碳达峰目标下中国绿色建造技术驱动因素的作用机制：基于系统动力学仿真分析

绿色建造技术的推广与应用是促进建筑业持续健康发展的根本路径之一,为有效解决目前我国绿色建造技术推广与应用遇到的障碍,在研究国内外相关主要研究成果的基础上,总结归纳影响绿色建造技术发展的因素,并从市场、经济、生态以及社会参与度等角度得到关键驱动因素,据此构建系统动力学仿真模型,对有关驱动因素进行灵敏度的动态分析并观察各主要因素的影响效果,得到碳达峰目标下我国绿色建造技术驱动因素的作用机制。结果表明：各驱动因素对我国绿色建造技术的推广与应用具有正向的促进作用,但影响程度不同,技术研发程度、政策法律完善程度、绿色建造管理模式、节水节地技术效率对成本影响明显,而对生态价值和生产力效率影响不同。根据研究结论,从绿色建造政策法规、技术研发、管理模式和技术效率等方面提出相关对策建议。     

Three-step damage identification method based on dynamic characteristics

A three-step damage identification method based on dynamic characteristics is proposed to improve the structure reliability and security and avoid serious accident. In the proposed method, the frequency and difference of modal curvature （DMC） are used as damage indexes. Firstly, the detection of the occurrence of damage is addressed by the frequency or the square of frequency change. Then the damage location inside the structure is measured by the DMC. Finally, with the stiffness reduction rate as a damage factor, the amount of damage is estimated by the optimization algorithm. The three-step damage identification method has been validated by conducting the simulation on a cantilever beam and the shaking table test on a submerged bridge. The results show that the method proposed in this paper can effectively solve the damage identification problem in theory and engineering practice.     

Shaking table test of pile-water-pier superstructure

The model test of seismic simulation shaking table is an important method to study the seismic design of bridge structure. In order to evaluate the seismic response and dynamic characteristics of pile-water-pier system for developing more reliable design procedures, shaking table model tests of a submerged bridge pier system, including pile groups-cap-pier and inertia mass, were conducted. Since different similitude laws corresponding to different test objectives affected the validity of test results, the similitude law with the aim to consider the effect of hydrodynamic pressure was proposed and confirmed through an actual example. Based on the test results, the effect of water around model on seismic response under seismic excitation input was analyzed and the failure level was judged by observing the variation of basic frequency. The test results indicate that the transfer function of analytical model with water is different from that without water, the natural frequency without water is always higher than that with water, and the first modal shapes are various. It is also concluded that the similitude law is suitable for practical application and the dynamic characteristics and seismic response of the structure system can be changed because of the existence of the surrounding water, which should be paid much attention in the further investigation.