摘要：An optimal design method for two materials based on small amplitude homogenization is presented. The method allows to use quite general objective functions at the price that the two materials should have small contrasts in their relevant physical parameters. The following two applications are shown: Stress constrained compliance minimization and defect location in elastic bodies.

摘要：A case study of seismic response of an earth embankment foundation on liquefiable soils in Kansai area,western Japan was presented. Based on a calibrated cyclic elasto-plastic constitutive model for liquefiable sand and Biot dynamic coupled theory,the seismic analysis was carried out by using a dynamic effective stress finite element method under plane strain condition. A recent design study was illustrated in detail for a river earth embankment subjected to seismic excitation on the saturated deposits with liquefiable sands. Simulated results of the embankment foundation during liquefaction were obtained for acceleration,displacement,and excess pore water pressures,which were considered to yield useful results for earthquake geotechnical design. The results show that the foundation soil reaches a fully liquefied state with high excess pore pressure ratios approaching to 1.0 due to the earthquake shaking. At the end of the earthquake,the extensive liquefaction causes about 1.0 m lateral spreading at the toe and 60 cm settlement at the crest of the earth embankment.

摘要：在隧道项目中,隧道掘进机(TBM)能否顺利施工取决于TBM系统所有部件(从刀具到后备系统)能否正常运转,并取决于全部机车车辆的配合。而在整个TBM系统中,刀盘是影响TBM施工效率最为关键的因素。刀盘的设计影响到掘削效率、刀盘平衡、刀具使用寿命、主轴承/齿轮箱维护、出渣效果、面刀和边刀/排渣铲斗的磨损情况。总体来说,刀盘设计对掘进速度(ROP)、机器利用率(U)及每日进尺(AR)有重要影响。尽管当前可用文献中已就盘形滚刀、切削力、刀盘的某些设计特征做了讨论,但与本论题相关的文献却十分有限,这是因为刀盘的设计主要由隧道掘进机制造商负责,大部分设计工艺都属制造商专有,虽然本论题当前大受关注,但岩石隧道掘进机的设计对终端客户而言仍是个谜题。本文将试着阐明设计中的基本概念,虽不足以帮助读者进行成熟设计,却可助工程师与承包商理解设计步骤中的构思过程、合理设计中应注意的事项以及刀盘设计对于隧道掘进机运行及寿命周期的意义。

摘要：To study the relationship between grouting effect and grouting factors,three factors(seven parameters) directionless pressure and small cycle grouting model experiment on sandy gravel was done,which was designed according to uniform design *** regressing was applied to analysis of the test *** two models test results indicate that when the diffusing radius of grout changes from 26 to 51 cm,the grouted sandy gravel compressing strength changes from 2.13 to 12.30 MPa;the relationship between diffusing radius(R) and water cement ratio(m),permeability coefficient(k),grouting pressure(p),grouting time(t) is R=19.953m0.121k0.429p0.412t0.437;the relationship between compressing strength(P) and porosity(n),water cement ratio,grouting pressure,grouting time is P=*** the porosity of sandy gravel,the permeability coefficient of sandy gravel,grouting pressure,grouting time,water cement ratio are main factors to influence the grouting *** grouting pressure is the main factor to influence grouting diffusing radius,and the water cement ratio is the main factor to influence grouted sandy gravel compressing strength.

摘要：In recent years,a new type of foundation named composite piled raft foundation (also called long short composite piled raft) has been *** designing shallow foundations would mean unacceptable settlement,or other environmental risks exist which could impair the structure in the future,composite piled raft foundations could be *** element method was applied to study the behavior of this type of foundation subjected to vertical *** order to determine an optimal pile arrangement pattern which yields the minimum settlement,various pile arrangements under different vertical stress levels were *** show that with increasing the vertical stress on the raft,the effectiveness of the arrangements of short and long piles become more *** addition,a new factor named "composite piled raft efficiency" (CPRE) has been defined which determines the efficiency of long short piles arrangement in a composite piled raft *** factor will increase when short piles take more axial stresses and long piles take less axial *** addition,it is found that the changes in settlements for different long short piles arrangement are in a well agreement with changes in values of CPRE ***,CPRE ratio can be used as a factor to determine the efficiency of piles arrangements in composite piled raft foundation from the view point of reducing raft settlements.

摘要：This paper discusses the methods of establishing risk criteria for dams and reviews the application of dam risk criteria for individuals and societies in different countries or *** the conditions in China and considering the public safety and acceptance of dam risk,historical dam break data and current design standards,individual and societal risk criteria for dams are *** tolerable dam risk criteria for individuals should be set to 10-5–10-7 per annum based on project scale,for example,approximately 1.0×10-7 per annum,which corresponds to a reliability index of 4.2 based on a 100-year lifespan for a first-class or large *** societal limit for risk tolerance for dams should be set to approximately 10-3–10-5 per annum,corresponding to the fatality range from 1 to 100 and be horizontally extended to 1000,and F-N curves are *** was also found that the reliability indices of Chinese Standard(GB 50199-2013)and Eurocode1(2002)are different,but they have the same level of safety measured by the annual probability of *** research results have significance for establishing dam risk criteria.

摘要：超长隧道行车时间长,视觉环境单调,影响行车安全,增加了风险。通过在隧道内设置视觉疲劳缓解带,可以有效缓解行车疲劳。然而,视觉疲劳缓解带的设置形式,如其长度和位置,难以设计和量化。本研究提出了一种将虚拟现实设备与可穿戴式EEG设备集成的混合方法,以辅助设计人员设计超长隧道中的视觉疲劳缓解带。本研究的虚拟环境是基于云南某11.5 km超长隧道。结果表明,在隧道内使用自然景观装饰可以改善驾驶疲劳,驾驶人的注意力增长率提高20%以上。然而驾驶疲劳的累积对疲劳缓解效果有负面影响,因此疲劳缓解带的最佳位置是在驾驶疲劳刚出现的位置,而不是在积累了一定数量的驾驶疲劳的位置。

摘要：With rampant growth and improvements in drilling technology,drilling of blast holes should no longer be viewed as an arduous sub-process in any mining or excavation ***,it must be viewed as an important opportunity to quickly and accurately measure the geo-mechanical features of the rock mass on-site,much in advance of the downstream *** is well established that even the slightest variation in lithology,ground conditions,blast designs vis-à-vis geologic features and explosives performance,results in drastic changes in fragmentation *** in mind the importance of state-of-the-art measurement-while-drilling(MWD) technique,the current paper focuses on integrating this technique with the blasting operation in order to enhance the blasting designs and *** paper presents a preliminary understanding of various blasting models,blastability and other related concepts,to review the state-of-the-art advancements and researches done in this *** light of this,the paper highlights the future needs and implications on drill monitoring systems for improved information to enhance the blasting results.

摘要：受最新材料科学、计算机技术、人工智能和自动控制技术的启发,新一代交通基础设施正在走向数字化和智能化。世界上许多主要发达国家都在因地制宜,积极推动智能创新技术在交通基础设施中的应用。本文首先简要介绍了交通基础设施智能化的基本概念、科学依据和发展历程。然后,按照设计、施工、运维、淘汰的全生命周期链条,系统分析了智能化技术的研究现状和面临的主要挑战。随后,以世界上第一条基于智能建设理念建设的铁路——北京-张家口高铁为例,全面介绍了智能技术的最新成就。最后,从标准体系、理论方法和人才培养三个维度对交通基础设施智能化的未来发展进行了探讨。

摘要：级配方程可以准确和定量地表示粗粒料的级配,级配方程使得定量研究粗粒料级配与其物理力学性质之间的关系成为可能。提出了一个适用于描述粗粒料连续级配的级配方程,并对该级配方程的基本性质和适用性进行了研究。结果表明:提出的级配方程对粗粒料的级配具有良好的适用性。方程参数β的范围为(0,1),参数的大小决定了级配曲线的类型。当β大于0.5时,方程表示的级配曲线为反S形,否则为双曲线形。当β为0.13~1时,方程表示的级配为良好级配。对国内外土石坝用粗粒料的级配曲线进行了探讨,其参数值为0.18~0.97。该范围的确定对土石坝用粗粒料级配的设计具有指导价值。