2006前11个月中国工程机械市场分析

The Excavator Market Statistics from China Construction Machin-ery Association(CCMA)show that the 19 primary enterprises(including 10 joint ventures or foreign-funded enterprises)in China's excavator industry sold about 42874 excavators in the first eleven months of 2006,a 62.8 percent increase from the same period of 2005 when 14 primary enterprises(including 10 joint ventures or for eign-funded enterprises)     

Classification and assessment of rock mass parameters in Choghart iron mine using P-wave velocity

Engineering rock mass classification,based on empirical relations between rock mass parameters and engineering applications,is commonly used in rock engineering and forms the basis for designing rock structures.The basic data required may be obtained from visual observation and laboratory or field tests.However,owing to the discontinuous and variable nature of rock masses,it is difficult for rock engineers to directly obtain the specific design parameters needed.As an alternative,the use of geophysical methods in geomechanics such as seismography may largely address this problem.In this study,25 seismic profiles with the total length of 543 m have been scanned to determine the geomechanical properties of the rock mass in blocks Ⅰ,Ⅲ and Ⅳ-2 of the Choghart iron mine.Moreover,rock joint measurements and sampling for laboratory tests were conducted.The results show that the rock mass rating(RMR) and Q values have a close relation with P-wave velocity parameters,including P-wave velocity in field(V_(PF)).P-wave velocity in the laboratory(V_(PL)) and the ratio of V_(PF) V_(PL)(i.e.K_p = V_(PF)/V_(PL).However,Q value,totally,has greater correlation coefficient and less error than the RMR,In addition,rock mass parameters including rock quality designation(RQD),uniaxial compressive strength(UCS),joint roughness coefficient(JRC) and Schmidt number(RN) show close relationship with P-wave velocity.An equation based on these parameters was obtained to estimate the P-wave velocity in the rock mass with a correlation coefficient of 91%.The velocities in two orthogonal directions and the results of joint study show that the wave velocity anisotropy in rock mass may be used as an efficient tool to assess the strong and weak directions in rock mass.     

Effect of the Chord-Brace Angle on the Strength of Rectangular Hollow Sections K- and N-Joints in Galvanized Structures

An important consideration when using hot-dip galvanized tubular structures is the uncertainty of the joint behaviour due to the possible reduction in the global joint resistance produced by the vent holes required for the galvanizing process. This paper assesses the effect on the joint strength of the angle between the brace members and the chord in a K- or N-joints made with rectangular hollow sections. The study is focused on the case when those brace members include characteristic holes required for the hot-dip galvanizing process. To accomplish the objective of the proposed work, some tests on full-scale K- and N-joints, including angles of 35°, 45°, 55° and 90°, were carried out. The experimental work was complemented by a validated numerical simulation in order to give some design recommendations and to extend the research to other joint configurations.     

辽西中生代火山喷发旋回划分与地质意义

With the rapid development of the tourism market in mainland China and the quick expansion of tourism in the rural and village region (alternatively called rural area or RA or village area of China or VAC for short), more and more attention has been jetted into this field at the same time, and it also attracts the attention from the government and raises the interests of experts and scholars. In this paper, the recent definition of tourism in the rural and village region(alternatively called rural area or RA or village area of China or VAC for short) is given out, and tourism in the rural and village region(alternatively called rural area or RA or village area of China or VAC for short) development is also the main concern, the analysis of the development of tourism in the rural and village region(alternatively called rural area or RA or village area of China or VAC for short), tourism in the rural and village region (alternatively named as rural area in China or called RAC for short) development programs and measures for analysis.     

Call for Papers

正As the only professional and academic English periodical in the area of urban planning and design in China, China City Planning Review (CCPR) is jointly supported by the Urban Planning Society of China, the Center for Human Settlements of Tsinghua University, the School of Architecture of Tsinghua University, and the Beijing Tsinghua Tongheng Urban PlanningDesign Institute Co.Ltd.ArticlesinCCPRmainlycovervariousstudiesonChinesecitiesfromtheperspectiveofurbanplanninganddesign,including status quos, problems, trends, planning strategies and relative policies of their development. It offers the readers with different opinions and criticism from both home and abroad, giving a full understanding of what has happened or is happening in Chinese cities.     

A new interpretation for formation of orthogonal joints in quartz sandstone

Two vertical and orthogonal systematic joint sets are generally arrayed in a grid pattern on the bedding surface,which are the significant features of flat-lying sandstone terrains.Although extensive researches are reported on this topic,many fundamental problems have still not been solved.Such mutually perpendicular opening-mode fractures are an obvious manifestation of effective tensile stresses in two orthogonal directions in the horizontal bedding plane.A good understanding of these orthogonal joint systems is a key to structural analysis,landscape interpretation,and guidance of resolving a number of very practical problems in engineering,mining and hydrologic projects.Based on an anatomic investigation on the orthogonal joints in the Potsdam sandstone of Cambrian age at Ausable Chasm(New York State,USA)and Beauharnois(Quebec,Canada),we proposed that the orthogonal joints may result from the auxetic effects of quartz-rich sandstone rather than local or regional rotation of the maximum tensile stress(σ₃)direction by about 90°.The sandstone beds with negative Poisson's ratios are so fascinating that,when placed under vertical burial compression and layer-parallel extension in one direction(σ₃),it becomes stretched in the transverse direction(σ₂),producing two orthogonal sets of mutual abutting and intersecting joints(J1 and J2 normal toσ₃ andσ₂,respectively),and both are normal to the bedding surface.Joint set J1 is more closely-spaced than J2 by a factor of～3.3,which is correlated with an average Poisson's ratio of?0.3 for the Potsdam sandstone at the time of joint formation.     

Glossary

正Big-Pot Meal(大锅饭dà guō fàn):It is a metaphor for the phenomenon of absolute equalitarianism in distribution,which is mainly used to describe two situations in China particularly under the circumstance of planned economy.①For state-owned enterprises,no matter how their business goes,the due financial allocation from the government would never change;②For the employees of any     

Experimental study of water curtain performance for gas storage in an underground cavern

An artificial water curtain system is composed of a network of underground galleries and horizontal boreholes drilled from these galleries.Pre-grouting measures are introduced to keep the bedrock saturated all the time.This system is deployed over an artificial or natural underground cavern used for the storage of gas（or some other fluids） to prevent the gas from escaping through leakage paths in the rock mass.An experimental physical modeling system has been constructed to evaluate the performance of artificial water curtain systems under various conditions.These conditions include different spacings of caverns and cavern radii located below the natural groundwater level.The principles of the experiment,devices,design of the physical model,calculation of gas leakage,and evaluation of the critical gas pressure are presented in this paper.Experimental result shows that gas leakage is strongly affected by the spacing of water curtain boreholes,the critical gas pressure,and the number and proximity of storage caverns.The hydraulic connection between boreholes is observed to vary with depth or location,which suggests that the distribution of water-conducting joint sets along the boreholes is also variable.When designing the drainage system for a cavern,drainage holes should be orientated to maximize the frequency at which they encounter major joint sets and permeable intervals studying in order to maintain the seal on the cavern through water pressure.Our experimental results provide a significant contribution to the theoretical controls on water curtains,and they can be used to guide the design and construction of practical storage caverns.     

Experimental Vibration Analysis of a Cracked Laminated Glass Beam with Bolted Joint

In this study, in order to determine the very early load transfer behavior in the bolted joint connection, experimental dynamic analysis of different laminated glass beams including two surface cracks is considered. For this purpose, both three different plastic interlayers （i.e., three types of polyvinyl butyral--PVB） and three different glass-lamina thicknesses are taken into account. Effects of the plastic interlayer, thickness of the glass-lamina, number of surface cracks and their locations on the vibration characteristics/structural performances are examined experimentally. Vibration tests are performed to present free vibration characteristics of the laminated glass beams under clamped-free boundary conditions. Experimental dynamic analysis consists of six parts： （I） vibration analysis with no-crack and no-hole with a bolted joint; （I1） vibration analysis with a surface crack and no-hole with a bolted joint; （III） vibration analysis with two surface cracks and no-hole with a bolted joint; （IV） vibration analysis with no-crack and a hole with a bolted joint; （V） vibration analysis with a surface crack and a hole with a bolted joint; （VI） vibration analysis with two surface cracks and a hole with a bolted joint. For these experimental steps, an impact hammer with a force transducer is used to excite the uncracked or cracked composite beams through the selected points. After the excitation, the responses are obtained by an accelerometer. The vibration measurements are completed using a microprocessor-based data acquisition system and nCode GlyphWorks software. Results are given in tabular and graphical forms.     

Message from the Chief Editor

正On the 30~(th) Anniversary of China City Planning Review The journal of China City Planning Review was founded by the Urban Planning Society of China in 1985 and saw its first issue published worldwide in the same year.Managed by Prof.Chen Zhanxiang,the Chief Editor then,and with thanks to the great support and assistance from both the Chinese(including Hong Kong)and international experts and     

我国工程机械产品出口状况及面临的挑战

1工程机械行业出口概况1.1工程机械行业"十一五"期间运行主要指标(见表1)1.22010年行业运行主要经济指标据协会统计:全国工程机械行业主要企业主要产品销售收入同比增长52.27%;主要产品销量同比增长61.63%(见表2)。1.32011年12月主要经济指标据协会统计:2011年1~2月全国工程机械行业主要企业主     

2012年1季度工程机械进出口分析

"东方不亮西方亮",对于2012年一季度中国工程机械行业国内外市场而言,正应了这句话。在国内工程机械市场主要机种销量呈现普遍大幅下滑之时,出口市场却交出了一份令人惊喜的答卷。本文从中挑选出具有代表性的几个机种进行了进出口分析,为读者全面把脉国外市场提供了参考。     

危机下的对策

2008年,注定是个令人难忘的年份.2008年的工程机械行业有点"过山车"的感觉,先是一路上升,并创造了历史高峰;2008年上半年,中国工程机械行业的销售收入同比增长50.5%,其中工程起重机行业同比增长达93.3%,铲运机械同比增长39.2%.     

2010年最具影响力产品

2010年,对于中国工程机械行业而言,是绝对给力的一年。这一年,虽然全球金融危机的阴霾尚未完全散去,但中国工程机械市场却形势大好。据初步统计,2010年中国工程机械市场销售额突破4000亿元已成定局,同比增幅超过30%,实现了工程机械行业十一五的完美收官。所有机种几乎都呈现积极正增长态势,主要机种销量一路走高,创下历史最好成绩,在中国工程机械发展史上写下了浓墨重彩的一笔。《建筑机械》特别审慎选取了十余个关键词,希望通过它们,能将2010年影响行业的大事件进行浓缩再现。     

2011年上半年中国工程机械主要机种销售情况

2011年上半年中国工程机械主要机种销售情况已经公布,1季度工程机械各主要机种销售业绩捷报频传,但是进入4月份,行业整体增幅明显放缓,包括挖掘机、装载机、推土机等主要机种都出现了环比30%左右的下滑,6月份挖掘机、推土机较2010年同期下降10%以上。本文对工程机械部分机种2011年上半年市场销售及出口情况作以简析,以供读者参考。     

2012年1季度中国工程机械主要机种销售情况

进入2012年,工程机械行业没有上演2011年年初的增长态势,行业整体增幅明显放缓。随着1季度各主要机种销售数据的陆续公布,土方机械、起重机械、路面机械、桩工机械等主要机种销量较2011年同期下降15%以上,产品销售收入除个别机种外均下降20%以上。本期对工程机械部分机种2012年1季度市场销售及出口情况进行盘点,将进入2012年短短几个月以来,工程机械各主要机种呈现的变化和趋势呈现给读者,为其了解市场提供参考.     

国产配套件 而今迈步从头越

2010年中国工程机械全行业销售额突破4200亿人民币,已超越北美、日本、欧洲,一跃成为全球最大的工程机械市场。在中国工程机械行业辉煌之时却需要严肃的面对一个不争的事实——中国大部分包括液压机和传动系统的关键配件需要从国外进口。国家和行业也通过种种方式来鼓励配套件行业的发展和进步,一切的一切都标志着,国产配套件的崛起将毋庸置疑,市场的格局即将改写。     

代理商论道市场变奏

当前,中国工程机械市场一直在低谷徘徊,代理商都面临着巨大的压力。尤其是以新机销售为主要盈利模式的企业,都切实地感受到了市场急剧变奏带来的严峻考验。告别销量为王的时代,代理商应该如何把握新形势下的市场脉搏?代理商的盈利模式究竟是什么?向工程机械后市场转型能否解决代理商持续发展的难题?代理商群体未来的机遇与挑战又在哪里……     

关爱中小代理商发展——记2012中小代理商昆山研讨会

2011年下半年至今,中国工程机械市场销量下滑,行业进入不景气通道,部分代理商库存较高,回款困难,逾期率普遍高于往年,行业企业都面临着严峻考验。针对这一情况,2012年中国工程机械工业协会代理商工作委员会开展以"关     

2012高端论道

说起2011年中国工程机械市场的发展,业界多用"不平凡"三字来形容。确实,这一年市场以一种少见的"前高后低尾稳"之势玩了一把刺激的心跳游戏,虽然过程胆战心惊,但结局却有惊无险。据初步统计,2011年全国20大类工程机械产品的销售收入突破5000亿元,同比增长17%以上,全行业产销数额已双双排名世界第一。回顾近5年我国工程机械行业的发展,从