A Study on Factors Influencing Cost Overrun in High-rise Building Construction across India

Cost overrun is a common problem in construction projects worldwide.Most Indian construction projects,particularly those involving high-rise buildings,have had severe cost overruns.For managers,architects,engineers,and contractors,completing building projects within the specified cost budget has become the most important and hard assignment.Since it is common for high-rise building projects to go over budget,the aim of this study is to find out the causes of cost overruns and provide effective measures.The study found 70 cost overrun factors based on a comprehensive literature review and expert opinions.A Google form questionnaire was distributed to 150 construction professionals across India.After following up,101 of the 150 responses were received.A five-point Likert scale was used and the acquired data was analyzed and ranked using the Relative Importance Index(RII)technique.According to the findings of RII,the top ten critical factors influencing cost overruns were frequent change orders during construction by the owner,delay in construction,escalation of material prices,market inflation or deflation,rework,frequent changes in design,inaccurate evaluation of the project timeline,unforeseen ground condition,inaccurate quantity take-off,and delay in progressive payment by the owner.Spearman’s rank correlation test revealed that there is a very significant relationship between the rankings of factors provided by the owner,the consultant,and the contractor.In addition,a factor analysis tool in the SPSS software was also used to categorize the seventy factors into sixteen core components.The top ten critical factors were presented to subject matter experts,and their suggestions were being compiled.These results are expected to help construction professionals minimize cost overruns,improve cost control measures,and initiate future research.

Transient dynamic analysis and comparison on wedging processes of overrunning clutches with different contact surfaces

The effects of contact surface on dynamic wedging behavior of the roller and inner-ring of the overrunning clutch in a dual-turbine torque converter were investigated to reveal the friction self-locking mechanism and dynamic process.Planar strain clutch models including roller,inner-ring and outer-ring were built,and transient wedging process was analyzed with an explicit dynamics method.The modeling of stress and strain distribution and variation of two kinds of contact surfaces show that there are three stages named slipping,wedging and binding respectively during whole wedging process.Meanwhile the geometric structures of contact surfaces greatly influence the peak stress and strain distribution of the wedging process of the roller and inner-ring.The load bearing performance of contact surfaces with logarithmic spiral curve is better than that with straight line.Our study provides theoretical foundation for design and further optimization of wedging contact surface of an overrunning clutch in a dual-turbine hydrodynamic torque converter.

Effect of Camel Milk Fortified with Dates in Ice Cream Manufacture on Viscosity, Overrun, and Rheological Properties during Storage Period

The effect of using camel milk with 2 dates types (Sokary & Al-Khalas), in 3 forms (paste, pieces, and molasses), with 2 different concentrations (5% & 10%) in the manufacturing of ice cream on its viscosity, overrun%, rheological and melting properties during storage period up to 60 days at -18&#176C was studied. It was noticed that there are higher mean of viscosity values (cp) when using “Al-khalas” dates paste 5% and 10% followed by samples with “sokary” paste then samples with molasses in ice cream samples compared to those with added date’s pieces of either “Sokary” or “Al-khalas”. There are significant differences of overrun values between all treatments and samples with the added date paste of either “sokary” or “Al-khalas” which recorded the lowest values. Increased melting resistance and good qualities as heat shock and melting properties were significantly better for the samples with added dates pieces or paste unlike the molasses. The storage effect is obvious decline, especially when using dates molasses.

Study of Factors Causing Time and Cost Overrun in Pre-Construction Project (A Case Study of Malaysia)

Cost and time overrun are the key troubles of any improvement ventures. These troubles are inflicting the terrible end result in the development of kingdom monetary improvement and thriving. To overcome these problems, the?paper examines predominant impact on elements causing the mission postponement and cost. A poll review was led for the situation study embracing various information-gathering procedures. The discoveries from the contextual investigation uncovered that the most persuasive factors in Malaysia:?1) contractor’s inappropriate arranging, 2) poor site the board, 3) deficient contractual worker experience,?are the most powerful factors. This paper has likewise broken down the normal and least effective of the postpone variables causing task deferral and cost overrun in Malaysia. It likewise infers that there are various measures as per the idea of deferring components to decrease the effect on task postponement and cost overruns in the development industry.?There are significant factors in the control of time overrun that would be actual thought related to know and tackle in great impact to improvement rate which may additionally no capacity that be recovered. Thirty (30) massive development extensions in Malaysia were exceptional coping with time overrun at some stage in development. Out of 30 undertakings, 17 (56.67%) ventures had been introduced by using 1100 days’ time overrun, 5 (16.67%) extensions in the middle of a hundred and one to 200 days, 5 (16.67%) ventures?201 to 300 days while three (10%) ventures have been deferred for timeframe over 300 days.

Research on Cost Overrun Risk of Construction Phase of Vietnam Highway International Contracting Project

Recently, the highway construction projects increase rapidly in Vietnam and most of them are international contracting projects. It results serious negative influence on the local government and enterprises that the common cost overrun of projects, and the risk factors of it is different in the different countries, different stages and projects types. So in this paper, we generate an evaluation index system of highway construction projects cost overrun risk in Vietnam in the perspective of different project participants, and also evaluate the effects of these factors in method of regression analysis. The empirical results confirmed 7 main factors that have aggravated cost overrun risk in construction stages, e.g. survey and design scheme risk. In final, the corresponding suggestions are proposed to reduce the project cost overrun risk.

Application of predictive control scheduling method to real-time periodic control tasks overrun

Based on the abort strategy of fixed periods, a novel predictive control scheduling methodology was proposed to efficiently solve overrun problems. By applying the latest control value in the prediction sequences to the control objective, the new strategy was expected to optimize the control system for better performance and yet guarantee the schedulability of all tasks under overrun. The schedulability of the real-time systems with p-period overruns was analyzed, and the corresponding stability criteria was given as well. The simulation results show that the new approach can improve the performance of control system compared to that of conventional abort strategy, it can reduce the overshoot and adjust time as well as ensure the schedulability and stability.

斜撑离合器环形弹簧径向刚度计算

斜撑离合器在机械领域及航空动力系统起着重要作用,弹簧的径向刚度是影响斜撑离合器脱开转速和楔合性能的重要指标。斜撑离合器弹簧的径向刚度尚无可靠的计算方法,因此将弹簧等效为圆环,推导出弹簧径向刚度的理论计算方法,并通过仿真和试验验证了理论计算的正确性。

天山中段2次6级地震前钻孔应变高频异常分析

2014年以来,天山中段分量钻孔应变仪空前增多,这些高采样率的应变观测资料蕴含着丰富的构造信息。如何从高采样率观测资料中提取有效的前兆异常信息,是分析研究人员亟待解决的问题。文章通过对天山中段分量钻孔应变观测数据进行S变换和超限率分析发现,在天山中段2次6级地震前有5套应变资料出现高频信息异常。这些异常均在震前出现,随后达到峰值,临震前或地震后衰减,其中短周期异常信号主要集中在10~720 min频段,且S变换与超限率分析结果具有很好的同步性。结合精河地震震源区及附近的GPS分析结果,发现高频异常信息的分布与该地区地壳运动场具有很好的一致性,进一步验证了高频信息异常的可信度。

高速斜撑超越离合器楔合动态响应研究

针对斜撑式超越离合器高速楔合容易产生故障的实际情况,对其楔合动态过程进行研究。工作过程中,斜撑式超越离合器内部楔块之间、楔块与内外环间以及各部件同保持架间存在碰撞。首先基于Hertz接触理论,求解了碰撞刚度,为明确各参数对高速斜撑超越离合器动态响应的影响程度,建立了包括楔合延迟时间、冲击力矩、最大转速差等在内的评价指标。同时,将高速斜撑超越离合器的楔合动态过程进行划分,以研究几何参数对不同响应阶段的影响。最后,开展了楔块与内环的摩擦条件、弹簧力、碰撞刚度、阻尼和负载等对高速斜撑超越离合器楔合动态响应的研究。结果表明,不同参数对所定义的评价指标的影响程度不同,极端情况下可导致楔合失败。该研究可为工程实践提供一定的理论参考和指导。

SINAMICS SL150磁通调节器输出超限分析与处理

本文结合日照钢铁控股集团有限公司1580mm热连轧精轧主传动系统升级改造之后出现的磁通调节器输出超限进行分析,提出解决方案,为今后出现类似的故障处理提供参考。

现代奥运会场馆治理的历史进程、多重困境与消解之道

奥运场馆的超大规模与巨额成本使奥运会的举办频遭诟病。运用文献资料、逻辑分析等方法,对百年奥运场馆数量波动上涨、使用更新优化、布局模式转换、配套迭代升级的状况及致因进行解析,认为场馆规划有失致使额外成本攀升,场馆利用不佳导致场馆荒废闲置频现,办奥挤出效应招致反对浪潮频发,场馆治理不当引致生态破坏屡现,据此提出若干消解策略:超前规划场馆,规避奥运场馆赛后“白象化”;注重赛后利用,促进奥运场馆发展可持续;倡导节俭办赛,探索场馆多元利用新举措;注重低碳环保,追求场馆治理环境正影响。

基于Apriori算法的飞机冲偏出跑道诱因挖掘

为加强民航客机飞行运行全过程的安全管理,减少飞机起降阶段冲偏出跑道事件发生的概率,对冲偏出跑道事件中的诱发因素进行定性和定量分析,根据事故事件特点,建立起降阶段飞机冲偏出跑道事件诱因分析体系,对不同类型的事件进行布尔离散化,采用Apriori算法对飞机冲偏出跑道数据集开展关联分析,挖掘出不同诱发因素之间的关联规则。以国内某航空公司波音737机队在2001-2021年间冲偏出跑道数据进行分类和识别;运用Apriori算法建立数据挖掘仿真模型;使用MATLAB编程迭代计算,找到飞机冲偏出跑道诱因中有强关联的因素,并保留其数据。结果表明,当飞机故障时,有28.77%的概率会出现飞行员操作有误;当道面积雪时,有23.64%的概率会出现违反标准操作程序;当飞行程序设计不合理时,有22.84%的概率会出现飞行员判断有误;当飞机故障时,有20.65%的概率会出现飞行员控制有误;当跑道道面湿滑时,有20.12%的概率会出现飞行员控制有误。

某三甲专科医院DRG超支病例住院费用结构研究

目的:通过分析天津市某三甲专科医院DRG超支病例的费用构成及其变化规律,旨在为医院费用结构优化、管理效率提升及成本控制提供依据。方法:研究对象为2023年该医院DRG超支金额排名前15的病组,采用结构变动度法分析费用影响因素,并通过灰色关联分析评估各费用分项与总费用的关联度。结果:从7840例病例中筛选出2822例DRG超支病例(占35.99%),主要超支集中在RG13、ES31、HR11、EX23、EX21组。费用主要包括药品费、影像检查费、化验费和治疗费,且这些费用分项在超支与正常病例间存在结构差异,对住院费用的影响各不相同。灰色关联分析揭示影像检查费、化验费在11个DRG组中与总费用关联最强,药品费在3个组中关联最强,床位费在1个组中关联最强。结论:通过调整影像检查费、化验费、药品费和治疗费,可以有效控制医院成本,减少患者住院费用,优化医保基金利用,实现医院、患者和医保基金的共赢。

基于AP-WOA-GRU的分布式光伏集群电压越限动态预测

针对整县光伏背景下规模化分布式光伏接入配电网导致的电压波动问题,提出了一种基于近邻传播聚类(affinity propagation,AP)与鲸鱼算法(whale optimization algorithm,WOA)优化门控循环单元(gated recurrent unit,GRU)的分布式光伏集群电压越限预测方法。首先,在考虑分布式光伏地理坐标气象特征的基础上,添加基于配电网节点负荷密度因素的位置特征,采用近邻传播聚类方法,在不指定聚类数目的情况下划分具有近似气象特征和地理位置特征的分布式光伏集群,提高模型训练效果及适应性;然后,采用鲸鱼优化算法全局搜索GRU模型的最优训练参数,进一步提高模型的训练速度和预测精度;最后,利用WOA-GRU组合模型实现配电网节点电压与环境温度、光照强度的关联匹配,进而实现区域配电网电压波动及电压越限情况的整体预测。实验证明:所提出的方法能够有效提高预测精度及训练速度,强化预测模型的适应能力,具有较好的经济性和实用性。

超高层建筑施工全过程监测技术研究

结合工程实际,针对超高层建筑高度超限、体形不规则、受力及施工复杂而导致的施工难点,从保障工程质量和结构安全的角度考虑,对施工全过程进行了自动化监测。研究分析了工程施工全过程的监测内容、技术方法和监测结果等,总结的监测技术方法及相关工程经验可为类似工程提供参考。

基于高压旋喷桩的超限深危基坑加固技术优化与应用效果

为提高超限深危基坑材料修复加固的效果,提出基于变形监测的超限深危基坑材料修复加固措施研究。在变形监测数据的基础上,以高压旋喷桩技术进行基坑修复加固。通过进行施工准备、桩位放样、钻机就位及钻孔、灰浆制作、旋喷和复搅、冲洗及移动设备等一系列步骤完成高压旋喷桩技术对于超限深危基坑的修复加固。结果表明,采用所提方法深基坑沉降变形小,在降雨较少的春季,其沉降值在0.24 cm以下;在降雨较多的秋季,其沉降值在0.90 cm以下,均严格控制在规定值以内。所提方法可满足超限深危基坑加固工程施工处理需要,能有效完成对基坑的修复加固处理,提高基坑加固工程质量,为基坑加固提供可靠价值参考。