人工破拆作业肌肉疲劳分析及预测建模

Manual demolition is one of the primary tasks to demolish concrete-steel constructions. Physical hazardous conditions such as awkward posture, high physical workload, long working time period and vibration from the demolition devices lead to muscular fatigue and even musculoskeletal disorders. Muscular fatigue and its predicting model in manual demolition tasks haven’t been explored. Vibration factor also hasn’t been considered when constructing the muscular fatigue prediction models. The applicability of existing prediction models for manual demolition tasks is highly questionable. Therefore, this research focuses on the muscular fatigue in tasks of manual demolition with hand-held power tools. At first, factors influencing muscular fatigue of manual demolition tasks will be analyzed and simulated manual demolishing experiments will be designed. Objective data, such as force, surface electromyography, vibration and subjective ratings of perceived exertion obtained from simulated demolishing experiment will be used to explore the characteristics and the development of muscular fatigue in static tasks. Also, static prediction models for muscular fatigue considering vibration, working posture and other parameters will be established. Then, based on the static muscular fatigue research results, static units will be divided for dynamic manual demolition tasks and then the muscular fatigue will be analyzed according to force analysis from facet joint.Dynamic muscular fatigue models introducing relevance parameter may be constructed. At last, experiments and theoretical analysis will be carried out to validate and refine our models. The outcomes of this study will provide benefits in optimizing training program, reasonable crew allocation and work schedule in manual demolition missions, releasing the muscular fatigue and reducing the risk of musculoskeletal disorders.

人工破拆是破拆钢筋混凝土结构的重要手段之一。该作业姿势特殊，负荷大，时间长，伴随强烈振动，容易引发作业人员肌肉疲劳，甚至导致肌肉骨骼疾患。现有研究未系统分析人工破拆作业肌肉疲劳，也未构建其预测模型，而现有肌肉疲劳预测模型都未考虑振动因素，以致其对该作业之可适用性高度存疑。针对上述问题，依据人工破拆手持振动工具作业特征分析影响其肌肉疲劳的因素，设计模拟人工破拆作业实验，基于受力、肌电与振动等客观测量数据，以及主观疲劳评分数据，研究静态作业肌肉疲劳特征及发展规律，构建引入振动及姿势等参数的静态肌肉疲劳预测模型；其次，以静态研究为基础，划分工作单元，基于关节层面受力分析研究动态作业肌肉疲劳，构建引入关联参数的动态肌肉疲劳预测模型；最后，对构建的预测模型进行理论与实验验证与修正。研究成果可为人工破拆作业训练改进、现场作业人力配置及作业组织提供指导，缓解作业人员肌肉疲劳，降低肌肉骨骼损伤风险。

人工破拆作业广泛存在于路桥工程、建筑工程、市政工程以及灾后破拆营救活动中，由于作业姿势特殊，负荷大，时间长，伴随强烈振动，容易引发作业人员肌肉疲劳，甚至导致肌肉骨骼系统疾患。本项目关注人工破拆作业活动产生的肌肉疲劳现象，通过实地和问卷调查、实验和仿真等方法和手段，探究作业人员使用不同工具进行不同姿势破拆作业中肌肉疲劳的产生和发展特征并评估其姿势风险，构建了描述肌肉疲劳发展、感知以及恢复的预测方程，并且对破拆活动后作业人员进行的相关人工搬运物料活动而导致的肌肉疲劳也做了相关研究。研究表明：人工破拆作业肌肉疲劳累积明显，肌力下降较快，主观评分上升，一些肌群肌电振幅增大，频率下降；破拆作业人员手部、肩膀、颈和腰部肌肉骨骼疾患风险高；蹲姿作业姿势下腰背风险较高、脊椎受力大且右三角肌前束容易产生肌肉疲劳累积；站姿地面破拆活动中肱二头肌、肱三头肌、胸大肌容易产生肌肉疲劳累积，此时采用手臂伸直且身体前倾姿势施力5kg左右肌肉疲劳累积较慢；壁面破拆活动中，90cm高度破拆时所能坚持时间最短，40cm、90cm和165cm高度破拆主观评分最高，采用5.6kg工具施力20N时肌肉疲劳累积风险较低；40s工作+20s休息作业安排下肌肉疲劳累积较缓慢；破拆后拉物作业、提物作业肌肉疲劳产生明显，拉物作业中拉物3min休息3min时肌肉疲劳累积较慢。基于实验结果，构建了引入高度、负荷等参数的肌肉疲劳、疲劳感知模型以及引入时间参数的肌力恢复以及恢复感知模型。该项目对人工破拆及其相关作业中的肌肉疲劳进行了综合测量，探讨了肌肉疲劳特征和发展规律，为其作业活动减少肌肉疲劳累积与肌肉骨骼损伤预防奠定理论基础。所构建的肌肉疲劳预测模型和恢复模型，充实了现有肌肉疲劳相关模型。研究成果可为人工破拆作业活动作业绩效提升以及相关活动肌肉疲劳减缓以及肌肉骨骼疾患预防提供指导。