scholarly journals Safety Evaluation of Arch Dam Subjected to Underwater Contact Explosion

Mathematics ◽  
2021 ◽  
Vol 9 (22) ◽  
pp. 2941
Author(s):  
Xiaohua Zhao ◽  
Hongyuan Fang ◽  
Gaohui Wang ◽  
Yong Fan
Keyword(s):  
Damage Index ◽  
Safety Evaluation ◽  
Underwater Explosion ◽  
Middle Part ◽  
Arch Dam ◽  
Local Damage ◽  
Flood Discharge ◽  
Contact Explosion ◽  
Local Explosion ◽  
The Stability

The stability of an arch dam can be significantly damaged by an extreme underwater explosion. This study proposed a damage index for assessing the degree of local damage of an arch dam after the dam was subjected to an underwater explosion. The damage index was applied to assess local damage at the middle part of the dam, surcharge holes, and abutment. A model was developed to evaluate the stability of the entire dam based on the spatial distribution of damage and the damage on the base interface. Results showed that local explosion damage at flood discharge holes or abutments might cause instability of the arch dam. When the contact explosion action location is on the abutment, it only needs 310 kg to cause the overall damage of the arch dam, while when the action location is on the middle part of the dam, the quantity of explosive required is 2800 kg.

scholarly journals Numerical Investigation on Shape Optimization of Small-Spacing Twin-Well for Salt Cavern Gas Storage in Ultra-Deep Formation

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2859
Author(s):  
Haitao Li ◽  
Jingen Deng ◽  
Qiqi Wanyan ◽  
Yongcun Feng ◽  
Arnaud Regis Kamgue Lenwoue ◽  
...  
Keyword(s):  
Safety Evaluation ◽  
Gas Storage ◽  
Gas Pressure ◽  
Salt Cavern ◽  
Well Spacing ◽  
3D Geomechanical Model ◽  
The Stability ◽  
Bedded Rock Salt ◽  
Salt Cavern Gas Storage ◽  
Small Spacing

Small-spacing twin-well (SSTW) salt caverns have an extensive application prospect in thin or bedded rock salt formations due to their good performance, while they are rarely used in ultra-deep formations. The target strata depth of Pingdingshan salt mine is over 1700 m, and it is planned to apply an SSTW cavern to construct the underground gas storage (UGS). A 3D geomechanical model considering the viscoelastic plasticity of the rock mass is introduced into Flac3D to numerically study the influence of internal gas pressure, cavern upper shape and well spacing on the stability of an SSTW salt cavern for Pingdingshan UGS. A set of assessment indices is summarized for the stability of gas storage. The results show that the minimum internal gas pressure is no less than 14 MPa, and the cavern should not be operated under constant low gas pressure for a long time. The cavern with an upper height of 70 m is recommended for Pingdingshan gas storage based on the safety evaluation and maximum volume. The well spacing has a limited influence on the stability of the salt cavern in view of the volume shrinkage and safety factor. Among the values of 10 m, 20 m and 30 m, the well spacing of 20 m is recommended for Pingdingshan gas storage. In addition, when the cavern groups are constructed, the pillar width on the short axis should be larger than that on the long axis due to its greater deformation in this direction. This study provides a design reference for the construction of salt cavern gas storage in ultra-deep formations with the technology of SSTW.

Reasonable Strength Criterion Research of High Arch Dam Based on Brittle Failure Constitutive Relation

2014 ◽  
Vol 578-579 ◽  
pp. 964-967
Author(s):  
Zhi Qiang Wang ◽  
Wen Biao Liu
Keyword(s):  
Constitutive Relation ◽  
Brittle Failure ◽  
Concrete Strength ◽  
Safety Evaluation ◽  
Strength Criterion ◽  
Arch Dam ◽  
Dam Failure ◽  
Dam Safety ◽  
High Arch Dam ◽  
Triaxial Strength

The brittle failure finite element method is widely used in arch dam safety evaluation, but it also has some problems, the concrete strength criterion is different, the dam failure range is different. This article first introduces brittle failure constitutive relation and three strength criterions, then takes a high arch dam as an example to compute, obtains some conclusions that the relative failure range of foundation plane corresponds to blaxial strength criterion is slightly bigger than the result of uniaxial strength criterion, is almost the same as the result of triaxial strength criterion. Because the influence of the third principal stress is compressed stress to the dam crack is taken into account under multiaxial strength criterion, therefore using multiaxial strength criterion is more reasonable.

scholarly journals Safety Evaluation of Underground Caverns Based on Monte Carlo Method

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Qifeng Guo ◽  
Zhihong Dong ◽  
Meifeng Cai ◽  
Fenhua Ren ◽  
Jiliang Pan
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Three Dimensional ◽  
Safety Evaluation ◽  
Cumulative Distribution ◽  
Three Dimensional Model ◽  
Maximum Displacement ◽  
The Monte Carlo Method ◽  
Underground Caverns ◽  
The Stability

In order to study the influence of joint fissures and rock parameters with random characteristics on the safety of underground caverns, several parameters affecting the stability of surrounding rock of underground caverns are selected. According to the Monte Carlo method, random numbers satisfying normal distribution characteristics are established. A three-dimensional model of underground caverns with random characteristics is established by discontinuous analysis software 3DEC and excavation simulations are carried out. The maximum displacement at the numerical monitoring points of arch and floor is the safety evaluation index of the cavern. The probability distribution and cumulative distribution function of the displacement at the top arch and floor are obtained, and the safety of a project is evaluated.

scholarly journals Piezoceramic-Based Damage Monitoring of Concrete Structure for Underwater Blasting

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1672 ◽  
Author(s):  
Jianfeng Si ◽  
Dongwang Zhong ◽  
Wei Xiong
Keyword(s):  
Damage Detection ◽  
Piezoelectric Transducer ◽  
Impact Load ◽  
Wavelet Packet ◽  
Blast Hole ◽  
Damage Index ◽  
Underwater Explosion ◽  
Damage Monitoring ◽  
Concrete Materials ◽  
The Impact

This paper developed a piezoelectric-transducer-based damage detection of concrete materials after blasting. Two specimens (with or without an energy-relieving structure) were subjected to a 40 m deep-underwater blasting load in an underwater-explosion vessel, and their damage was detected by a multifunctional piezoelectric-signal-monitoring and -analysis system before and after the explosion. Statistical-data analysis of the piezoelectric signals revealed four zones: crushing, fracture, damage, and safe zones. The signal energy was analyzed and calculated by wavelet-packet analysis, and the blasting-damage index was obtained after the concrete specimen was subjected to the impact load of the underwater explosion. The damage of the two specimens gradually decreased from the blast hole to the bottom of the specimen. The damage index of the specimen with the energy-relieving structure differed for the fracture area and the damage area, and the damage protection of the energy-relieving structure was prominent at the bottom of the specimen. The piezoelectric-transducer-based damage monitoring of concrete materials is sensitive to underwater blasting, and with wavelet-packet-energy analysis, it can be used for postblasting damage detection and the evaluation of concrete materials.

The Effect of Alloying Elements on the Stability of Centerline Segregation

2010 ◽  
Vol 297-301 ◽  
pp. 148-153 ◽  
Author(s):  
Mihály Réger ◽  
Balázs Verő ◽  
Ibolya Kardos ◽  
Péter Varga
Keyword(s):  
Carbon Activity ◽  
Middle Part ◽  
Steel Plates ◽  
Alloying Elements ◽  
Centerline Segregation ◽  
Quality Properties ◽  
Continuously Cast ◽  
The Stability ◽  
Hot Rolled

The paper deals with the stability of centerline inhomogenity of continuously cast slabs and hot rolled products. The centerline segregation is a disadvantageous failure of slabs which can affect the quality properties of the final products. During hot rolling of slabs the centerline segregation pattern will become thin and stretch and it can also be detected in the middle part of heavy plates and coils. It is a common experience that the centerline segregation of heavy plates can not be easily decreased by post heat treatment. The pattern of the centerline segregation was modeled physically by preparing a sandwich structure of steel plates with different levels of carbon and alloying elements. Homogenization experiments were performed and the samples were examined metallographically. Diffusional calculations proved the governing role of carbon activity which is influenced by the distribution of alloying elements.

Stability Analysis of Arch Dam Abutment

2013 ◽  
Vol 702 ◽  
pp. 3-6
Author(s):  
Ling Qiang Yang ◽  
Rui Gao
Keyword(s):  
Stability Analysis ◽  
Reliability Analysis ◽  
Arch Dam ◽  
Parallel Connection ◽  
Substructure Method ◽  
Stochastic Parameters ◽  
Connection System ◽  
In Series ◽  
The Stability

Safe analysis of the progressive slide is used to estimate the stability of arch dam. The space stochastic parameters are surveyed through considering the relativity of parameter. The stability reliability analysis can be divided into element, sub-structure or sub-system, system.etc. From element to system calculate abutment’s ability. Sub-structure is composed by elements parallel connection. System is composed by sub-structures in series. The substructure method is applied to study the interaction between arch dam and its abutment. In this paper, the weakness part of abutment was found by cracking analysis of the progressive slide, and the safe evaluation was given.

Seismic Safety Evaluation of High Arch Dams Using Concrete Damage Theory

2010 ◽  
Vol 29-32 ◽  
pp. 1476-1480
Author(s):  
Zhi Guo Niu ◽  
Jun Lu ◽  
Ri You
Keyword(s):  
Safety Evaluation ◽  
Nonlinear Behavior ◽  
Maximum Principal Stress ◽  
Arch Dam ◽  
Seismic Safety ◽  
Arch Dams ◽  
Earthquake Load ◽  
Concrete Damage ◽  
Damage Theory ◽  
High Arch Dams

To reasonably evaluate the seismic behavior of high arch dams, a damage plasticity model is adopted to simulate the dynamic nonlinear behavior of dam concrete for a hydropower station. Combining with the viscous-spring boundary and compressibility reservoir model, the maximum principal stress on upstream and downstream surfaces is obtained. The results show that the effects of material nonlinearity damage on the dynamic response of the arch dam are significant under earthquake load.

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