隧道震裂岩体围岩分级方法初探

汶川地震产生了大量的震裂松动山体,为合理评价在这些震裂山体中新建隧道的围岩级别,通过极震区在建隧道现场震裂岩体调查,对震裂岩体特征及其对围岩稳定性的影响进行了分析。震裂岩体是一种受强烈地震波作用后,岩体结构面更加发育,层间结合更差的一种岩体;并且硬质岩和软质岩的震裂特征不同,硬质震裂岩体易产生集中式张裂缝和松动,软质震裂岩体易产生体积式松弛变形。在此基础上,提出了岩体震裂等级,划分为轻微、中等、强烈三种级别,并建立了震裂岩体围岩分级的修正方案,即:轻微震裂岩体对围岩稳定性影响不大,可不考虑降低围岩级别,或者降低0.5级;中等震裂岩体对围岩稳定性有不利影响,围岩级别降低0.5～1级;强烈震裂岩体对围岩稳定性影响极为不利,围岩级别降低1～1.5级。     

内河营运船舶应用天然气项目温室气体 自愿减排方法学研究

内河营运船舶应用天然气可以有效的降低我国温室气体的排放,文章以内河营运船舶应用天然气项目温室气体自愿减排方法学为研究对象,以重庆某船务公司项目为例,运用该CCER方法学对内河营运船舶应用天然气项目的碳减排量进行了详细的计算,表明本文提出的方法具有实际可操作性.     

Application of BIM Technology in the Construction Management of a Metro Station北大核心CSCD

For the restricted construction site of a Beijing metro station surrounded by many important buildings and characterized by complex staggered underground pipelines, many construction difficulties and a high level of re-quired management, settlement monitoring is necessary for the sake of construction safety. A 3D model of the metro,a model of the specially shaped structure and models of many details of the metro were established using the BIM technique, allowing for: creation of a 3D presentation, extraction of construction quantities, construction conse-quence optimization, guidance of construction endeavors, simulation of the construction process, 4D dynamic con-struction management and 4D dynamic settlement monitoring. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

Axial Response of a Compression Pile to Nearby Excavation北大核心CSCD

One of the major concern in the excavation in soft soil areas is the effect of soil movement on adjacent pile foundations. In this paper, three-dimensional finite element models are established to study the axial response of the adjacent pile foundations close to an excavation in soft soil. The results show that, due to the nearby excavation, the axial bearing capacity of a single pile under compression decreases about 13.6%, and considerable additional settlements of a single pile subjected to the working compression load are generated. Therefore, the characteristics of load transfer mechanism between pile shaft and around soil, as well as the tip soil reaction are investigated extensively, which demonstrates that, as expected, the nearby excavation leads to a reduction of ultimate soil friction resistance. Furtherly, the widely employed load transfer method for pile foundation is modified to consider the effects of nearby excavation, which can be employed to predict the axial response of an axially loaded pile foundation beside an excavation. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

基于非线性模型的发动机非稳态工况控制

针对发动机非稳态工况,建立了非线性模型.设计了滑模控制器和PID控制器分别对节气门开度和点火时刻进行自适应调节.对发动机怠速工况进行仿真的结果表明,发动机转速波动幅值低于6 r/min,表明所建的非线性模型适合于发动机非稳态工况控制.     

杭州市运河二通道桥大截面钢箱拱合理断面设计研究

全焊钢箱拱在桥梁设计的应用中,通常采用密布横向隔板并配合纵向加劲来保证钢箱拱截面的局部稳定性,但随着跨度的增加,钢箱拱截面尺寸的放大,对横向隔板的刚度需求也不断增加,传统的空腹式横向隔板的用钢量显著增加,进而影响到整个拱的经济性。针对这个问题,在大截面钢箱拱的断面布置上,对空腹式隔板、框桁混合型隔板以及增设中间纵隔板几个方案进行受力性能、构造、经济上的比较,可为以后大截面钢箱拱的设计提供参考。     

CATIA电气布线在摩托车上的应用

CATIA三维线束设计与机械设计模块参数化关联,在进行三维布线后可生成完整的数字化样机,该数字化样机不仅包括结构件、电器元件的布置,还包括线束的进出线方式、线束在车体内的走向、线束的选型及绑扎方式等,设计人员可以在数字化样机上进行设计思路交流,及时发现问题、及时对设计中存在的缺陷进行更正,大大缩短了开发周期。     

温拌胶粉改性沥青高温性能研究

为系统研究胶粉细度、胶粉掺量以及拌合温度对温拌胶粉改性沥青高温性能的影响效果及规律,通过采用流变学原理,以胶粉细度、胶粉掺量、温拌剂掺量设计三因素三水平正交试验,进行动态剪切流变试验(DSR),以车辙因子为评价指标,确定温拌胶粉改性沥青的高温性能影响规律。结果表明:胶粉掺量是最主要影响因素,依次是胶粉细度和温拌剂掺量;胶粉改性沥青的高温性能随胶粉细度的增大而降低,随胶粉掺量和温拌剂掺量的增大而升高,当胶粉掺量达到17.5%,温拌剂掺量达到3%时,温拌胶粉改性沥青的高温性能提高效果已不明显。     

一种新型HEV动力耦合器的ADAMS建模与仿真研究

动力耦合器是混合动力汽车的核心部件,对动力耦合器进行相关控制就可以实现混合动力车辆不同模式之间的转换。运用ADAMS仿真软件,对一新型动力耦合器(即汽车上常用差速器的反用)各项功能进行了仿真。仿真结果表明,该新型动力耦合器可以很好地实现预期目标,并得出了相关的运动学与动力学关系式。最后,通过台架试验验证了仿真结果的正确性。     

基于城市交通特征的公交车辆动力传动系统参数的合理匹配

针对城市公交车辆的行驶特点,提出将5循环工况百公里燃油消耗量作为经济性评价指标,将加权驱动功率损失率作为动力性评价指标来评价其动力传动系统的匹配。利用MATLAB软件编制了一套计算程序,对某城市公交车辆动力传动系统参数进行了合理的匹配。计算结果表明,所提出的评价指标能更好地表征城市公交车辆的特性,与实际使用情况更接近。