Optimization Design Study on Variable Stiffness of the Pile Raft Foundation in High-Rise Building

2011 ◽  
Vol 243-249 ◽  
pp. 2498-2502 ◽  
Author(s):  
Yong Le Li ◽  
Jiang Feng Wang ◽  
Qian Wang ◽  
Kun Yang
Keyword(s):  
Optimization Design ◽  
Variable Stiffness ◽  
Internal Force ◽  
Differential Settlement ◽  
Foundation Soil ◽  
High Rise ◽  
High Rise Building ◽  
Raft Foundation ◽  
Calculation Results ◽  
Pile Arrangement

The finite element calculation results indicated: interaction of the superstructure-the pile raft foundation-foundation, the stress of the pile raft foundation appeared "disc type" distribution, namely, was big in the middle, and was small in the edge. Generation of differential settlement was due to the upper structure secondary stress and raft internal force. Through adjusting the foundation soil stiffness and pile length, pile diameter and pile distance, the influence of variable stiffness on differential settlement was analyzed. The results showed that changing the pile arrangement and adjusting the stiffness of foundation soil was optimal scheme of the pile raft foundation in high-rise building.

Numerical Analysis on Interaction of Superstructure-Piled Raft Foundation-Foundation Soil

2011 ◽  
Vol 261-263 ◽  
pp. 1578-1583
Author(s):  
Yong Le Li ◽  
Jiang Feng Wang ◽  
Qian Wang ◽  
Kun Yang
Keyword(s):  
Design Method ◽  
Bending Moment ◽  
Load Sharing ◽  
Differential Settlement ◽  
Pile Head ◽  
Secondary Stress ◽  
Foundation Soil ◽  
Piled Raft Foundation ◽  
Raft Foundation ◽  
Soil Load

based on the finite element method of superstructure-the pile raft foundation-the foundation soil action and interaction are studied. Research shows that the common function is considered, fundamental overall settlement and differential settlement with the increase of floor of a nonlinear trend. The influence of superstructure form is bigger for raft stress, the upper structure existing in secondary stress, and the bending moment and axial force than conventional design method slants big; With the increase of the floors, pile load sharing ratio is reduced gradually,but soil load sharing ratio is increased. Along with the increase of the upper structure stiffness, the load focused on corner and side pile; Increasing thickness of raft, can reduce the certain differential settlement and foundation average settlement, thus reducing the upper structure of secondary stress and improving of foundation soil load sharing ratio, at the same time the distribution of counterforce on the pile head is more uneven under raft, thus requiring more uneven from raft stress, considering the piles under raft and the stress of soils to comprehensive determines a reasonable raft thickness, which makes the design safety economy. As the foundation soil modulus of deformation of foundation soil improvement, sharing the upper loads increases, counterforce on the pile head incline to average, raft maximum bending moment decrease gradually.

scholarly journals STUDY ON CONTROL CHARACTERISTICS OF ACTIVE VARIABLE STIFFNESS SYSTEM APPLIED TO A HIGH-RISE BUILDING

2000 ◽  
Vol 65 (531) ◽  
pp. 79-86 ◽  
Author(s):  
Motoichi TAKAHASHI ◽  
Takuji KOBORI ◽  
Tadashi NASU ◽  
Akihiro KUNISUE
Keyword(s):  
Variable Stiffness ◽  
High Rise ◽  
High Rise Building

scholarly journals Optimization Design of a Rain-Power Utilization System Based on a Siphon and Its Application in a High-Rise Building

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4848
Author(s):  
Jiaxin Yu ◽  
Jun Wang
Keyword(s):  
Energy Conversion ◽  
Optimization Design ◽  
Unit Length ◽  
Clean Energy ◽  
Energy Generation ◽  
Poor Quality ◽  
Maximum Energy ◽  
Theoretical Research ◽  
High Rise ◽  
High Rise Building

Rain falling from the sky is viewed as a clean energy source with a great potential, owing to the large amount of it and its zero pollution nature, the fact that it has scattered raindrops, and its characteristic rainfall concentration that promotes extensive research on harvesting and utilization. Here, we introduce a new approach to harvest rainwater on rooftops called the Rain-Power Utilization System, which is composed of an initial rainwater disposal system and multistage energy conversion system. Initial rainwater is discharged into a split-flow pipe due to its poor quality and impurities. Additionally, clean rainwater is accumulated in a storage pipe until the water level reaches a specified height, triggering siphonage for energy conversion. The same process is repeated in other storage pipes connected in series. Function relations among physical and dimension parameters have been established for further studies. A kind of simplified optimization algorithm has been proposed considering the maximum instantaneous power under the constraint of a permitted vacuum and maximum energy generation per unit length to find the model with an optimal height combination (hu, hd). The experimental prototype developed in proportion is used to verify theoretical research and conduct error analysis to establish an equation of annual energy generation for a high-rise building. Without building extra tanks, this paper presents an innovative approach to maximizing the use of energy in rain for high-rise buildings based on a siphon.

scholarly journals Design and Improvement of foundation soil for high-rise construction

2018 ◽  
Vol 170 ◽  
pp. 03001 ◽  
Author(s):  
Kwa Sally Fahmi ◽  
Mohammed Y. Fattah ◽  
Andrey Pustovgar
Keyword(s):  
Fem Analysis ◽  
Stone Columns ◽  
3D Fem ◽  
Foundation Design ◽  
Foundation Soil ◽  
Total Load ◽  
High Rise ◽  
Raft Foundation ◽  
Dimensional Finite Element ◽  
Current Design

The assessments were made in the current practice based on the design foundation of high-rise buildings in Moscow to find a method for improving the soil foundation. Many references showed that the current design was controlled by structural engineers. They commonly used the old methods of analysis, the first part was carried out for the design of the structure and architecture of high-rise building, the second part of the study was to explore the benefit of adopting the application of stone columns raft foundation design concept. A comparative study was made between the results of the 3-dimensional finite element (3D FEM) analysis in SCAD software. The results showed that the plate foundation of the building does not satisfy to carry the total load without some meaning of improvement. The 3D FEM by PLAXIS 3D showed that the used stone columns decreased the settlement because about 70-80% of the total building loads were carried by columns when the raft was placed in the stiff clay layer. The number of columns in the raft foundation can be significantly reduced, particularly if the soil had strong characteristics. The raft foundation settlement can be significantly reduced, particularly if the soil had strong characteristics.

scholarly journals STRESS-STRAIN STATE OF THE SYSTEM "COMBINED TOWER-REINFORCED CONCRETE FOUNDATION-FOUNDATION SOIL" OF HIGH-RISE STRUCTURES

2020 ◽  
pp. 29-37
Author(s):  
L. Mailyan ◽  
S. Yazyev ◽  
L. Sabitov ◽  
Yu. Konoplev ◽  
Oleg Radaykin
Keyword(s):  
Reinforced Concrete ◽  
High Strength ◽  
Physical Nonlinearity ◽  
Steel Shell ◽  
Structural System ◽  
Concrete Core ◽  
Foundation Soil ◽  
High Rise ◽  
Concrete Foundation ◽  
Calculation Results

The aim of the work was to evaluate the effectiveness of the system "combined tower-reinforced concrete foundation-foundation soil" for high-rise structures on the example of a wind power plant (wind turbine) with a capacity of 1.5-2.0 MW using computer modeling in the PC "Ansys". Thus, under the combined tower the article refers to high-rise building, consisting of two parts: the lower composite, the upper – in the form of a thin-walled core-shell closed profile. In both cases, the shell is a pipe with a weak taper. As an analogue, the WPP considered in foreign literature is adopted: the radius of the rotor is R=41 m, the height to the axis of the wind wheel is zhub=80 m. The shell is made of high-strength C355 steel and, unlike the analog in this work, the cavity of the lower part of the tower to a height of 20 m was filled with B60 class concrete. The modeling took into account the spatial work of the elements of the structural system and the physical nonlinearity of the materials from which they are made. At the same time, the Mises strength theory was used for steel, the Williams – Varnake theory for concrete, and the Drukker – Prager theory for the foundation soil. Comparison of the calculation results with the analog showed that the destructive load of the tower increased by 37% due to filling the lower part of it with concrete, which indicates the effectiveness of the proposed solution. In this case, the destruction of the tower with a concrete core and without it occurred from the loss of local stability of the steel shell at the level of the junction of the tower with the foundation (with a compressed zone).

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