A design method for drilled piers in soft rock

1987 ◽  
Vol 24 (1) ◽  
pp. 126-142 ◽  
Author(s):  
R. K. Rowe ◽  
H. H. Armitage

A new procedure for the design of drilled piers socketed into soft rock is presented and the selection of design parameters discussed. The design method is based on (1) satisfying a specified design settlement criterion and (2) checking to ensure that there is an adequate factor of safety against collapse. The design allows consideration of the possibility of some slip occurring at the pier–rock interface under working load conditions.The design procedure is illustrated by a series of detailed calculations relating to two piers in Queenston shale and the observed behaviour of these piers is compared with design expectations. It is shown that these piers satisfied the design settlement criterion while having a significant proven factor of safety against collapse. Key words: rock, piers, piles, settlement, bearing capacity, design.

Author(s):  
T. Paulay ◽  
W. J. Goodsir

To complement existing capacity design procedures used in New Zealand for reinforced concrete buildings in which earthquake resistance is provided by ductile frames or ductile structural walls, an analogous methodology is presented for the design
of ductile hybrid structures. Modelling and types of structures in which the mode of wall contribution is different are briefly described. A step by step description of a capacity design procedure for a structural system in which fixed base ductile frames and walls, both of identical height, interact, is presented. The rationale for each step is outlined and, where necessary, evidence is offered for the selection of particular design parameters and their magnitudes. A number of issues which require further study are briefly outlined. These relate to irregularity in layout, torsional effects, diaphragm flexibility, shortcomings in the predictions for dynamic shear demands in walls, and to limitations of the proposed design procedure. It is believed that the methodology is logical, relatively simple and that it should ensure, when combined with appropriate detailing, excellent seismic structural response.


2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.


2020 ◽  
pp. 107754632092393
Author(s):  
Yongqiang Gong ◽  
Liang Cao ◽  
Simon Laflamme ◽  
James Ricles ◽  
Spencer Quiel ◽  
...  

The motion of cladding systems can be leveraged to mitigate natural and man-made hazards. The literature counts various examples of connections enhanced with passive energy dissipation capabilities at connections. However, because such devices are passive, their mitigation performance is typically limited to specific excitations. The authors have recently proposed a novel variable friction cladding connection capable of mitigating hazards semi-actively. The variable friction cladding connection is engineered to transfer lateral forces from the cladding element to the structural system. Its variation in friction force is generated by a toggle-actuated variable normal force applied onto sliding friction plates. In this study, a multiobjective motion-based design methodology integrating results from the previous work is proposed to leverage the variable friction cladding connection for nonsimultaneous wind, seismic, and blast hazard mitigation. The procedure starts with the quantification of each hazard and performance objectives. It is followed by the selection of dynamic parameters enabling prescribed performance under wind and seismic loads, after which an impact rubber bumper is designed to satisfy motion requirements under blast. Last, the peak building responses are computed and iterations conducted on the design parameters on the satisfaction of the motion objectives. The motion-based design procedure is verified through numerical simulations on two example buildings subjected to the three nonsimultaneous hazards. The performance of the variable friction cladding connection is also assessed and compared against different control cases. Results show that the motion-based design procedure yields a conservative design approach in meeting all of the motion requirements and that the variable friction cladding connection performs significantly well at mitigating vibrations.


Author(s):  
K A Edge ◽  
K R A Figueredo

An adaptive controller design procedure has been applied to an electrohydraulic servo-system. Detailed accounts are provided on applying the design method and on initializing the controller free design parameters. Experimental results demonstrate the ability of the adaptive controller to maintain consistently good model following behaviour under changing operating conditions.


2013 ◽  
Vol 444-445 ◽  
pp. 1446-1453
Author(s):  
Zhe Ou ◽  
Cong Xin Chen ◽  
Guan Wen Cheng ◽  
Yun Zheng

The evaluation of stability and reliability of support system for tunnel weak surrounding rock are difficult issues of concern in rock and soil engineering. Aiming at the problem of parameter design and reliability evaluation of tunnel weak surrounding rock and bolt-shotcrete support system, the deformation, failure mechanism and physical mechanical properties of weak surrounding rock are analyzed as well as the mechanism of bolt-shotcrete support in soft rock is studied. And the reliability analysis equation of bolt-shotcrete support in two kinds of weak surrounding rock (nearly horizontal layered mechanics medium and continuum mechanics medium) is established. The quantitative soft rock supporting theory is introduced into the reliability analysis equation. The calculation formula of two important design parameters of anchoring force and bolt spacing in bolt-shotcrete support is established. Finally an engineering example is adopted to prove the rationality of the calculation results. Therefor this paper provides theoretical basis and design method for supporting structure design and reliability evaluation of tunnel weak surrounding rock.


2016 ◽  
Vol 22 (2(99)) ◽  
pp. 48-51
Author(s):  
D.S. Kalynychenko ◽  
◽  
Ye.Yu. Baranov ◽  
M.V. Poluian ◽  
◽  
...  

2016 ◽  
Vol 106 (10) ◽  
pp. 357-362
Author(s):  
Yudong MAO ◽  
Jianzhong LI

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110343
Author(s):  
Mei Yang ◽  
Yimin Xia ◽  
Lianhui Jia ◽  
Dujuan Wang ◽  
Zhiyong Ji

Modular design, Axiomatic design (AD) and Theory of inventive problem solving (TRIZ) have been increasingly popularized in concept design of modern mechanical product. Each method has their own advantages and drawbacks. The benefit of modular design is reducing the product design period, and AD has the capability of problem analysis, while TRIZ’s expertise is innovative idea generation. According to the complementarity of these three approaches, an innovative and systematic methodology is proposed to design big complex mechanical system. Firstly, the module partition is executed based on scenario decomposition. Then, the behavior attributes of modules are listed to find the design contradiction, including motion form, spatial constraints, and performance requirements. TRIZ tools are employed to deal with the contradictions between behavior attributes. The decomposition and mapping of functional requirements and design parameters are carried out to construct the structural hierarchy of each module. Then, modules are integrated considering the connections between each other. Finally, the operation steps in application scenario are designed in temporal and spatial dimensions. Design of cutter changing robot for shield tunneling machine is taken as an example to validate the feasibility and effectiveness of the proposed method.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Zhe Liu

Double primary support structures could effectively solve the problem of large deformation of surrounding rock for soft rock tunnels. However, the mechanical behavior of this new support structure is still incomplete, and the design method should be revised. Based on the theory of energy conversion, this paper analyzes the support characteristic curve of double primary support and puts forward the dynamic design method of double primary support. Considering that the secondary lining can be set after monitoring the deformation amount and deformation rate of the first primary support, its support parameters can be dynamically adjusted according to the actual situation. By applying the double primary support design method in the Maoxian tunnel of Chenglan Railway, the field monitoring results show that the double primary support has a significant effect on the energy release of surrounding rocks, greatly reducing the load acting on the secondary lining and ensuring the safety and reliability of the tunnel structure.


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