Construction Of High-rise Structures Research Articles

Wind-resistant reliability assessment of a super-high tower crane considering the randomness and correlation of turbulent spectral parameters

The need for wind-sensitive super-high tower cranes during the construction of high-rise structures has been growing, which makes it critical to assess the wind-resistant reliability of cranes. The accuracy of assessment is dominated by the refined simulation of real stochastic wind fields, which is usually based on the deterministic turbulent spectra including fixed spectral parameters. However, it might cause significant errors to estimate extreme responses of structures. Therefore, a simulation method for stochastic wind fields considering the randomness and correlation of turbulent spectral parameters is proposed in this study. The random functions of correlated spectral parameters are constructed based on several independent elementary random variables. A novel simulation method for stochastic wind fields involving the established random turbulent spectral functions is utilized to generate fluctuating wind samples at the Ma'anshan Yangtze River (MYR) Bridge site. In combination with the probability density evolution method, the stochastic response analysis and reliability assessment of wind-induced vibration of the crane are addressed. Results prove the effectiveness of the proposed approach in depicting probabilistic properties of real wind fields. Meanwhile, the wind-resistant comfort reliability of the tower crane is higher when considering the randomness and correlation of turbulent spectral parameters.

A Review on Construction Approach on Preliminary Stage at Best Location

Abstract: The construction of high rise structures in developed and developing countries have been widely used in their urban areas and semi-urban areas. These tall structures include residential apartment, commercial and semi-commercial apartment. Since the provision of these buildings have a larger area of construction, but constructed over less area. In analysis stage of the structure, significant characteristics like vertical load, horizontal load, superstructure design, foundation design takes place. But before that the architecture planning over the larger area has proposed. The selection of area of construction in this preliminary stage has not sufficient on comparing with structural design configurations and soil parameters is an important part should takes place before the planning of the construction area. The paper consists of the study of the past research based on the above title and after that conclusions have drawn based on the inferences of reviews. The result shows that location parameter based on the soil investigation report should be determined first for the usage of best SBC of soil of the selection of construction area. Keywords: Vertical Load, Soil Bearing Capacity (SBC), Tall Buildings, Foundation, Building Design.

Bacteria in Ultra-High-Performance Concrete - Review of Factors Affecting Durability

Durability is the most important aspect of the structure, but it is not the only aspect of the structure. We also need high workability, high strength, and high modulus of elasticity, high dimensional stability, low permeability, and chemical attack resistance, as well as a special self-healing capacity for construction of high rise structures, long-span precast/prestressed bridge girders, marine, aviation, and defense construction applications and special structures. According to several investigations, bacteria of the genus Bacillus are required to boost the self-healing potential of concrete. High-strength, self-compacting, fiber-reinforced, high performance, and bacte- rial self-healing concrete are required for special and high-rise constructions. In this study, we exclusively evaluate the bacterial effect of Genus Bacillus on various self-healing capabilities of concrete in terms of concrete durability. In our research, we also include ul- tra-high performance concrete, which is employed in constructions such as high-rise building construction, long-span pre- cast/prestressed bridge girders, maritime, aviation, and defense construction applications. In this situation, a new type of concrete is formed, which is referred to as Bacterial Ultra-High-Performance Concrete. This concrete will be employed in high-rise and special- purpose structures in the future because of its great durability and low maintenance cost. Keywords Durability.Ultra-high-performance concrete.Self-healing concrete. High-strength concrete.High- performanceconcrete.Bacterial concrete. Fiber-reinforced concrete

Effect of Aspect Ratio on High Rise Structures with Diagrid

Urbanization and population explosion in the present times has led to increase in demand for land and residencies but the availability of land is scare i.e reason a trend has evolved for construction of high rise structures in high rise structures major emphasis given to lateral load resisting systems. As diagrid structural system is lighter, stiffer and is effective in resisting the lateral loads, the present investigation carried out to study the performance diagrid on high rise structures varying aspect ratio. The study is carried out to observe the performance of diagrid structures ranging from 30 to 90 storeys. Diagrid structures are modelled with 3 storey module and performance of 7 models with different storeys i.e 30, 40, 50, 60, 70, 80, 90 (aspect ratio 3.67-10.86) and with fixed plan area. As a part 1 investigation to optimise the diagrid angle a 30 storey Diagrid structure performance is studied with 4 different diagrid angles one storey module angle 35°45’, Two storey module angle 55°13’, Three storey module 65°9’, Four storey module 70°51’. The optimized diagrid angle is used for different aspect ratio high rise structures to investigate the performance in terms of Storey displacement, Storey drift ratio, base shear and time period. For all the models plan area is fixed. Second part of investigation was a numerical study carried out by utilizing identified optimum angle of diagrid is applied on high rise buildings with aspect ratios 3.67, 4.86, 6.06, 7.26, 8.46, 9.67, 10.86 (Aspect ratio is the total height of the building to the width of the building). Behaviour of the Diagrid buildings due to change in aspect ratio is analysed based on parameters such as Storey displacements, Storey drift ratio, Base shear, Time period. As a part of investigation parameters such as Storey displacements and storey drift ratio were evaluated if they were within the limits as per IS code provisions. Percentage increase in storey displacements, maximum storey drift ratio,

Ultra-high-performance concrete: Constituents, mechanical properties, applications and current challenges

Ultra-high-performance concrete (UHPC) is a new class of concrete developed in France in the 1990s with superior characteristics including high workability, high compressive strength, increased ductility, and high resistance to environmental attacks. UHPC is increasingly used in local and international construction markets in the construction of high rise structures, long-span precast/prestressed bridge girders, marine, aviation, and defense construction applications due to its superior mechanical properties, and favorable long-term performance.This study presents recent research findings regarding the UHPC mix designs, fresh and hardened concrete properties, and current UHPC applications in the construction industry including specific bridge applications. Despite of UHPC advantages, multiple impediments are present that delays the widespread of UHPC application in the construction industry including lack of design codes and specifications for estimating UHPC performance, the need for special batching, mixing, and curing.This study assists different construction stakeholders in understanding the unique characteristics, advantages, and impediments to the widespread of UHPC applications. The deciphering of UHPC will help increase its overall market share in local and global construction markets.

A Study of Mechanical Properties of High Strength Concrete

High strength concrete is widely used for construction of high rise structures like bridges and dams so on. But using high strength concrete cost us more. Alternatively we can use some admixtures which can increase strength indirectly. In this project we have used GGBS, MICROSILICA AND ALCCOFINE and CRYSO is 1% in chemical admixture. On conducting different trail mixes we have come to know that by using 0%, 5%,10%,15%,20% and 25% is tested in normal water for 3, 7, 28 days. The results showed the suitability of concrete improvement in strength in normal water. In this paper reports from few researchers have been studied on strength and durability performance of alccofine as a partial replacement of cement in concrete. The efforts made by the researchers for enhancing the performance of concrete over the last few years proved that supplementary cementitious materials with mineral and chemical admixtures can improve the strength and durability of concrete. Alccofine is one among the supplementary cementious materials. Alccofine is new pozzolanic material which is bringing technical revolution in the construction industry. From the survey it is found the alccofine can achieve high strength when is replaced by cement at 0% - 20% compared to the traditional concrete. Micro silica is an amorphous type of silica dust mostly collected in bag house filters as by-product of the silicon and ferro-silicon production. The paper summarizes important physical and chemical properties of micro silica and uses those results for an evaluation of micro silica from a Health Safety and Environment (HSE) standpoint. Micro silica consists of spherical particles with an average particle size of 150 nm and a specific surface area of typically 20 m3/g. The chemical and physical properties of this inorganic product are different as compared to other amorphous and crystalline silica poly morphs. More than 500.000 MT of micro silica are sold to the building industry world-wide and are used in fibre cement, concrete, oil-well drilling, refractories, and even in polymers.

Seismic stability of slopes reinforced with sleeved and unsleeved piles

The development of urban areas in hilly portions of the ground has caused the construction of high rise structures on slopes which sometimes are in a marginal stability. In order to decrease the lateral loads transferred from piles to slopes especially at shallow depths, it is suggested to use of compressible materials such as polystyrene or geofoam as an annulus or sleeve located all-round the outer periphery of concrete piles. The dynamic soil-sleeved pile interaction has not been reported in the literature before. In this paper, 3D finite-difference dynamic analyses using an elastoplastic constitutive model considering dynamic properties of the soil are carried out to study the dynamic soil–pile interaction for both sleeved and unsleeved piles constructed in sloping ground. The effects of sleeve part on stability results, various lengths of piles, various slopes of the ground, various spaces between piles and effects of single or group of piles are investigated. The stability of slopes has been evaluated using a new code based on Strength Reduction Method technique. The variations of shear force and bending moment of piles during dynamic loading have been studied too. Finally, the effective arching distance between piles would be discussed.

Research on Design of Inner-Climbing Tower Crane Supporting System

Safety is essential for tower cranes in construction engineering, as the inner-climbing tower crane is widely used in the construction of high-rise structures, design safety, reliability and support system which can be turnover is an important prerequisite for protecting the safety of construction. By understanding the interrelationships between construction environment of Henglong Plaza Twin Towers in Shenyang city and ZSL2700 tower, the article will analyse the support system for the project. It mainly uses finite element analysis software ANSYS which can create mechanical status of modeling to analyzing the supporting structure. It can guarantee the structures rationality and the security reliability. Project Summary Shenyang municipal government square tower engineering which building height is 350.6m has the underground layer 4 and the ground 70 layer. The office building has used the frame core tube structure system. The outside frame is composed by the square shape section coagulation earth pyramid and the peripheral steel girder. The rectangular core tube was the reinforced concrete, while in the core tube outer wall has established some steel pole. This project adopt two boom tower cranes from Zhongsheng construct machine company (Nanjing).The first number tower crane is ZSL750, which maximum torque is 750tm; the second number tower cranes is ZSL2700. This paper takes the ZSL2700 tower crane as an object, studying this machines stressful condition of attachment system. The ZSL2700 tower cranes most high-torque is 2600tm, pitching arm angle ranges 85-65 .The maximum lifting load is 100t. The biggest hoisting up scope is 55m, which lifting load is 37.6t.When the crane surpasses the permission lifting load or the hoisting up moment of force, PLC can break the power implementation protection automatically. The tower machine need carry on 19 climbs in the construction process. Fig. 1 Two tower crane installation location diagram