scholarly journals Deformation Monitoring of Geomechanical Model Test and Its Application in Overall Stability Analysis of a High Arch Dam

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Baoquan Yang ◽  
Lin Zhang ◽  
Enlong Liu ◽  
Jianhua Dong ◽  
Honghu Zhu ◽  
...  

Geomechanical model testing is an important method for studying the overall stability of high arch dams. The main task of a geomechanical model test is deformation monitoring. Currently, many types of deformation instruments are used for deformation monitoring of dam models, which provide valuable information on the deformation characteristics of the prototype dams. However, further investigation is required for assessing the overall stability of high arch dams through analyzing deformation monitoring data. First, a relationship for assessing the stability of dams is established based on the comprehensive model test method. Second, a stability evaluation system is presented based on the deformation monitoring data, together with the relationships between the deformation and overloading coefficient. Finally, the comprehensive model test method is applied to study the overall stability of the Jinping-I high arch dam. A three-dimensional destructive test of the geomechanical model dam is conducted under reinforced foundation conditions. The deformation characteristics and failure mechanisms of the dam abutments and foundation were investigated. The test results indicate that the stability safety factors of the dam abutments and foundation range from 5.2 to 6.0. These research results provide an important scientific insight into the design, construction, and operation stages of this project.

2014 ◽  
Vol 919-921 ◽  
pp. 1244-1247 ◽  
Author(s):  
Ying Kui Wang ◽  
Ren Qiang Liao

The security researches of energy dissipation were always the focus in the High arch dams. Statistically, the trajectory type energy dissipation is the most widely used in the built high arch dams, and the protected plunge poor were always set downstream the dam body. However, the widely used protected plunge poor need large investment with the disadvantage of complicated operation and maintenance. Along with the construction of concrete high arch dam in the Southwest China, the “Reventment-Protected and Non-Bottom-Protected Plunge Pool” has been studied and proposed, which has the advantage of more simplified project design and more economy investment.


2012 ◽  
Vol 594-597 ◽  
pp. 1932-1935
Author(s):  
Hui Li ◽  
Zheng Zhong Wang ◽  
Xuan She

As a result of many high arch dams that are building and would be built in the south-west and north-west of China, arch dam is a kind of compressed thin buckle, not only effect by tension, but also by deformation. Thinner dam body with usage of increased levels of concrete and optimum designing, the local regions of high arch dams approach thin shell structure,which will lead to the structural buckling. Base on the above present condition, this paper would establish a series of generalized high and thin arch dam models whose height are 240m, and make theoretical analysis based on one of the crown- cantilever method- differential method for them, which attempts to provide a new method for the" critical flexibility coefficient ". At last, this paper would provide the relation between coefficient and buckling stability of high arch dam


2020 ◽  
Vol 20 (8) ◽  
pp. 3604-3614
Author(s):  
Jingtai Niu ◽  
Xiang Luo ◽  
Zhiping Deng ◽  
Yang Zhang ◽  
Yingjia Guo ◽  
...  

Abstract This paper presents a proposed model for monitoring the stress on a super-high arch dam during construction. Using mathematics, mechanics, and dam engineering principles, the mathematical expressions of the self-weight component of the dam prior to and following the sealing of the bottom of the arch were derived. The visco-elastoplastic constitutive model of dam concrete during construction was identified and used to develop a stress monitoring model for a super-high arch dam. Based on in-situ stress monitoring data collected during the construction of a super-high arch dam, the stress monitoring model was applied to a super-high arch dam accounting for future impoundment, and the key components of the monitoring model were isolated. The results show that the model has high fitting accuracy and incorporates an appropriate selection of factors affecting dam stress. The hydrograph of each component conforms to the structural characteristics of super-high arch dams during construction. This model overcomes the limitations of applying the complete self-weight of the dam body on the cantilever beam and was validated using data from a super-high arch dam construction project. Thus, this paper provides evidence for a safety monitoring model for super-high arch dams during construction.


2009 ◽  
Vol 417-418 ◽  
pp. 541-544
Author(s):  
Zai Tie Chen

In view of the randomness in terms of high arch dam load, resistance and failure calamity loss as well as the fuzziness in terms of evaluation conclusion, a high arch dam risk evaluation system is established by means of risk analysis method. Natural factors, structural factors and human factors that lead to high arch dam failure are summed up on the basis of statistics. Through qualitative analysis coupled with quantitative estimation, it is determined that high arch dams generally involve five major failure modes: abutment rock mass destabilization, excess cracking, arch dam & dam foundation entire destabilization, extreme dam-overflow and destabilization of dam body along base plane. The state functions of individual major failure modes are established. An approach is made to the correlativity among the major failure modes and among the random variables within individual failure modes, and it is suggested that risk rate, economic loss risk value and life loss risk value should be used to assess the risk of high arch dams. A certain high arch dam abutment instability risk evaluation has been provided.


2008 ◽  
Vol 385-387 ◽  
pp. 269-272 ◽  
Author(s):  
Zai Tie Chen

Risk analysis can overcome the weakness of conventional safety evaluation of high-arch dams where the random nature of the load and resistance effect are ignored and the failure mode and failure disaster loss are not taken into account. On the basis of statistical analysis of the data of the failure arch dams and faulty and perilous arch dams in the world, it is deduced that the failure of high arch dam is mainly caused by super elevation floods, highly intense earthquakes, mountain landslides, abnormal temperature variation, explosion load, etc. Five major failure modes for high arch dams are suggested, namely dam abutment rock instability, fundamental plane instability, entire entity instability, excess cracking and extreme dam overflow. Based on the study of the failure mechanism of the major failure modes, a state function is established to calculate the failure probability of the major failure modes. An approach is developed to obtain the statistical quantity and the regularities of distribution of the load and resistance random variables.


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