水泥土深层搅拌桩在长江堤防管涌险段治理工程中的应用   总被引：1，自引：1，他引：0  

段新胜  顾湘  张鸣 《水文地质工程地质》2000,27(5):47-50

本文通过一工程实例介绍水泥土深层搅拌桩技术在治理长江堤防管涌险段工程中的设计原则和施工,检测方法及应该注意的问题。  相似文献   

Characteristics of thawed interlayer and its effect on settlement beneath embankment in permafrost regions—A case study for the Qinghai-Tibet Highway     

ZhiZhong Sun  HongLei Wang  WenJie Feng  YongZhi Liu  ShuJuan Zhang 《寒旱区科学》2017,9(5):447-454

Based on ground temperatures and deformations monitored at the Xieshuihe site along the Qinghai-Tibet Highway(QTH)in permafrost regions from 2004 to 2015,variation of artificial permafrost table(APT),maximum frozen depth(MFD),thawed interlayer thickness(TIT)and ground temperature beneath embankment is analyzed,respectively.The results indicate that under the embankment,the change of APT occurred from October to December of that year and presented a deepening trend.The change of MFD occurred from April to June of that year with no obvious change trend,and TIT had an increasing trend year by year,which mainly resulted from the deepening artificial permafrost table.Mean annual ground temperature at 0.5 m depth was 3.91°C higher beneath the embankment center than that under the natural field.The rising ground temperature at shallow layer of embankment resulted in the development of thawed interlayer beneath the embankment and warming of underlying permafrost.Embankment settlement is closely associated with TIT.Greater settlement easily occurs when permafrost with higher ice content exists under the thawed interlayer,and in turn the settlement is smaller when permafrost with lower ice content exists under the thawed interlayer.  相似文献   

Numerical analysis on the thermal regimes of thermosyphon embankment in snowy permafrost area     

Yan Lu  Xin Yi  WenBing Yu  WeiBo Liu 《寒旱区科学》2017,9(6):580-586

Snow covers the road embankments in winter in high latitude permafrost zones. The effect of snow cover on embankments was simulated based on field measurements of boundary conditions and initial ground temperature profile in Mohe, China. The effect of thermosyphons on the embankment warmed by snow cover was evaluated by numerical simulations as well. The results indicate that the difference of thermal regimes between non-thermosyphon and thermosyphon embankments reaches to 22 m in depth below the ground surface. It is much warmer in the non-thermosyphon embankment body in winter. Affected by the snow cover, heat flux gradually spreads into the deep ground of the subgrade over time. The permafrost table under the slope toe of a thermosyphon embankment is 1.2 m higher than that of a non-thermosyphon embankment in the 20th year. In addition, the permafrost table at the slope toe of a thermosyphon embankment is 26 cm deeper over 20 years. These results indicate that thermosyphons can greatly weaken the warm effect of snow cover. However, thermosyphons cannot avoid the degradation of permafrost under the scenarios of snow cover. Therefore, composite measures need to be adopted to keep embankment stability in snowy permafrost zones.  相似文献   

Performance of reinforced,DMM column-supported embankment considering reinforcement viscosity and subsoil’s decreasing hydraulic conductivity     

《Computers and Geotechnics》2016

It has been widely accepted that reinforcement made of polyethylene and polypropylene is susceptible to creep and soil’s hydraulic conductivity varies with its void ratio. However, unfortunately there is no available sensitivity analysis on time-dependent embankment behaviour taking either reinforcement viscosity or time varying hydraulic conductivity of subsoil into consideration. The influence of geosynthetic reinforcement viscosity and decreasing hydraulic conductivity with consolidation on the time-dependent performance of embankments with floating columns is investigated using a fully 3D coupled model. For an embankment at the working height corresponding to a post-consolidation polypropylene geotextile strain of about 5%, it is shown that the assumption of constant hydraulic conductivity and the failure to consider the viscous behaviour of geosynthetic reinforcement can underestimate time-dependent embankment deformations (including differential crest settlement and horizontal toe movement). The effects of factors including the foundation soil, reinforcement stiffness, column stiffness, column spacing, column type (floating and fully penetrating), and construction rate, on the time-dependent behaviour of column supported embankments are explored.  相似文献   

胜利油田孤东海堤外侧海底地形特征与变化分析     

冯守珍  刘建立  雷宁  仲德林 《海洋测绘》2006,26(6):38-41

K10(总理台)~K16海堤是孤东海堤重点防护岸段。通过2004年5月、2005年5月以及2005年12月三次测量资料和资料比较分析,K10~K16海堤近岸,距堤百米内水深一般小于5m,有些地段受水动力作用形成冲刷凹坑及沟槽。但海底地形变化在不同的地段是不同的,且冲淤变化差异明显。从K13~K16之间水深地形变化较微弱,K14附近局部略有淤积。K12附近及沿堤以南地段出现强侵蚀岸段,距离岸堤20m左右处,顺堤形成水深7m左右的强侵蚀地形沟槽,严重威胁孤东海堤的安全。因此,分析研究该段地形变化,可以为该段海堤防护提供最佳对策。  相似文献   

The Thames Embankment and the disciplining of nature in modernity   总被引：1，自引：0，他引：1  

STUART OLIVER 《The Geographical journal》2000,166(3):227-238

The embanking of the Thames was an emblematic stage in the construction of modernity's discourse of 'the natural', re-engineering the river as a concrete framing of nature between the embankment walls and a representational framing of the natural within an engineering ideology. The legitimacy of embanking's control was, therefore, about both physical mechanisms and a particular discourse of the natural, but the Thames embankments did not merely reflect modernity's discourse - they actively helped mould it. The creation of a discourse of embanking was slow and hesitant, the product of the interplay between the subsidiary discourses of urban improvement and sanitarianism, and an opposing discourse of tradition. When built, the embankments acted as a fixed, ordered boundary between the cultured nature of the drained, commodified land, and the regulated liveliness of the river. They acted literally and figuratively to sever culture from a nature that was enclosed and tamed by embankment walls.  相似文献   

Elastic settlements under linear surface pressures on rectangular areas     

Halil Murat Algin  Zeynep Algin 《国际地质力学数值与分析法杂志》2009,33(8):1087-1108

This paper presents the practical closed‐form solutions for elastic settlement under the linear full‐contact pressures on rectangular areas resting upon an elastic mass. The linear pressure distribution is mostly assumed in practice for the rectangular footing having biaxial bending. The equations presented here are determined by evaluating the integration of Steinbrenner's strain approximation based on the stress solutions from the Boussinesq equations. The presented formulae are validated to be used for the elastic settlement under any point of linear full‐contact loading, triangular and embankment types of pressure cases. In this respect, it represents a significant step forward in the understanding of elastic settlement and rotation under the practical loading cases. The presented solutions are concise and easy to use. The numerical examples are demonstrated and the resulting influence factors in graphical forms are presented for their practical use especially in the elastic settlement calculations of rectangular footing subjected to the biaxial bending. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Long-term thermal stability study of the typical embankment along the Qinghai-Tibet Railway in warm permafrost regions北大核心CSCD     

徐岳震  申明德  周志伟  马巍  李国玉 《冰川冻土》2022,44(6):1784-1795

Using the long-term ground temperature monitoring data of the permafrost zone along the Qinghai-Tibet Railway from 2006 to 2020,three types of typical roadbed structures were analyzed. Traditional embankment（TE）,U-shaped crushed rock embankment（UCRE）and crushed rock revetment embankment（CRRE）were included the three types of typical roadbed,which were selected to the long-term monitoring sections within the warm permafrost zones. The evolution of ground temperature field,mean annual ground temperature （MAGT）and annual maximum ground temperature（AMGT）in the depth range of 20 m under the embankment were analyzed and studied since 15 years of operation. The monitoring and analysis results show that：the growth rate of MAGT under the left and right shoulders of the TE is always higher than that of the same depth in the natural site. The MAGT under the UCRE is always lower than the natural site and always maintains a certain difference,whereas,the difference in ground temperature under the left and right shoulders is also not negligible. The MAGT of the left shoulder in the CRRE is not much different from that of the natural hole,while the MAGT of the right shoulder is always lower than that of the natural hole,and the differ in ground temperature between the left and right shoulders is smaller than that of the UCRE. The artificial permafrost table（APT）under the TE is always lower than that of in the natural site. Both the UCRE and CRRE,the APT in the left and right shoulders of them has been elevated into the embankment,and the differ of APT between the left and right shoulders is about 1. 0~1. 5 m. the differ of APT between the left and right shoulders in the CRRE is slightly lower than that of UCRE. Overall,because of the influence of thermal disturbance about engineering and climate warming,the TE in the warm permafrost zones cannot keep the thermal stability of permafrost under the embankment. Some active-cooling and reinforcement measures need to be taken. Both of the UCRE and CRRE,have a certain active-cooling effect on the permafrost under embankment,but the differ in ground temperature between the left and right shoulders still needs to be taken seriously. © 2022 Science Press (China).  相似文献   

江湖地质环境演变中的武汉市堤防历史与城市发展     

李国庆  张玉芬  李长安 《地质论评》2021,67(3):67040021-67040021

武汉位于长江与汉江交汇处,江、湖地质环境是造就武汉城市的基础,同时江河水患又是城市发展的主要制约因素。筑堤防洪是武汉城市建设的重中之重,武汉的城市发展史从某种程度上说就是堤防的修建史,是武汉城市发展的人地关系史。本文以武汉堤防修筑历史进程为主线,探讨了堤防建设的地质环境及对城市空间拓展和城市建设的意义。结果表明：修筑于北宋政和年间（公元1111 ~ 1118年）武昌的花蕊堤是武汉市最早的堤防,距今已有约900年的历史;明代以前为零星堤防建设阶段,主要为保护城廓安全,哪里遇险在哪里修堤,具有局部性、应对性特点。明代堤防兴建已带有很强的目的性和一定的系统性,特别是袁公堤的修建开启了武汉围垸发展的历史。清代是武汉堤防大发展时期,开始了较系统的堤防工程,奠定了武汉市堤防系统的基础,大量围垸的修建使武汉城市由沿河、沿江（天然堤）发展开始走向了内陆（围湖）发展的新阶段。民国时期,武汉市的堤防建设在清代的基础做了进一步的局部完善。武汉市的防洪堤防体系真正形成于新中国成立后的20世纪50年代,之后又不断地加固和加高,使之真正成为武汉市的安全保障工程;汉口的形成与发展完全依赖于堤防,城区的扩大大约经历了四个阶段,均是以四次堤防建设—袁公堤、汉口堡、京汉铁路堤、张公堤为前提的。堤防不仅是城市空间扩展的前提,又是城市建设的基础,民国以前武汉城区的主要街道大多数都依堤而建,平时以堤为街,汛期以街为堤,这是武汉城市建设和发展的显著特点。分别以袁公堤和张公堤为界,武汉堤防建设中的人地关系大致经历了三个阶段：“人类部分干预自然”维护生存阶段、“人为改造自然”谋求发展阶段和“人为控制自然”快速发展阶段。本研究可为地处洪泛区的城市地质调查提供借鉴。  相似文献   

共和-玉树高速公路多格茸段冻胀丘与公路路基的相互影响     

吴吉春  盛煜 《冰川冻土》2021,43(2):453-462

冻胀丘是土层中水分向冻结锋面大量迁移集聚,并且冻结膨胀使地面隆起呈丘状的一类冰缘地貌。冻胀丘的本质特征是存在纯冰核或高含冰地层,冻胀丘地表的隆起高度即代表了地下冰层的累计厚度,在工程建设中一般采用避让措施。在我国冻土区公路建设中,过去尚未遇到道路穿越冻胀丘的先例,正在建设中的青海省共和-玉树高速公路（简称共玉高速）在玛多县多格茸盆地横跨几个冻胀丘,对公路建成以后安全运营造成潜在威胁。以共玉高速建设里程K430+070处道路所跨的冻胀丘为例,基于地温监测数据和冻胀丘钻探资料,探讨公路建设对冻胀丘下覆冰层的影响及由此带来的路基稳定性问题。监测发现目前路基下多年冻土上限已经下降至冻胀丘高含冰地层位置,由于沥青路面的强吸热性,未来冻胀丘路段将发生持续沉降。如果多年冻土完全融化,该段路基有可能发展成热融湖塘。  相似文献