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Yi Qun Tang Xingwei Ren Bin Chen Shoupeng Song Jian Xiu Wang Ping Yang 《Environmental Earth Sciences》2012,66(7):1809-1816
Since the mid-1990s, multi-storied buildings, high-rise buildings and skyscrapers have been emerging due to the new round of great-scale development on the soft-soil littoral. Land subsidence in soft-soil areas caused by engineering environmental effect, especially by construction of high-dense building groups, attracts more and more attention. The plot ratio may be one of the most important factors on engineering-induced land subsidence. Thus, three geotechnical centrifugal model tests were conducted under three conditions of different plot ratios to study the ground settlement mechanism of high-dense building groups in soft-soil territory. It is concluded that the subsidence superimposition effect is obvious in the central area of high-dense building groups; the settlement increases with the growth of plot ratio. The urban planning department should take this subsidence situation into account when determining the construction plot ratio to utilize the earth more aptly and safely. 相似文献
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Jian-Xiu Wang Bo Feng Li-Sheng Hu Yi-Qun Tang Xue-xin Yan Han-mei Wang Jin-bao Liu 《Environmental Earth Sciences》2013,69(1):93-102
The restrictions of the geo-environment are often ignored in urban planning, thereby directly causing a variety of geological hazards, including large areas of land subsidence in soft soil area. Based on the control objective of land subsidence, the geo-environmental capacity of ground buildings (GECGB) is defined. The relationship between floor area ratio (FAR) and land subsidence in Shanghai, China is analyzed. The results illustrate that land subsidence increases as FAR increases, and that the engineering environmental effect of the high-rise building group is the main factor affecting land subsidence in Shanghai, China. Hayashi’s Quantification Theory type I is selected to evaluate the GECGB of four typical areas in Shanghai. The prediction model is established based on existing background materials and the GECGB expressed by allowable FAR of the four typical areas are calculated. The evaluation approach promoted in this paper can be applied in urban planning to control the land subsidence induced by dense high-rise buildings. 相似文献
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The engineering characteristics of soils are controlled by the state of the microstructure of soils to a great extent. With
the withdrawal of groundwater controlled reasonably, the engineering-environmental effect of the high-rise building group
becomes the main cause of land subsidence in Shanghai. This paper studied the microstructure of each soil layer under the
building loads in the centrifuge model by the scanning electron microscopy and the mercury intrusion porosimetry (MIP) for
qualitative analysis and quantitative analysis, respectively. The shape, size and contact condition of the basic unit of the
soil microstructure were analyzed. The pore structure of each soil layer was studied by MIP, and the pore distribution of
each soil layer was studied by the fractal theory. The ink-bottle effect exists in the intrusion stage in the MIP test. There
are four different fractal dimensions for silty clay of layer No. 4 and clayey soil of layer No. 8 and three different fractal
dimensions for silty sand of layer No. 7 and layer No. 9. The micro and macro mechanisms of land subsidence caused by the
high-rise building group were analyzed. 相似文献
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针对地下水埋深较浅地区,由高层建筑荷载引起的土体变形问题,以比奥固结理论为基础,结合土体非线性流变理论,将土体本构关系推广到黏弹塑性;同时考虑土体力学参数及水力参数的动态变化关系,建立了高层建筑荷载引发地面沉降与隆起变形的三维有限元数值模型,详细研究了高层建筑荷载影响下的土体变形特征及此过程中土体力学参数及水力学参数的变化特征。结果表明：由高层建筑荷载引起的地面沉降呈现漏斗状,以建筑物中心为漏斗中心,高层建筑荷载施加初期,高层建筑周围出现隆起,到达最大值后隆起逐渐消失;高层建筑底部浅层土体孔隙度、渗透系数及泊松比均呈现缓慢减小趋势,弹性模量呈现缓慢增大趋势;而高层建筑周围浅层土体的孔隙度、渗透系数及泊松比呈现先增大后减小的变化趋势,弹性模量则呈现先减小后增大的变化趋势;高层建筑影响区域浅部土体参数的变化趋势与土体的回弹及压缩有关。 相似文献
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为了准确预测由高层建筑引发土体应力场和渗流场变化而导致的地面沉降,以比奥固结理论为基础,结合土体非线性流变理论,将比奥固结理论中的本构关系拓展到黏弹塑性,并考虑了土体孔隙度、渗透系数及变形参数随有效应力的动态变化关系。以河北省沧州市为例,建立了沧州市高层建筑荷载、地下水渗流与土体变形三维流固全耦合数学模型。在对模型进行识别、验证的基础上,模拟预测了沧州市在地下水停采、仅存在高层建筑荷载的影响下,从2010年12月底到2025年12月底逐年的各含水层组地下水流场变化特征和地面沉降发展趋势。结果表明：沧州市由高层建筑荷载引发的最大地面沉降量为40.57 mm,最大地面沉降速率为2.7 mm/a,位于沧州市区。 相似文献
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Groundwater exploitation has been regarded as the main reason for land subsidence in China and thus receives considerable attention from the government and the academic community.Recently,building loads have been identified as another important factor of land subsidence,but researches in this sector have lagged.The effect of a single building load on land subsidence was neglected in many cases owing to the narrow scope and the limited depth of the additional stress in stratum.However,due to the superposition of stresses between buildings,the additional stress of cluster loads is greater than that of a single building load under the same condition,so that the land subsidence caused by cluster loads cannot be neglected.Taking Shamen village in the north of Zhengzhou,China,as an example,a finite-difference model based on the Biot consolidation theory to calculate the land subsidence caused by cluster loads was established in this paper.Cluster loads present the characteristics of large-area loads,and the land subsidence caused by cluster loads can have multiple primary consolidation processes due to the stress superposition of different buildings was shown by the simulation results.Pore water migration distances are longer when the cluster loads with high plot ratio are imposed,so that consolidation takes longer time.The higher the plot ratio is,the deeper the effective deformation is,and thus the greater the land subsidence is.A higher plot ratio also increases the contribution that the deeper stratigraphic layers make to land subsidence.Contrary to the calculated results of land subsidence caused by cluster loads and groundwater recession,the percentage of settlement caused by cluster loads in the total settlement was 49.43%and 55.06%at two simulated monitoring points,respectively.These data suggest that the cluster loads can be one of the main causes of land subsidence. 相似文献
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The Characteristics and Causes of Land Subsidence in Tanggu Based on the GPS Survey System and Numerical Simulation 总被引：1，自引：0，他引：1
Land subsidence is a severe hazard threatening Tanggu, a flat lowland area, and evidences of land subsidence can be seen throughout the city. A new reasonable GPS network was set up in this area from 2008 to 2010. The monitoring data show that land subsidence was serious and two main subsidence cones were obviously formed in the region. One emerged at Hujiayuan, with the maximum rate reaching 60 mm/a, and the influence region enlarged prominently from 2005 to 2010. The other one occurred at Kaifaqu, which became obvious only after 2005, and it showed a decreasing tendency with time. To analyze the causes of ground settlement, a correlation between groundwater withdrawal and land subsidence was firstly made. The results confirmed that over-exploitation of groundwater was the major cause for the severe settlement in Hujiayuan. Meanwhile, the subsidence of Kaifaqu was also related to groundwater withdrawal before 2005. However, the relationship became unconspicuous after 2005. To find the cause of this abnormity, a three-dimensional finite element numerical model, coupled with groundwater flow and subsidence, was built. The simulation results indicate that the subsidence induced by high-rise buildings is serious, but the affected range is limited and it also shows a decreasing trend with time, corresponding to the subsidence characteristics at Kaifaqu. Therefore, more attention should be paid to this hazard induced by engineering construction besides groundwater withdrawal, as more high-rise buildings are under construction in Tanggu. 相似文献
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Application of grey theory-based model to prediction of land subsidence due to engineering environment in Shanghai 总被引：7，自引：0，他引：7
Yi-Qun Tang Zhen-Dong Cui Jian-Xiu Wang Li-Ping Yan Xue-Xin Yan 《Environmental Geology》2008,55(3):583-593
Land subsidence is a common geological hazard. The long-term accumulation of land subsidence in Shanghai has caused economic
loss to the city. Since the 1990s, the engineering structures have become a new cause of land subsidence. Many factors affect
the process of land subsidence. Although such a process cannot be explicitly expressed by a mathematical formula, it is not
a “black box” whose internal structure, parameters, and characteristics are unknown. Therefore, the grey theory can be applied
to the prediction of land subsidence and provides useful information for the control of land subsidence. In this paper, a
grey model (GM) GM (1, 1) with unequal time-intervals was used to predict the subsidence of a high-rise building in the Lujiazui
area of Shanghai, and the results were compared with the monitored data. The prediction of subsidence was also corroborated
by laboratory tests and the results were compared with measured data and the predicted data by the adaptive neuro-fuzzy inference
system (ANFIS). It is found that the GM (1, 1) with unequal time-intervals is accurate and feasible for the prediction of
land subsidence. 相似文献
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为了准确分析建筑荷载和地下水开采对地面沉降的影响,为吴江盛泽地区科学防控地面沉降提供决策依据,基于比奥固结和地下水渗流理论,建立了建筑荷载和地下水开采与地面沉降三维全耦合有限元数值模型,分别模拟预测了在建筑荷载单独作用、地下水开采单独作用及建筑荷载和地下水开采叠加作用三种情况下,2015-09-01—2030-08-31盛泽地区逐年地面沉降变化趋势。结果表明,建筑荷载对盛泽地区地面沉降的影响大于地下水开采。第Ⅰ黏性土弱含水层和第I承压含水层分别为建筑荷载和地下水开采单独作用下的主压缩层,单层压缩量占比分别为43.04%和54.06%;第Ⅰ承压含水层及其上覆第Ⅰ黏性土弱含水层是二者叠加作用引发土体变形的主压缩层,其压缩量之和占总压缩量的71.30%。建筑荷载和地下水开采单独作用下引发的地面沉降量的线性叠加之和大于二者叠加作用下引发的地面沉降量,建筑荷载和地下水开采叠加作用引发的地面沉降具有耦合效应。 相似文献
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古潜山是中国水热型地热的主要富集区,具有分布广、潜力大、开发利用条件好等特点,同时也是中国地面沉降相对严重的地区。廓清古潜山区地面沉降的影响机制是区域地下水资源以及地热资源的合理规划与开发利用的基础。本文从地面沉降的机理出发,以雄安新区为例,从第四系厚度、黏性土含量、水位变化、土体固结性、地下水的越流补给以及地下水开采量6个方面分析了对地面沉降的影响,认为雄安新区地面沉降的发生主要受第四纪地层中地下水的超采和砂岩热储的采灌不均衡两个因素的影响,其中地下水超采是地面沉降的主要因素,砂岩热储层的无序开发是诱发地面沉降的次要因素,碳酸盐岩热储的开发尽管会造成热储压力的下降,但受碳酸盐岩压缩性能的影响储层不会产生明显的压缩变形。研究结果可以为新区地面沉降的防治及能源规划提供支撑。 相似文献
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The effect of clay dehydration on land subsidence in the Yun-Lin coastal area, Taiwan 总被引：1，自引：2，他引：1
The smectite dehydration theory developed by Ransom and Helgeson was applied for simulation of land subsidence in the Yun-Lin
coastal area, Taiwan. The volumetric reduction of smectite clay at equilibrium state was computed by assuming that the dehydration
of interlayer water in smectite clay can be described with a regular solid solution reaction. By using the in situ stratigraphic
data collected from the subsidence monitoring wells in the simulated area, the amounts of land subsidence caused by smectite
dehydration in three scenarios with pressure variation were calculated. The results indicate that significant amounts of land
subsidence can be attributed to smectite dehydration. This finding reveals that smectite dehydration is of importance for
assessment and prediction of land subsidence. Additionally, the results also indicate the overburden weight has a larger effect
on clay dehydration than the effective stress change resulting from over-pumping, although both of them induce relatively
minor variations on land subsidence.
Received: 23 February 2000 · Accepted: 23 March 2000 相似文献
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地面沉降是北京平原区主要地质灾害之一。文中采用永久散射体差分干涉测量(PS-InSAR)技术获取平原区地面沉降空间分布特征,基于GIS空间分析平台,将多种地面沉降影响因素分别与PS-InSAR获取的地面沉降场形变信息进行耦合研究,查明地面沉降与多种影响因素之间的响应关系。研究发现:(1)北京市地面沉降发育较为严重的地区主要出现在平原区东部、北部以及南部等地,存在多个沉降中心,最大沉降速率达到152mm/a,区域不均匀沉降现象明显,并且有连成一片的趋势。(2)地面沉降分布具有明显的构造控制特性,沉降区多位于几大活动断裂交接部位的沉积凹陷地区,与第四纪沉积凹陷十分吻合。地面沉降的发展趋势与活动断裂的走向具有明显的对应关系,在有活动断裂通过的区域,地面沉降剖面线上表现出明显的转折或突变,断裂两侧区域不均匀沉降十分明显。(3)地面沉降分层沉降量与对应层位上黏性土占比呈正比例关系,其空间分布特征及变化趋势与平原区的地层结构及可压缩黏性土层厚度具有很好的一致性,沉降范围整体由北西向的单一结构区向南东方向的多层结构区扩张。沉降速率大于50 mm/a的沉降区大多分布在黏性土层厚度大于100 m的地区,几大沉降中心与黏性土层厚度较大地区吻合较好。(4)第二承压含水层(顶底板埋深100~180 m)地下水开采对地面沉降影响最大,沉降中心与该层位地下水位降落漏斗区高度吻合,是地面沉降的主要贡献层位。 相似文献
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改进的灰色Verhulst GM(1,1)建筑物沉降模型 总被引：1，自引：0，他引：1
刘玉成 《中国地质灾害与防治学报》2006,17(4):61-63
造成建筑物的沉降因素是复杂多样,沉降机理与过程是非线性的,从理论上给出符合实际的建筑物沉降公式很困难,许多安全等级很高的重要建筑物在施工期间均需进行沉降观测,以保证建筑物的安全而及时修改设计。根据建筑物沉降观测数据列特征,综合分析了影响建筑物沉降的因素,应用灰色理论关于连续非线性数据列的建模方法,经过二次拟合,建立了能描述高层建筑沉降过程的非等间距灰色Verhulst GM(1,1)模型。该模型经重庆地区某高层建筑沉降观测实例验证,能较准确预测建筑物的沉降过程和最终沉降量。表明利用少数高层建筑沉降的观测数据建立非等间距的灰色Verhulst GM(1,1)模型能较准确模拟建筑物沉降过程和预测最终沉降量,其建模方法较简单、精度高,具有一定的实用性。 相似文献
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天津市地面沉降的特征及其危害 总被引：3，自引：0，他引：3
天津是我国北方地面沉降最严重的城市之一,40余年的持续沉降不仅直接造成对安全高程、市政基础设施、房屋等建筑物的破坏,而且还通过安全高程的损失加剧了其他自然灾害的发生,使社会经济遭受严重损失.正确认识天津市地面沉降的特点及其危害,有利于控沉部门制定科学而有效的地面沉降减灾防灾政策和措施.基于对地面沉降所造成的危害分析和阐述,认为不合理开发地下流体资源是导致天津市地面沉降的主要原因,并提出相应预防和治理地面沉降的对策. 相似文献
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煤矿采空区场地建筑适宜性工程地质研究方法 总被引：5，自引：0，他引：5
简述了煤矿采空区场地存在的工程地质问题；提出了查明采空区场地工程地质条件的现场勘察和室内模拟研究方法。并结合采空区活化特点，对采空区场地建筑适宜性作了分析；提出了地基处理和建筑物防护措施 相似文献