Safety and serviceability assessment for high-rise tower crane to turbulent winds

Tower cranes are commonly used facilities for the construction of high-rise structures.To ensure their workability,it is very important to analyze their response and evaluate their condition under extreme conditions.This paper proposes a general scheme for safety and serviceability assessment of high-rise tower crane to turbulent winds based on time domain buffeting response analysis.Spatially correlated wind velocity field at the location of the tower crane was first simulated using an algorithm for generating the time domain samples of a stationary,multivariate stochastic process according to some prescribed spectral density matrix.The buffeting forces applied to the structure were computed according to the above-simulated wind velocity fluctuations and the lift,drag,and moment coefficients obtained from a CFD computation.Those spatially correlated loads were then fed into a well calibrated finite element model and the nonlinear time history analysis was conducted to compute structural buffeting response.Compared with structural onsite response measurement,the computed response using the proposed method has good precision.The proposed method is then adopted for analyzing the buffeting response of an in-use tower crane under the design wind speed and the maximum operational wind speed for safety and serviceability assessment.

Evaluation of Driver-Induced Human Errors in Smart Construction Tower Crane Operations Based on DEMATEL-ISM-MICMAC

With the advent of Industry 4.0, smart construction sites have seen significant development in China. However, accidents involving digitized tower cranes continue to be a persistent issue. Among the contributing factors, human unsafe behavior stands out as a primary cause for these incidents. This study aims to assess the human reliability of tower crane operations on smart construction sites. To proactively enhance safety measures, the research employs text mining techniques (TF-IDF-Truncated SVD-Complement NB) to identify patterns of human errors among tower crane operators. Building upon the SHEL model, the study categorizes behavioral factors affecting human reliability in the man-machine interface, leading to the establishment of the Performance Shaping Factors (PSFs) system. Furthermore, the research constructs an error impact indicator system for the intelligent construction site tower crane operator interface. Using the DEMATEL method, it analyzes the significance of various factors influencing human errors in tower crane operations. Additionally, the ISM-MICMAC method is applied to unveil the hierarchical relationships and driving-dependent connections among these influencing factors. The findings indicate that personal state, operating procedures, and physical environment directly impact human errors, while personal capability, technological environment, and one fundamental organizational management factor contribute indirectly. .

An Intelligent System for Real-Time Condition Monitoring of Tower Cranes

Reliability and safety are major issues in tower crane applications. A new adaptive neurofuzzy system is developed in this work for real-time health condition monitoring of tower cranes, especially for hoist gearboxes. Vibration signals are measured using a wireless smart sensor system. Fault detection is performed gear-by-gear in the gearbox. A new diagnostic classifier is proposed to integrate strengths of several signal processing techniques for fault detection. A hybrid machine learning method is proposed to facilitate implementation and improve training convergence. The effectiveness of the developed monitoring system is verified by experimental tests.

Research on the Three-dimensional Modeling and Optimization of a Virtual Tower Crane Based on 3DS Max, Solidworks and EON Professional

Three-dimensional modeling of virtual hoisting machinery is the critical works to structure the system of virtual construction, and the foundation to realize intelligent and interactive virtual hoisting. Aimed at enhancing the requests of image quality and stability of the virtual construction scene, taking a tower crane for example. We studied the technology of three-dimensional modeling and optimization of a virtual tower crane, and a method named two-stage model optimization was put forward. This depended on the modeling stage using Solidworks and 3DS Max and the performance optimization stage in EON. The practice of software development indicates that the proposed methods of three-dimensional modeling and optimization could satisfy the performance request of virtual construction system and be popularized to other virtual system.

Importance Ranking of Accident Factors of Construction Tower Crane by AHP Technique

In Korea construction industry, the increase of tower crane’s usage continuously and the accidents of tower crane are increasing simultaneously. But research on tower crane is insufficient for reducing the tower crane accident. This study aims to derive the importance ranking of accident factors of cab-control tower crane by AHP analysis. AHP survey was conducted on experts such as construction engineer, construction manager, safety engineer, and tower crane operator, who have more than 10-year career. The results of AHP analysis reveal that top ranking factor of cab-control tower crane’s accident is erection work. Therefore, the derived factors should be managed, and the priority measures taken for reducing the tower crane accidents according to the ranking of accident factors.

New Technology of Installing the Attached Self-Climbing Tower Steel Gantry Cranes

The Liujiaxia Bridge is 536 m span steel truss stiffening Girder Bridge, tower with double-column steel concrete slructure, which is the world＇s largest diameter, the largest steel plate thickness of concrete pylon. Sarasota manufactured using standard pipe segment, group fight scene segment piecewise hoisting tower segment perfusion within the micro-expansion concrete construction technology, tower maximum height of 61.5 meters. This paper describes a piecewise Sarasota steel installation, piecewise perfusion within the micro-expansion concrete tower new construction method - attached to a self-climbing tower bridge ganlry crane mounted pylon construction technology of large steel components. Of the ＂entity attached to the pylon installation of equipment by section climb＂ design, composition and construction applications are described in detail.

Tower crane path planning based on improved ant colony algorithm

In order to solve the problem of path planning of tower cranes,an improved ant colony algorithm was proposed.Firstly,the tower crane was simplified into a three-degree-of-freedom mechanical arm,and the D-H motion model was established to solve the forward and inverse kinematic equations.Secondly,the traditional ant colony algorithm was improved.The heuristic function was improved by introducing the distance between the optional nodes and the target point into the function.Then the transition probability was improved by introducing the security factor of surrounding points into the transition probability.In addition,the local path chunking strategy was used to optimize the local multi-inflection path and reduce the local redundant inflection points.Finally,according to the position of the hook,the kinematic inversion of the tower crane was carried out,and the variables of each joint were obtained.More specifically,compared with the traditional ant colony algorithm,the simulation results showed that improved ant colony algorithm converged faster,shortened the optimal path length,and optimized the path quality in the simple and complex environment.

虚拟化教学试验平台在 Crane CAI 中的应用尝试

试把虚拟仪器技术应用于ＣＡＩ开发，探讨了研究虚拟化教学试验平台的意义，结合工程起重机教学，研制了塔式起重机动载影响系数动力反应模拟试验演示台，并给出了其建立的方法和过程。

超高层建筑工程内爬塔式起重机附着提升拆除关键技术

内爬塔式起重机是适用于超高层建筑的一种大型设备,本研究介绍了内爬塔结构系统构造及爬升流程,通过设置支撑梁承受结构重力和塔式起重机设计荷载、设置液压油缸和内爬框架进行顶升操作,完成内爬塔结构提升。以小塔拆大塔为塔式起重机拆除原则,设计了两次屋面吊拆除过程,保障拆除工期和屋面结构安全。建立了支撑梁和内爬框架的三维实体有限元计算模型,优化支撑梁系统设计,得到了支撑梁和内爬框架在满载支撑状态下的应力和位移计算结果。结果表明,支撑系统安全可靠。

Research on ETABS Steel Tower atop Building Structural System

Equipping steel tower atop building structural system at the top of high-rise buildings is applied increasingly. However, the earthquake disasters indicate that under seismic effect, the tower on the roof reacts strongly to the earthquake, and the gazebo is damaged greatly under the condition that major structure has no earthquake damage. Based on analyzing the characteristics and application methods of ETABS software, for engineering projects, the paper uses ETABS software and simplified calculation method to calculate and make comparison analysis on steel tower atop building structure. The analysis results indicate that the method established in the paper has higher accuracy, which can meet the engineering requirements.

Intelligent virtualization of crane lifting using laser scanning technology

Background This paper presents an intelligent path planner for lifting tasks by tower cranes in highly complex environments,such as old industrial plants that were built many decades ago and sites used as tentative storage spaces.Generally,these environments do not have workable digital models and 3 D representations are impractical.Methods The current investigation introduces the use of cutting edge laser scanning technology to convert real environments into virtualized versions of the construction sites or plants in the form of point clouds.The challenge is in dealing with the large point cloud datasets from the multiple scans needed to produce a complete virtualized model.The tower crane is also virtualized for the purpose of path planning.A parallelized genetic algorithm is employed to achieve intelligent path planning for the lifting task performed by tower cranes in complicated environments taking advantage of graphics processing unit technology,which has high computing performance yet low cost.Results Optimal lifting paths are generate d in several seconds.

风荷载作用下塔式起重机结构的随机振动分析

对塔式起重机的研究一般是将风荷载进行应力等效或者是流体分析,而本文将结合脉动风的随机特性与Ansys的随机振动模块进行分析。首先计算塔机在非工作状况下的预应力模态,确定其固有频率及振型;其次基于Davenport风速谱计算出随机振动模块所需的PSD数据;最后从后处理模块中得到所需的数值。

基于STM32的塔机数据采集和监控系统设计

针对塔机作业对运行状态参数和作业环境实时监测的需求,设计了一种基于STM32的塔机数据采集和监控系统。该系统采用STM32F103RCT6为核心的微处理器对塔机运行各项状态参数结合传感器进行数据采集和处理,传感器信号经带数字隔离的A/D转换模块和RS485转TTL模块传输到微处理器,微处理器通过串口转以太网模块将采集的传感器数据发送到由工业交换机和网络摄像机组建的局域网中。最后,采用Java语言结合Spring Boot框架开发系统上位机页面对传感器数据和视频监控画面进行显示。通过测试,该系统能够对塔机运行状态参数和塔机作业环境进行实时监测,传感器采集数据的平均相对误差为0.74%,摄像机监控画面平均延时20.4 ms,实现了数据高速准确的实时监测,满足了监测塔机的系统需求。

塔吊基础、附墙杆和预埋件分类和安装方法

当塔吊超过独立高度后,为保证塔身整体稳定性,需将塔吊依附于建筑物进行锚固约束,因此,附着位置的可靠连接显得尤为重要。论文主要介绍了塔吊基础的分类和安装工艺流程,以及塔吊附着安装工艺流程,总结了3种附墙杆的特点和安装工法,以及附墙埋件的分类和安装工法。

基于节段模型测力方法的塔式起重机风荷载特性研究

塔式起重机被广泛应用于铁道工程和土木工程施工过程,属于高耸结构体系,风荷载是塔式起重机结构设计的控制性荷载。为完善《塔式起重机设计规范》(GB/T 13752—2017)和《建筑结构荷载规范》(GB 50009—2012)中的塔式起重机斜风向设计风荷载计算方法,解决风向、吊臂、平衡臂位置等因素对塔式起重机遮挡和干扰引起的设计风荷载计算问题。选取平头塔式起重机为研究对象,对塔身、吊臂、平衡臂进行多工况的节段模型测力风洞试验,研究湍流强度、节段干扰和遮挡等因素对塔式起重机节段风荷载特性的影响规律,研究不同风向下节段阻力系数分布规律,对比标准化阻力系数与当前主要规范的异同,进而探讨节段斜风向标准化阻力系数计算方法。研究结果表明湍流强度对节段阻力系数影响较小,可忽略,而平衡臂和吊臂相邻节段的干扰会减小测试节段的阻力系数;在斜风向下,由于吊臂和平衡臂之间存在相邻节段干扰,国内外规范方法的计算值均会大于干扰工况的节段风洞试验值;当前主要国家规范规定的垂直风向塔身、吊臂、平衡臂阻力系数与风洞试验测得的阻力系数值较为接近,基于风洞试验结果给出典型风向的塔式起重机各节段的风荷载系数取值可用于结构设计;基于风洞试验测试结果推导的塔式起重机斜风向风荷载计算方法具有较好的拟合效果。研究成果可推荐相关工程应用,可为相关规范的修改或补充提供参考。

塔式起重机相关知识与使用管理

介绍了塔式起重机的相关知识,包括电力驱动特点、供电电缆、配电箱与隔离开关、供电制及漏电保护器、润滑材料及选用原则、稳定性计算等,总结了塔式起重机的操作规程、技术管理要点及安装程序。

塔式起重机附着装置相关要求说明及临时锚固正确方法的探讨

介绍了塔式起重机附墙的基本作用和相关名词的解释,阐述了附着装置的设计标准,通过模型演算塔式起重机临时锚固时吊臂的受力状况,并通过演算结果得出正确的锚固方法,以指导塔式起重机采取正确合适的锚固措施。

装配式混凝土建筑施工现场群塔布置的影响因素分析

装配式混凝土建筑的预制构件类型繁多、数量大,现场吊装作业任务量大。装配式混凝土建筑施工现场进行群塔布置时需要考虑塔吊的选型、施工场地和道路情况、塔吊的站位和群塔作业防碰撞要求等因素。在保证群塔施工中相互运行安全的前提下,群塔的合理布置应可最大限度地提高群塔利用效率,满足施工要求。

密度峰值聚类在塔机损伤诊断中的应用研究

建立塔机有限元模型,获取塔机完好状态和各损伤工况的各采集点的动态位移。提出了两种模型建立方法,基于悬臂梁的双输入单输出模型和基于时域数据的动态双输入单输出模型,对基于时域数据的双输入单输出模型首先利用最小二乘法计算参数初值,进一步利用粒子群优化方法进行参数优化,提高了模型精度。以完好工况的塔机数据为基础,建立基于悬臂梁的双输入单输出模型和基于时域数据的双输入单输出模型,计算参数,建立损伤识别模型,用待检状态的位移数值拟合模型,用两种模型计算出的残差方差做损伤因子,利用密度峰值聚类方法对损伤因子进行分析,实现了对塔机的损伤判定和损伤位置的确定。这种基于密度峰值聚类的诊断方法可对塔机微小损伤进行智能诊断和位置确定,该方法只需要塔机完好状态的数据和待检状态的数据即可自动诊断,解决了塔机损伤识别中损伤数据难以获取,因而无法实现智能训练和诊断的问题。

采用WSR方法论的塔吊坍塌事故安全评价方法

为提高塔吊安全管理效率,采用物理-事理-人理(WSR)方法论构建塔吊坍塌事故安全评价体系。从物理层面基于塔吊的结构组成视角分析塔吊坍塌的主要风险致因;从事理层面梳理塔吊坍塌事故发生的内在机理,并建立塔吊坍塌事故树模型;从人理层面提出塔吊坍塌关键风险因素的应对措施;通过实例论证安全评价模型的可行性。研究结果表明:保护装置失效是塔吊坍塌事故树模型中最关键的风险因素,其关键重要度为51.14%,加强塔吊设备安全隐患巡查、规范塔吊作业人员行为和优化塔吊运行安全监管能有效降低人不良思想和行为造成的物理风险。