
Seasonal Differences ◽  
Phase Relationships

Data representing the seasonal variation of thermal conductivity of the ground at depths within the seasonally active freezing/thawing zone are presented for a number of different soil conditions at four sites across Canada. An inexpensive probe apparatus suitable for routine field measurements is described.In all the cases examined, significant seasonal variations were confined to the first few decimetres. In addition to distinct seasonal differences associated with phase change, quite large changes occurred during the period when the soil was thawed in those cases where seasonal drying was possible. Below the seasonally active zone, thawed soil conductivities did not differ greatly among the three nonpermafrost sites in spite of soil composition ranging from marine clay to sandy silt. The data suggest that, even within a given soil layer, quite significant differences in thermal conductivity may be encountered in engineering structures such as embankments, presumably because of differences in drainage conditions. Key words: thermal conductivity, field measurements, phase relationships, drying, permafrost, clay, silt, peat.

Research Advances in the Interaction among Stratum-Ground Fissure-Tunnel under Subway Dynamic Loading

2012 ◽  
Vol 226-228 ◽  
pp. 1513-1516 ◽  
Author(s):  
Li Qun Yuan ◽  
Hong Jia Liu ◽  
Yu Ming Men
Keyword(s):  
Dynamic Loading ◽  
Dynamic Interaction ◽  
Subway Tunnel ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Term Operation ◽  
Geological Disaster ◽  
Under Construction

Ground fissure is a kind of serious geological disaster. There will be more unprecedented challenges during the construction of the urban subway in ground fissures-developed zone. How to ensure the long-term operation safety of the subway crossing ground fissure belts are the first problems for the subway under construction in the cities with ground fissure developed. One of the important problems is that dynamic interaction and disaster effect control among ground fissure-stratum-subway tunnel under subway dynamic loading, which is also the important problem to be solved in the engineering. This problem involves the following three aspects: (a) the determination of subway dynamic loading; (b) the structure dynamic response of subway tunnel; (c) the interaction among stratum-ground fissure-subway tunnel. According to make a comment on these researches, some issues which are necessary to carry out in this field are suggested.

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