高压旋喷桩有关问题的探索和研究

通过工程实例，介绍了单管法高压旋喷桩施工工艺、技术参数、施工中存在的问题以及注意事项。阐述了一些常见故障及预防措施。     

Racism and Intolerance in Eastern Australia: a geographic perspective

Racism has become a fact of life in Australia over the past decade or so, yet there are relatively few studies of its nature or extent, and still fewer on its geography. Using a social constructivist approach, this study draws on a survey of 5056 respondents to investigate attitudes to racism and cultural diversity in New South Wales and Queensland, and of perceptions of out-groups as instances of ‘strangers in our midst’. On racism, results show the presence of a continuum of attitudes ranging from generally tolerant to generally intolerant, a presence which cuts across compositional (social or aspatial) characteristics to emphasise the existence of a distinctive geography, an everywhere different nature to racist and non-racist attitudes which transcends urban–rural and traditional social layers. On the other hand, perceptions of out-groups are not uniformly correlated with presence or absence of cultural diversity. In many cases, the ability to make judgements about significant ‘others’ or out-groups has been shown to relate more to abstract notions of self and national identity, reproduced in public by mainstream news media and political leaders. In particular, it may reflect an Anglo (or Anglo-Celtic) view on nationalism, which is a hallmark of the ‘new racism’: an assimilationist or ethnocultural view of Australian society which is different from the ‘civic nation’ ideal envisaged by multiculturalism. That the geography of attitudes and perceptions people have towards and about different cultural groups is so ‘everywhere different’ has important implications for attempts to address and redress issues of intolerance in Australia.     

Construction Problems on the Karstified Limestone Tuffs of Condeixa, Central Portugal: A Case Study

During the excavations for the foundations of a three storey building on the limestone tuffs of Condeixa, Central Portugal, a large dissolution fissure and smaller dissolution voids were found. Since the area has never been the subject of engineering geology investigation, it was decided to evaluate the risk associated with the construction of the building. These limestone tuffs were formed in a continental environment by the precipitation of calcite carried by the water coming from the large limestone body in the east. The precipitated calcite mixed with the terrigenous materials and around trunks and leaves of plants, originating a very heterogeneous and porous ground, which is characteristic of limestone tuffs. The study started with a detailed geological survey followed by a large number of destructive drillings, located essentially under the pad foundations. The results revealed several karstic cavities with serious problems for the building foundations and the structure, and many smaller dissolution cavities, often filled with clayey soils. The ground treatment solutions used included, dental cleaning, filling with concrete or granular material the dissolution structures accessible at the level of the foundation, reinforcement of the footing and the structure of the building and adding a continuous foundation beam to hold the foundations together. The cost of the engineering geology study, site investigation, ground treatment, and the reinforcement of the foundation and building, increased the total construction cost from 2%, at the design stage, to 4.8%.     

青藏高原清水河多年冻土区铁路路基沉降变形特征研究

通过埋设在青藏铁路路基中两个断面内的6条沉降观测管3 a来的地基沉降变形资料,研究了高原多年冻土区铁路路基的沉降变形特征,分析了填筑铁路路基对下伏多年冻土融化变形的影响。研究表明,由于受到填筑路基时赋存在路基填料内的热量的影响,铁路路基下伏多年冻土上限在施工初期会有一个明显的下移沉降,铁路路基也随之有一个较大幅度的工后下沉变动,随着时间的推移,路基下降速率会逐渐下降,但在短时间内不会停止下来,而且由于太阳辐射和路基边坡形状的影响,路基向阳面与背阴面的变形有较大的差别,且在近南北向展布的路基上表现最为明显。     

小型水电站建设用地地质灾害评估技术研究——以湄尼多河小型水电站为例

现阶段,地质灾害评估技术人员在评估实践中,往往不注重各评估对象的差异性,采取同一评估模式,结果达不到评估的目的。在对小型水电站进行评估时,野外调查的重点,评估过程中所使用的方法以及危险性现状、预测及综合分区评估等与大型水电站、路线工程、矿山开采、民用建筑等工程有所不同。湄尼多河小型水电站工程位于云南省怒江州福贡县马吉乡境内,地质环境条件复杂,评估级别综合为二级。文章以该电站建设用地地质灾害危险性评估为例,对小型水电站建设用地地质灾害危险性评估的方法与理论进行探讨。     

Construction techniques for the Taklamakan Desert Highway: research on the construction materials and the results of field tests

After conducting many laboratory and field experiments, several key technical issues related to the construction of China’s Taklamakan Desert Highway have been satisfactorily resolved. In particular, considerable progress has been made on the dry compaction of a sand sub-base, road design parameters, the creation of a structure that combines a sub-grade and asphalt pavement, analysis of the stability of a sand sub-base strengthened with geotextiles, and on the development of a complete set of construction techniques. The achievements of this research were successfully applied for the first time in the Taklamakan Desert, where the environmental conditions are extremely harsh. The results suggest that the construction of this highway was economical and that the simple construction methods produced a reliable highway. The resulting highway is believed to be the world’s first long-distance graded highway running through a huge desert with migrating dunes.     

基于全站仪的圆形建筑物倾斜观测的方法和精度

随着建筑物的不断增高、增大,其稳定性和可靠性成为人们关注的焦点.其中建筑物的倾斜度是衡量施工技术质量的重要指标之一.而传统的观测方法如经纬仪测小角法、经纬仪投点法,由于受仪器精度和观测条件的限制,观测精度较低.拓普康全站仪独具推出的圆柱偏心测量功能为快速、准确测定圆形建筑物的倾斜量开辟了一条新途径,本文阐述了基于全站仪的圆形建筑物倾斜观测的原理和方法,并对其精度进行分析.     

煤矿井简检查孔施工技术探讨

介绍了煤矿井筒检查孔的特点和技术、质量要求,总结了以往工程中的经验教训,针对工程中的技术难点,如取心、孔斜控制、抽水作业和冲洗液选择与维护等影响质量、工期的关键环节提出了技术措施,为优质、高效施工此类工程提供借鉴.     

高速公路桥头跳车病害的分析与治理方法探讨

根据高速公路桥头跳车病害探地雷达检测结果,结合路基实际工程地质资料及沉降观测值,分析出造成此病害的原因是桥与路之间沉降差异所致,故搭板与垫层和垫层与路基之间产生了脱空,造成桥搭板、垫层碎裂而出现了桥头跳车病害.针对病害根源,采用了压密注浆进行搭板加固及重新摊铺沥青混合料进行调坡处理的治理方法.     

加强工程施工项目管理措施与建议

结合项目施工管理的经验,从建立项目管理班子、项目评估和合同评审签订、人力资源的优化配置、强化劳务管理、责任成本管理、建立激励约束机制六个方面来探讨加强工程项目管理办法,并同时提出了加强工程项目管理的具体措施与建议.