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本文介绍主要采用有限元数值方法,以高架桥建设为工程背景,对该工程桩基面临的邻近隧道施工问题进行了数值分析研究.主要从地表变形、桩基变形、桩侧阻等角度对桩基的性状进行深入分析,以期明确隧道施工对桩基造成的影响. 相似文献
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随着我国交通事业的发展,隧道工程事业在铁路事业中的应用也越来越广泛.由于隧道工程施工的复杂性和特殊性,隧道工程中的贯通误差分析便成为隧道工程方案设计的关键部分.隧道工程贯通误差包括横向贯通误差、竖向贯通误差,其中,横向贯通误差在隧道施工过程中影响较大,是隧道施工中最重要的因素和最关键的技术指标.本文首先概述隧道工程的贯通误差,进而分析隧道工程横向贯通误差的影响因素以及误差分析的具体要求.寄希望对我国隧道工程横向贯通误差的控制有一定的帮助. 相似文献
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隧道渗漏水痛害不仅时隧道结构产生影响,同时在公路中对电力配线有较大影响.本文结合工程实际,阐述改性WPV化学水泥浆液在处理隧道渗漏水病害中的应用,提出了针对隧道渗漏水痛害的处理方法. 相似文献
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青藏铁路工程迹地对植被的影响评价 总被引：2，自引：0，他引：2
应用植被影响指数分析评价青藏铁路工程迹地对沿线典型植被的影响。结果表明,受工程迹地影响最大的植被类型主要是高寒草原和高寒草甸植被,其次是高寒荒漠和高寒流石坡稀疏植被,影响较小的是高寒河谷灌丛、高寒沼泽湿地和高寒垫状植被;对青藏铁路沿线植被产生毁灭性影响的工程迹地类型为路基工程;产生严重影响的工程迹地类型为取弃土场、桥涵和隧道工程;施工便道、站场和施工营地对各种类型的高原植被产生了一般或轻微的影响;研究结果对于青藏铁路沿线工程迹地的植被恢复具有指导意义。 相似文献
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隧道在高原山岭等地区道路建设中被广泛采用，但其对土壤有机碳稳定性的影响研究较少。土壤有机碳稳定性是评价土壤生态系统对外界环境变化响应的重要指标。为阐明土壤有机碳(SOC)对隧道工程建设的抗干扰能力，本研究以雅鲁藏布江下游隧道建设为依托，设置工程影响区(ED)和非影响区(CK)监测样地，从土壤活性有机碳(LOC)、团聚体和土壤酶活性等角度探究隧道建设对SOC稳定性的影响。结果表明，工程影响区SOC、LOC含量分别为291.40和110.28 mg·kg-1,CK区域中分别为255.31和91.19 mg·kg-1，两个区域差异不显著(P> 0.05)。ED和CK中，土壤粒径> 0.25 mm的团聚体占比均超过80%，随着团聚体粒径减小，ED的SOC含量呈现降低趋势，但ED与CK差异不显著。本研究表明，隧道建设未改变植被凋落物量，对SOC的输入与输出未产生显著影响。ED与CK区土壤酶、微生物生物量碳及土壤团聚体组成无显著差异，表明隧道工程建设对SOC稳定性的微生物学调控机制及土壤团聚体物理保护机制无显著影响，对SOC稳定性无显著影响。... 相似文献
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在掘进隧道的施工过程中,施工设备的性能决定工程进度和施工安全,所以本文分析了掘进隧道时施工设备的安全性,结合工程实践,对隧道施工设备的管理安全进行了研究,并提出了一些对施工设备进行信息化管理的方案。 相似文献
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隧道的建设是解决人流与车辆的主要交通要道,其施工质量优劣将影响到城市的建筑发展与人员的生命安全。本文从介绍隧道工程的主要特征入手,主要介绍了隧道工程的施工技术和如何科学进行施工组织管理。 相似文献
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Evidence for the non-involvement of the uterus in the lifespan of the corpus luteum in the cyclic dog 总被引：1，自引：0，他引：1
Progesterone levels in peripheral blood of dogs were analysed during the cycle in which hysterectomy (n = 5) or sham surgery (n = 3) was performed as well as during the cycle of dogs (n = 5) hysterectomized at least one year prior to this study; the data were compared with the findings in control dogs (n = 3). The averages of the duration of the luteal period observed in the three experimental groups were not significantly different from those of control dogs. Immediately after surgery, the progesterone level decreased from 25 to 50% of the presurgical level, but returned to presurgical level in about four days. Prolactin levels were elevated for about 30 h after surgery. Nevertheless, the averages of the mean prolactin levels for each animal during the luteal period of the experimental groups were not significantly different from those of control dogs. It is concluded that in the dog, the uterus is not involved in the lifespan of the cyclic corpus luteum. 相似文献
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嗅源是军犬嗅觉作业训练的依据.军犬鉴别中嗅源能力的培养在整个鉴别训练中占有重要地位,关系到鉴别训练的成败和鉴别能力的提高.所以,军犬在嗅认嗅源时必须按照训犬员的指令充分、细致地感受嗅源气味,并且对嗅源气味产生兴奋反应.如何培养军犬充分嗅认嗅源以及及时解决嗅认过程中出现的问题,成为我们进行鉴别训练的关键.…… 相似文献
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Meschan EM Peham C Schobesberger H Licka TF 《Veterinary journal (London, England : 1997)》2007,173(3):578-584
As there is no statistical evidence that saddle fit influences the load exerted on a horse's back, this study was performed to assess the hypothesis that the width of the tree significantly alters the pressure distribution on the back beneath the saddle. Nineteen sound horses were ridden at walk and trot on a treadmill with three saddles differing only in tree width. Kinetic data were recorded by a sensor mat. A minimum of 14 motion cycles were used in each trial. The saddles were classified into four groups depending on fit. For each horse, the saddle with the lowest overall force (LOF) was determined. Saddles were classified as "too-narrow" if they were one size (2 cm) narrower than the LOF saddle, and "too-wide" if they were one size (2 cm) wider than the LOF saddle. Saddles two sizes wider than LOF saddles were classified as "very-wide". In the group of narrow saddles, the pressure in the caudal third (walk 0.63 N/cm(2)+/-0.10; trot 1.08 N/cm(2)+/-0.26) was significantly higher compared to the LOF saddles (walk 0.50 N/cm(2)+/-0.09; trot 0.86 N/cm(2)+/-0.28). In the middle transversal third, the pressure of the wide saddles (walk 0.73 N/cm(2)+/-0.06; trot 1.52 N/cm(2)+/-0.19) and very-wide saddles (walk 0.77 N/cm(2)+/-0.06; trot 1.57 N/cm(2)+/-0.19) was significantly higher compared to LOF saddles (walk 0.65 N/cm(2)+/-0.10/ 0.63 N/cm(2)+/-0.11; trot 1.33 N/cm(2)+/-0.22/1.27 N/cm(2)+/-0.20). This study demonstrates that the load under poorly fitting saddles is distributed over a smaller area than under properly fitting saddles, leading to potentially harmful pressures peaks. 相似文献
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Observations on the Pathology of the Spleen of the Cat 总被引：1，自引：0，他引：1
Abstract— Lesions were found in the spleen of four of sixty-three cats examined post mortem in the department, and comprised two examples of lymphosarcoma, one of chronic fibrinous peritonitis and one of subcapsular haematoma. Abnormalities were found in two cat spleens received from veterinary surgeons in general practice. In one cat the abnormalities were an haemangiosarcoma with secondary deposits in the liver and in the other extensive mast cell infiltration. In addition lesions were detected in the spleen of three of eighty-seven cats examined post mortem in general practice. The lesions were: multiple secondary deposits of adenocarcinoma from a primary tumour of the mammary gland, a ruptured spleen and a foreign body below the splenic capsule. Résumé— L'examen microscopique de soixante-trois chats pratiqué dans le service a permis de rencontrer quatre fois des lésions de la rate, dont deux lymphosarcomes, une péritonite capsulaire fibrineuse et un hématome sous-capsulaire. D'autre part des lésions ont été trouvées dans deux rates de chat expédiées par des vétérinaires exerçant en pratiaue générale. Chez un chat il s'agissait d'un htmangiosarcome avec métastases hépatiques et chex l'autre d'une infilt ation diffuse par des mastocyta. De plus, on a rencontré des llésions dnas la rate de trois chats parmi quatre-vingt sept autopsies effectuées dans le cadre d'une clientèle génárale. Ces iésions étaient dés métastases multiples d'un adénocarcinome dont la tumeur primitive siègeait dam la glande mammaire, une rupture de la rate et un corps érangers sou capsulaire. Zusammenfassung— Läsionen der Milz wurden bei vier von dreiuiidsechzig in dieser hbteilung sezierten Katzen gefunden, und zwar in zwei Fällen ein Lymphosarkom, in einem Falle eine chron-ische fibrinöse Peritonitis und in einem ein subkapsuläres Hématom. Anomalien fanden sich auch in der Milz von zwei Katzen, die aus der tierxrztlichen Praxis eingesandt wurden. Bei der einen Katze war dies ein Hämangiosarkom mit Metastasen in der Leber, bei der anderen eine weitläufige Infiltration der Mastzellen. Außerdem wurden bei drei von siebenundachtzig in der Praxis sezierten Katzen Milzläsionen gefunden. Diese bestanden am multiplen Metastasen eines Adenokarzinoms der Brustdrüse, einer Milzzerreissung und einem Fremdkörper unterhalb der Milzkapsel. 相似文献