Research on the Bearing Capacity for Rock Bolt Crane Girder in the Underground Powerhouse of Large Hydropower Station

2011 ◽  
Vol 255-260 ◽  
pp. 3563-3567
Author(s):  
Jian Bin Xie ◽  
Tian Chun He ◽  
Ji Yao ◽  
Chen Bo Zi
Keyword(s):  
Bearing Capacity ◽  
Design Criterion ◽  
Rock Bolt ◽  
Hydropower Station ◽  
Safe Operation ◽  
Underground Powerhouse ◽  
Geological Conditions ◽  
Enterprise Standard ◽  
The Stability ◽  
Rock Section

In this paper, according to the reality that there is no mature Chinese national design criterion but partial enterprise standard for rock bolt crane girder in the underground powerhouse of large hydropower station up to now. Based on the geological conditions, the rock bolt crane girder was designed by using method of rigid body equilibrium. The reinforced anchoring measures for rock bolt crane girder in undesirable geology were studied subsequently by the experience of analogous projects. The stability of rock bolt crane girder in underground powerhouse was analyzed and evaluated by Finite Element Method (FEM). Then the bearing capacity of crane beam was researched by means of bearing testing. The results show FEM is practicable to evaluate the stability of the rock bolt crane girder and to guide the rock bolt crane girder designing. The results also show the reinforced anchoring measures are appropriate to displace the undesirable surrounding rock section by using concrete. The results of bearing testing show that the design of rock bolt crane girder and its anchoring measures are rational, and crane girder can meet to the requirement of safe operation.

Research on Stability Analysis of Rock Bolt Crane Girder Needed

2011 ◽  
Vol 250-253 ◽  
pp. 2622-2625
Author(s):  
Heng Xiang Zheng ◽  
Rong He ◽  
Xiao Yang Huang
Keyword(s):  
Reinforced Concrete ◽  
Rigid Body ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Rock Bolt ◽  
Hydropower Station ◽  
Underground Powerhouse ◽  
Equilibrium Method ◽  
Shear Yield ◽  
The Stability

Rock bolt crane girder is a structure form which is widely used in the underground powerhouse of hydropower station. It makes reinforced concrete anchored in the underground powerhouse rock using anchor rod, and makes the reinforced concrete, anchor rod and surrounding rock work together to resist the load. Stability has been a common problem in the realm of engineered construction. This article will analysis the stability of the rock bolt crane girder in a underground powerhouse of hydropower station by using the traditional rigid body limit equilibrium method and the finite element method, and give several destroying forms. The results show that the rigid body limit equilibrium method is flawed, need to be corrected; In overload cases, the contact surface of girder and rock crack, it turns the damage to the bottom O point at the end; When it is simulated by the strength storage method, the crane girder's shear yield slips the damage along the base.

Mechanics Analysis of Grade V Surrounding Rock Primary Support in Maanziliang Tunnel

2012 ◽  
Vol 164 ◽  
pp. 414-417
Author(s):  
Jia Ming Han
Keyword(s):  
Finite Element ◽  
Safety Factor ◽  
Surrounding Rock ◽  
Qinling Mountains ◽  
The Finite Element Method ◽  
Highway Tunnel ◽  
Geological Conditions ◽  
The Stability ◽  
Primary Support ◽  
Rock Section

Commonly used finite element strength reduction to calculate the safety factor of slope，to analyze the stability of the slope[1～3]. Recently it also proposed the methods to evaluate the safety factor for the stability of surrounding rock of underground chambers and supporting structural mechanics[4～6]. For Qinling Mountains of the complex geological conditions in the Maanziliang highway tunnel, this article use the finite element method from the bolt resist tension, bolt length, the force of sprayed layer of concrete to computing gradeⅤsurrounding rock section of primary support safety factor, to give evaluation to support mechanics of the Maanziliang tunnel.

Establishment and Application of Microseismic Monitoring System to Deep-Buried Underground Powerhouse

2013 ◽  
Vol 838-841 ◽  
pp. 889-893
Author(s):  
Biao Li ◽  
Feng Dai ◽  
Nu Wen Xu ◽  
Chun Sha
Keyword(s):  
Rock Mass ◽  
Monitoring System ◽  
Wave Velocity ◽  
Microseismic Monitoring ◽  
Surrounding Rock ◽  
P Wave ◽  
Monitoring Method ◽  
Underground Powerhouse ◽  
Geological Conditions ◽  
The Stability

The right bank underground powerhouse of Houziyan hydropower station is a typical deep-buried type with high geostress and complicated geological conditions. To monitor and analyze the stability of surrounding rock mass during continuous excavation of the powerhouse excavation and locate the potential failure zones, an ESG (Engineering Seismology Group) microseismic monitoring system manufactured in Canada was installed in April, 2013. The wave velocity of the monitoring system was determined through fixed blasting tests. And the average location error is the minimum while P-wave velocity is 5700m/s, less than 10m and meeting the system request. By combining the temporal and spatial distribution regularity of microseimic events with field excavation, micro-crack clusters and potential instability zones were identified and delineated. The results will provide a reference for later excavations and supports of the underground powerhouse. Furthermore, a new monitoring method can also be supplied for the stability analysis of surrounding rock mass in deep-buried underground powerhouses.

Stability Analysis of Surrounding Rocks of Underground Powerhouse in a Hydropower Station

2014 ◽  
Vol 1030-1032 ◽  
pp. 1068-1073
Author(s):  
Jun Hu ◽  
Xiao Peng Yu
Keyword(s):  
Stability Analysis ◽  
Side Wall ◽  
Hydropower Station ◽  
Computation Result ◽  
Underground Powerhouse ◽  
Distribution Rules ◽  
High Side ◽  
Underground Caverns ◽  
The Stability ◽  
Supporting Structures

The underground powerhouse of a hydropower station is a typical large-span and high side wall cavern group. The stability analysis of high side wall and the rock between caverns is key for cavern design. Based on the process of excavation and anchorage of underground caverns, FLAC3D numerical modeling technique is used to dynamically analyze the distribution rules and variation features of the second stress field, displacement field plastic zones in the rock masses surrounding the caverns before construction of anchorage support and the loads carried by the supporting structures. The computation result shows that the opening's lay out, construction sequence and support parameters are rational.

scholarly journals Experimental justification of the stability of the floating unit

2021 ◽  
Vol 264 ◽  
pp. 01054
Author(s):  
Vladimir Zimnyukov ◽  
Marina Zborovskaya ◽  
Vasiliy Fartukov ◽  
Anton Zaitsev
Keyword(s):  
Bearing Capacity ◽  
Power Unit ◽  
Hydroelectric Power ◽  
Static Loads ◽  
Geological Conditions ◽  
Wide Range ◽  
Vertical Displacements ◽  
Shear Characteristics ◽  
Experimental Justification ◽  
The Stability

One of the main tasks arising when installing a floating hydroelectric power unit on a foundation without preliminary excavation is a thorough justification of the shear stability and bearing capacity of the "floating hydroelectric power unit - foundation" system on a complex geological massif. Failure to take into account these factors can lead to serious consequences during the landing of the structure in the target and further operation. It should be emphasized that this problem still includes a number of difficulties and does not always allow obtaining exact solutions in a volumetric setting. Based on the selection of a wide range of model materials, bases of various capacities were modelled for four models. In this case, the shear real characteristics of alluvial soils and their change after reinforcing cementation were taken into account. The studies were carried out on 4 models under static loads with bringing them to destruction. The models reproduced the real geological conditions at the base of the block, simulated deformation, and shear characteristics. Indicator diagrams of displacements, damage patterns, and generalized safety factors for bearing capacity were obtained. Model tests have shown that reinforcing cementation reduces not only the values of horizontal and vertical displacements of structures but also leads to a significant increase in the safety factor.

Formation and Stablity of the Sky Pond Landslide Dam, China

2011 ◽  
Vol 243-249 ◽  
pp. 3189-3200 ◽  
Author(s):  
Yan Hui Song
Keyword(s):  
Yellow River ◽  
Limit Equilibrium ◽  
Landslide Dam ◽  
Equilibrium Analysis ◽  
Qualitative Assessment ◽  
Hydropower Station ◽  
The Yellow River ◽  
Geological Conditions ◽  
Dammed Lake ◽  
The Stability

The Sky Pond landslide dam is located in Muchang valley, a branch of the Yellow River branches. From this point it is about 6Km to the mouth of the valley from where the Yellow River flows 0.8Km downwards to the planned Jishi gorge hydropower station. The Sky Pond landslide dam is actually formed by two landslides from both the left and right bank slopes and completely blocks the seasonal river channel. The volume of the landslide dam is about 14 millions m3 with 2.37 millions m3 water stored in the dammed lake under the condition of perennial mean water level. Because (1) the dam body is large in width and thickness; (2) the dammed lake water is small both in volume and weight compared to the landslide dam; (3) recharge to the dammed lake is basically the same as the discharge every year; and (4) there is a natural spillway in the dam body, the landslide dam is present at least 750 years after its formation. Although landslide dams which have existed for several hundreds to thousands of years are generally considered as stable, there are remains which may fail catastrophically. In order to analyze the stability of the Sky Pond landslide dam and provide justification for the future engineering decisions, this paper describes the engineering geological conditions near the landslide dam and the characteristics of the dam body, and a detailed discussion of the formation mechanism of the landslide. Based on engineering geology investigation, a qualitative assessment of the stability of the dam and an analysis of the probability of dam overtopping and piping is carried out. Limit equilibrium analysis has been used to calculate the stability of the dam slope under various operational conditions. Results of the stability analyses indicate that the Sky Pond landslide dam should remain stable and does not present a potential theat to the planned hydropower station.

Analysis for the Seepage Stability of the Upstream Cofferdam of One Hydropower Station

2013 ◽  
Vol 441 ◽  
pp. 286-290
Author(s):  
Yu Lin Yuan ◽  
Yun Feng Peng
Keyword(s):  
Safety Factor ◽  
Theoretical Basis ◽  
Circle Method ◽  
Control Design ◽  
Hydropower Station ◽  
Software Analysis ◽  
Seepage Control ◽  
Geological Conditions ◽  
The Stability

According to the geological conditions of upstream cofferdam and foundation of the hydropower station, analysis for the seepage of the upstream cofferdam used SEEP/W module of Geo-studio software. Analysis for the stability used SLOPE/W module with Swedish circle method and Bishop method. Safety factor of the upstream and downstream in different conditions was obtained. The results show that the design of the upstream cofferdam was reasonable, and it will provide theoretical basis for Seepage control design of cofferdam.

Numerical Simulation of Excavation of Abutment Slope at Left Bank in Dagangshan Hydropower Station

2012 ◽  
Vol 238 ◽  
pp. 313-316
Author(s):  
Kun Yang ◽  
Zhi Chao Ma ◽  
Hao Han
Keyword(s):  
Element Model ◽  
Hydropower Station ◽  
Left Bank ◽  
Geological Conditions ◽  
Potential Failure ◽  
Deformation Stress ◽  
The Stability ◽  
Dagangshan Hydropower Station ◽  
Failure Location ◽  
The Finite Element Model

The abutment slope at left bank in Dagangshan hydropower station has complex geological conditions with deep fractures, developed faults and unloading crack. The excavation will influence the stability of the slope. To evaluate the slope stability, the finite element model of this abutment slope was built in this paper to study the deformation, stress and plastic zone distribution of the slope during the excavation. The potential failure location of the slope is forecasted, some suggestions are proposed to be helpful to keep the stability of the slope.

scholarly journals Formation Mechanism and Stability Analysis of the Hejia Landslide

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Hao Zhang ◽  
Zaiqiang Hu ◽  
Xingzhou Chen ◽  
Hongru Li
Keyword(s):  
Formation Mechanism ◽  
Soft Rock ◽  
Normal Operation ◽  
Hydropower Station ◽  
Rock Interaction ◽  
Reservoir Impoundment ◽  
Layered Slope ◽  
Geological Conditions ◽  
Slope Structure ◽  
The Stability

The existing research data show that, after reservoir impoundment, due to the repeated rise and fall of water level and water-rock interaction, the mechanical parameters of landslide are reduced, which will have an adverse effect on the stability of landslide. Therefore, sufficient attention must be paid to the stability of slope after reservoir impoundment. Hejia landslide is the largest landslide near the bank of Miaojiaba hydropower station, and its stability plays an important role in the normal operation of the hydropower station. Through field investigation and analysis of regional geological conditions, it is concluded that Hejia landslide is a large-scale landslide, through long-term sliding-bending deformation; it is generated from the external hard rock with thick layers and sliding zone for layered soft rock; the formation mechanism of landslide is as follows: (1) high-steep and hard-soft layered slope is the slope structure condition that caused the large landslide; (2) the existence of thick soft rock belt provides material conditions for the formation of slip surface; (3) certain air conditions provide displacement space for the separation and disintegration of the sliding body, and the landslide is stable at present. Numerical analysis results show that reservoir impoundment will adversely affect the stability of landslide. In order to ensure the normal operation of power station, certain engineering measures must be taken to treat Hejia landslide. After taking measures, years of monitoring data show that the deformation of Hejia landslide tends to be stable, and the current operation is normal, indicating that the engineering treatment measures are reasonable and feasible.

Design and Application of Rock Bolt Foundation in Mountain Cable Crane

2014 ◽  
Vol 578-579 ◽  
pp. 745-750
Author(s):  
Jin Sheng Lei ◽  
Xue Ting Cao ◽  
You Wei Zeng ◽  
Fei Liu
Keyword(s):  
Bearing Capacity ◽  
Design Theory ◽  
Failure Modes ◽  
Effective Means ◽  
Reference Value ◽  
Rock Bolt ◽  
Mountainous Area ◽  
Geological Conditions ◽  
Cable Crane ◽  
Force Calculation

Restricted by the construction environment, the cable crane is an effective means to resolve the transportation of materials and component in the mountainous area. Compared with traditional gravity anchor base, cable crane fixed on the rock bolt foundation can take advantage of the bearing capacity of bedrock, and the construction method is simple and of good economic benefit. With the effect of the construction methods, design theory of geological conditions, and other factors, however, force calculation is much complicated. By analyzing the failure modes of rock bolt foundation, anchor foundation bearing capacity factors and multi anchorage effect on anchoring force, we studied the design process of rock bolt foundation, geotechnical strength parameters and the safety coefficient of reference value. Further, a construction way is proposed to improve the basic bearing capacity of rock bolt. Combing with engineering examples, we also demonstrated the security and reliability of the design method .

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