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91.
西安地裂缝作为一种特殊的城市地质灾害,已经对基础设施造成很大的危害。长安路立交的破坏最为严重和典型,文章结合西安地裂缝的分布及活动特点,详细分析了地裂缝活动引起的长安路立交的破坏形式和特点。并对引起长安路立交破坏的原因做了进一步分析,得出了由于长安立交没有很好的排水措施导致地裂缝的异常活动从而引起桥梁破坏的结论。同时,文章还结合长安路立交的结构措施给出了在地裂缝带修建立交的结构措施建议。并最终得出了在地裂缝带修建城市立交等基础设施,应从采取措施减少地裂缝活动和采取合理的结构措施以适应地裂缝活动两方面进行综合考虑的结论。  相似文献   
92.
The northern Adriatic coast, which forms part of the Dinaric karst system, is bordered by high mountains. Here, the occurrence of rock-slides and rock-falls in road sections with high cuttings excavated in recent times and more than one century ago has been documented. Some of these old slopes were stable for a long time before rock-slides started to occur. We propose that these mass movements are favoured by karstification processes acting along joints in the exposed rock mass. The stress changes induced by overburden removal (excavation) cause dilation in the mass joint systems reducing the rock mass strength and facilitating the circulation of aggressive water. Changes in water pressure and temperature, wetting and drying cycles, and corrosion processes along discontinuity planes entail a reduction through time of the shear strength of potential failure surfaces.  相似文献   
93.
二朗山公路隧道岩爆特征与预测研究   总被引:6,自引:1,他引:5  
根据二郎山公路隧道施工中记录的200多次岩爆资料,总结隧道的岩爆特征,并采用“地质超前预报法”和“σθ/Rb判断现场测定预测法”两种方法,对岩爆预测问题进行有益探讨。  相似文献   
94.
公路桥梁地震易损性和震后恢复过程   总被引:5,自引:0,他引:5  
采用专家调查的方式,统计的我国各种主要公路桥梁在不同烈度的地震发生后可能遭受的结构破坏和功能损失,以及地震发生后所需要的恢复时间。通过分析,给出了大、中、小种规模的斜拉、悬索、板梁式和拱式桥梁的结构破坏概率矩阵、设施损失率、功能损失率分布、损失功能恢复所需要的时间和桥梁在遭受破坏期间所损失的工作日数,并将研究结果与唐山地震之后的实际调查结果进行了对比,得到了一些有益的结果。  相似文献   
95.
道路交通事故现场快速测绘系统   总被引:1,自引:0,他引:1  
介绍道路交通事故现场快速测绘系统的设计原理、系统构成、系统功能和主要技术。  相似文献   
96.
The potential of marble dust as a stabilizing additive to red tropical soils was evaluated. The evaluation involved the determination of the geotechnical properties of three different red tropical soils in their natural state as well as when mixed with varying proportions of marble dust. The parameters tested included the particle size distribution, specific gravity, Atterberg limits, the standard compaction characteristics, the compressive strength and the California bearing ratio (CBR). The strength tests were repeated after normal 28 day curing of the treated samples and also after accelerated 24 h curing at temperatures of 40°C, 60°C and 80°C.

Results showed that the geotechnical parameters of red tropical soils are improved substantially by the addition of marble dust; plasticity was reduced by 20 to 33% and strength and CBR increased by 30 to 46% and 27 to 55% respectively. The highest strength and CBR values were achieved at 8% marble dust. Results also showed that normal 28 day curing improved the strength of the marble dust-treated soil with over 80% strength gain achieved after 7 to 10 days of normal curing. Higher strength development was realised following accelerated 24 h curing at 60°C.

Although these results imply marked improvement in the geotechnical parameters of red tropical soils, the higher strength developed is not enough for the improved soil to be used as a base material in the construction of heavily trafficked flexible pavements. The improved material may, however, be successfully used as base material for lightly trafficked roads and as a sub-base material for heavily trafficked roads.  相似文献   

97.
基于线路设计模型的一体化中线测设方法研究   总被引:2,自引:0,他引:2  
刘国祥  张献州 《四川测绘》1999,22(3):132-135
本文针对线路(包括铁路和公路)的中线测设计算量大、野外作业条件的不可预知性和劳动强度大等特点,介绍了一种基于线路设计模型的一体化中线测设的教学模型及方法,以此为基础开发了实用的中线放样程序并运用于我国第一条磁悬浮线───交大青城磁浮列车试验示范城的中经测设中,实践证明一体化的思想及方法具有高效、灵活和可靠性等特点。  相似文献   
98.
2017年8月8日九寨沟7.0级地震引发贯通重灾区的S301省道、Z120县道多处损坏,给应急救援和灾后重建带来较大困难。利用高分辨率无人机和卫星影像可以对道路震害情况进行评估。本文首先对道路震害进行破坏类型和破坏等级的划分,针对不同分辨率影像所表现的道路破坏特征,建立各破坏等级、各损坏类型的解译标志,并完成灾区遥感图像覆盖范围内主要道路震害的研判与评估。经统计分析,研究区域共出现110处明显破坏,其中,68处为部分损坏,42处为完全损毁,道路整体破坏严重。  相似文献   
99.
Approximately 80% of the road network in Brazil is unpaved and shows evidences of a high erosion potential. In the semi-arid Caatinga Biome in the northeast of the country, a monitoring programme has been done for two years in order to analyze runoff and sediment production from unpaved rural road-ways and from embankments. Sediment production ranged from 0.30 to 0.92 Mg/ha yr, higher than in undisturbed areas, but generally lower than that reported for unpaved roads in other regions. However, this is a semi-arid area with low rainfall and runoff and, hence, with a limited hydrological connectivity and sediment production. Sediment production on an embankment with no vegetation was around ten times higher than on an embankment with vegetation. On the road surface, annual sediment production (normalized for gradient) in a section with traffic was three times higher than for a road surface without traffic. In addition, events that occurred after roadway maintenance activities generated peaks of sedi-ment concentration of over 5000 mg/L. These results suggest that sediment production from roads and embankments with bare surfaces is at least one order of magnitude higher than in undisturbed catch-ment areas. Maintenance activity and vehicle traffic contribute to an increase in sediment availability and impact on the sediment concentration, but less intensely on sediment loads, which depend on the runoff magnitude of the events occurring after roadway maintenance. It was also found that the natural vegetation of the semi-arid region potentially captures sediment on roadway embankments;thereby playing an important role in breaking connectivity between the sediment flow from unpaved roads and the natural drainage system of the catchment.  相似文献   
100.
依托“冰上丝绸之路”大背景,综合分析陆河联运路线的最新研究成果,提出纵向联通中国东北和俄罗斯西伯利亚地区两条经济带的路线,即大连到北冰洋季克西港陆河联运路线(简称陆河联运路线)。陆河联运沿线的主要城市包括:大连—哈尔滨—黑河—布拉戈维申斯克(海兰泡)—涅留恩格里—雅库茨克—季克西港。陆河联运路线的陆运段主要是中国大连市到俄罗斯雅库茨克市的铁路,河运段是俄罗斯雅库茨克市到季克西港的勒拿河下游水运航道。陆河联运路线的陆运段各城市节点拥有相对成熟的交通体系、设备完善的交通站点和较好的经济发展前景;河运段每年至少可以通航3个月(7-9月),且在勒拿河中下游河段可通航3000 t以上的船舶。中俄东北亚陆河联运路线在7-9月具备运输距离和时间短等特点。  相似文献   
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