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| 1 | 基于降雨渗流场变化的三峡库区白水河滑坡变形机制与预测显示文摘白水河滑坡位于三峡大坝以西56 km,为三峡库区重点监测滑坡之一。自2003年9月被纳入二期专业监测点以来,该滑坡一直被严密监测。2007年汛期该滑坡曾出现险情,并发布蓝色与橙色预警。目前,通过对该滑坡的监测积累了大量的监测数据,包括:地表GPS监测点位移、地下水位、钻孔测斜、滑坡推力、大气降雨以及三峡水库水位等。根据近十年的野外监测数据,该滑坡自2003年以来一直持续变形,降雨与库水位变化造成白水河滑坡地下水位变化,进而影响其整体稳定性。在强降雨和库水位同时下降的极端条件下,滑坡有可能加速变形。本文利用加拿大Geo-Studio岩土仿真软件SEEP/W模块模拟白水河滑坡在降雨入渗作用下瞬态渗流场,量化分析了白水河滑坡坡体内孔隙水压力变化与大气降雨之间的关系,并使用SIGMA/W模块,将瞬态孔隙水压力分布运用于滑坡变形分析中,探讨了该滑坡地表变形幅度与降雨强度之间的关系,以期为极端天气下水库区松散堆积层滑坡稳定性和变形机理分析提供借鉴。 | 尚敏 徐鑫 Dave Chan 张国栋 梁鸿熙 | 2016 | 中国地质灾害与防治学报2016，27，2： | 20 |
| 2 | 循环脱吸湿与加卸载耦合作用下土体持水性能试验研究显示文摘土体所经历的干湿循环和应力历史,对其孔隙结构和持水性能影响明显。为进一步深入研究二者耦合作用的影响,开展了先竖向固结再循环脱吸湿以及先气压脱湿再反复竖向加卸载两种不同加载路径的水分变化测量试验,探索土样持水性能和变形能力的演化规律。研究结果表明:(1)脱湿与吸湿路径对比,土体的持水能力具有明显的差异性,且土体越密实,这种差异性越强烈;(2)随着脱吸湿循环次数的增加,土样的进气值略有增大,减湿段和吸湿段的斜率都会减小,但影响趋势随循环次数增多而减弱;(3)对于气压减湿后的非饱和土样,其前期固结压力随气压值增加而增大,而加卸载形成的滞回圈的面积却随之减小,土体的持水性能和变形能力也降低;(4)重塑土样从不同加载路径首次达到同一应力状态时,先固结再脱湿路径下土样的体积收缩更多,而先施加气压再加载路径下土样持水性能减弱的更多。 | 陈勇 苏剑 谈云志 CHAN Dave | 2019 | 岩土力学2019，40，8： | 13 |
| 3 | 库水循环加卸载条件下岸坡饱和土体变形特性试验研究显示文摘水库运行期水位每年周期性涨落,岸坡土体在库水循环加卸载作用下会发生不同程度的阶梯状变形。为探求循环加卸载对岸坡深部变形的诱发机理,本文以水库防洪限制水位以下岸坡土体为研究对象,在饱和土应力路径三轴试验过程中,控制非等向受压试样的孔隙水压力周期变化,模拟岸坡土体的水力-力学状态,实时测定土体的周期性变形特性及破坏特征。研究结果表明:等偏应力孔压循环加卸载过程中,试样剪应变为台阶式上升趋势,而体应变是循环的弹性变化;孔压持续增大造成试样破坏呈现脆变和剪胀的特征。最后,结合等偏应力孔压增大条件下粉质黏土的破坏特征与常规三轴剪切试验成果,对比两种应力路径下试样的有效应力比和剪应变的发展过程,分析了其强度差异的内在原因。 | 陈勇 韦双 Dave Chan | 2015 | 水利学报2015，46，5： | 10 |
| 4 | 基于孔隙水压力变化的三峡库区盐关滑坡破坏机制分析显示文摘2017年10月30日,位于秭归县归州镇香溪河右岸的盐关滑坡发生整体滑移破坏,成为近年来三峡库区为数不多的整体破坏变形的滑坡之一。根据现场应急调查,滑坡在不到3天的时间内经历了预警直至完全破坏的过程。本文以盐关滑坡为实例,根据滑坡失稳破坏特征结合有效应力原理提出了孔隙水压力变化速率条件下滑坡失稳破坏的模式,分析出滑坡体内的孔隙水压力对滑坡破坏的影响,最后通过有限元模拟软件予以验证。利用Geo-Studio岩土仿真软件SEEP/W模块模拟盐关滑坡在降雨入渗作用下的渗流场,结合滑坡变形期直至破坏时的实际库水位值计算出孔隙水压力随时间变化曲线,并且将所得结果应用到Slope/W模块,计算出滑坡的安全系数随时间的变化曲线,从而验证出滑坡失稳破坏的主要原因是滑坡内部土体在降雨和库水位的作用下达到饱和后,孔隙水压力激增所导致的。 | 尚敏 刘昱廷 DAVE Chan 廖芬 | 2021 | 工程地质学报2021，29，3： | 7 |
| 5 | Theoretical elastoplastic analysis for foundations with geosynthetic-encased columns显示文摘As a new technique in ground improvement, geosynthetic-encased columns (GECs) have promising applications in soft soil foundation. By assuming yielding occurs in the columns while the surrounding soil and the geosynthetic remain elastic, an elastoplastic analytical procedure for foundations improved by GECs is proposed. The radial stresses that the geosynthetic provides and the elastoplastic deformations of the foundation resting on a rigid base are derived. A comparison with finite element analysis shows that the proposed method is effective and can provide a reasonable prediction of a GEC's deformation. Subsequent parametric analysis indicates that higher geosynthetic stiffness leads to better performance of the composite foundation. The optimum length of encasement is related to the load acting on the foundation and the permissible vertical and radial displacements of the column. Moreover, as the dilation angle of the column increases, the settlement decreases, especially under high loading. The influence of the encasement is more significant in soils with smaller elastic modulus. | Yuan-yu DUAN Yi-ping ZHANG Dave CHAN Ya-nan YU | 2012 | Journal of Zhejiang University-Science A(Applied Physics & Engineering)2012，13，7： | 4 |
| 6 | Constitutive model for monotonic and cyclic responses of loosely cemented sand formations显示文摘This paper presents a model to simulate the monotonic and cyclic behaviours of weakly cemented sands.An elastoplastic constitutive model within the framework of bounding surface plasticity theory is adopted to predict the mechanical behaviour of soft sandstone under monotonic and cyclic loadings. In this model, the loading surface always passes through the current stress state regardless of the type of loading. Destruction of the cementation bonds by plastic deformation in the model is considered as the primary mechanism responsible for the mechanical degradation of loosely cemented sands/weak rock.To model cyclic response, the unloading plastic and elastic moduli are formulated based on the loading/reloading plastic and elastic moduli. The proposed model was implemented in FLAC2D and evaluated against laboratory triaxial tests under monotonic and cyclic loadings, and the model results agreed well with the experimental observations. For cyclic tests, hysteresis loops are captured with reasonable accuracy. | Mojtaba Rahimi Dave Chan Alireza Nouri | 2018 | Journal of Rock Mechanics and Geotechnical Engineering2018，10，4： | 3 |
| 7 | Prognostic significance of endoluminal ultrasound-defined disease length and tumor volume (EDTV) for patients with the diagnosis of esophageal cancer显示文摘 | Christopher P. Twine S. Ashley Roberts Wyn G. Lewis B. Vicki Dave Claire E. Rawlinson David Chan Mark Robinson Tom D. Crosby | 2010 | Surgical Endoscopy2010，，4： | 2 |
| 8 | 干湿循环次数对粉质黏土动力特性的影响研究与预测显示文摘库水位周期性涨落和水库诱发微震的耦合作用,对土体的变形特性和力学性质的影响不容忽视.采用电液伺服土动三轴试验系统,对经历不同干湿循环次数的饱和粉质黏土进行了不排水三轴动力试验,探讨干湿循环对动变形、动孔压、动弹性模量等动力特性的影响效应;并结合动力学参数指标的发展规律,建立与干湿循环次数和累积塑性应变发展有关的预测模型.研究结果表明:经历干湿循环后土体内部结构产生了不可逆的变化,随干湿循环次数的增加,累积塑性应变呈现增大趋势,残余孔压比、弹性模量均呈现减小特征,且干湿循环的影响趋势逐渐减小;建立的关于干湿循环次数相关的修正模型,能够相对准确地描述和预测历经多次干湿循环后土样的累积塑性应变、残余孔压比和动弹模的发展规律. | 陈勇 赵强 Dave Chan | 2017 | 三峡大学学报(自然科学版)2017，39，6： | 2 |
| 9 | Experimental study of the effect of fines content on dynamic compaction grouting in completely decomposed granite of Hong Kong显示文摘 | Wang Shanyong Dave Chan Ka Chi Lam | 2009 | Construction and Building Materials2009，23，3： | 1 |
| 10 | Regener- able DNA-functionalized hydrogels for ultrasensitive, instrument-free mercury(11) detection and removal in water显示文摘 | DAVE N CHAN M Y HUANG P J J | 2010 | J Am Chem Soc2010，132，12： | 1 |
| 11 | Consolidation of composite foundation improved by geosynthetic-encased stone columns显示文摘 | Yiping Zhang Dave Chan Yang Wang | 2011 | Geotextiles and Geomembranes2011，，： | 1 |
| 12 | Experimental study of the effect of fines content on dynamic compaction grouting in eompletely decomposed granite of Hong Kong显示文摘 | Wang Shanyong Chan Dave Ka Chi Lam | 2009 | Construction and Building Materials2009，23，： | 1 |
| 13 | 反复等向加卸载路径下粉质黏土变形特性研究显示文摘黏土的变形特性与应力路径密切相关,直接影响到相关工程的安全性。针对三峡库岸某路基边坡粉质黏土,采用应力路径控制试验系统,开展了两组等向固结应力状态下反复多次的加卸载试验,揭示了土体的体积变形发展规律,发现再固结过程呈现为一条先平缓后变陡的曲线,说明前期固结压力范围内的再加载也会产生不可恢复的塑性变形,且变形速率随加卸载循环次数逐渐减小。最后,结合试验曲线特点,建立了土体再固结系数与加卸载次数及应力状态相关的数学模型,能够较好的模拟反复等向加卸载条件下土样的体变特征,且可预测土体经历更多次加卸载循环中的次固结过程,为土体的持续塑性变形分析和预测提供参考。 | 陈勇 隆海鹏 曹玲 CHAN Dave | 2020 | 防灾减灾工程学报2020，40，2： | 0 |
| 14 | Relationship between rock macro-and micro-properties and wellbore breakout type显示文摘This study numerically investigates the effect of material micro-and macro-parameters on the failure mechanisms and geometry of a wellbore breakout.The analysis of the borehole breakout is essential in addressing wellbore stability,well completion,and sand production problems.The three-dimensional discrete element method(DEM)was used in the simulations.The numerical tool was used in numerical model simulations of drilling through sandstone in cubic samples at the laboratory scale subjected to pre-existing far-field stresses.Besides,a series of triaxial testing simulations were performed to relate the micromechanical parameters to the macromechanical material properties.The results showed that the geometry of the breakout is affected,among the material micro-parameters,by the particle contact modulus,bond normal and shear strengths,particle crushing strength,and particle size distribution.Further,it was found that the macro-parameters including Young’s modulus,friction and dilation angles,and uniaxial compression strength(UCS)also affect the type of breakout. | Hossein Rahmati Alireza Nouri Dave Chan Hans Vaziri | 2021 | Underground Space2021，6，1： | 0 |
| 15 | 库岸有限厚度粉质黏土冲蚀演化规律及预测显示文摘土体冲蚀流失是塌岸发展和库岸再造的重要诱发因素。为准确预测水流作用下岸坡土体流失进程,自主研制了能够实时精确量测土样质量变化的新型冲蚀试验装置,开展三峡库岸粉质黏土冲刷起动和冲蚀进程试验,分析有限厚度土体冲蚀演化规律和影响机制,并建立预测模型。结果表明:有限厚度土体的总冲蚀量随时间增加但增速逐渐趋缓,冲蚀速率逐渐衰减,且冲蚀速率及其衰减程度均与孔隙比或流速成正比;将反映密实度的孔隙比和反映剪切力的水流速度嵌入预测模型能较好地拟合粉质黏土冲蚀演化进程曲线。建立的有限厚度土体冲蚀进程预测模型,为水流冲刷作用下岸坡形态变化趋势预测研究提供参考。 | 陈勇 张书石 CHAN Dave | 2023 | 水科学进展2023，34，6： | 0 |
| 16 | Evaluation of numerical schemes for capturing shock waves in modeling proppant transport in fractures显示文摘In petroleum engineering, the transport phenomenon of proppants in a fracture caused by hydraulic fracturing is captured by hyperbolic partial differential equations(PDEs). The solution of this kind of PDEs may encounter smooth transitions, or there can be large gradients of the field variables. The numerical challenge posed in a shock situation is that high-order finite difference schemes lead to significant oscillations in the vicinity of shocks despite that such schemes result in higher accuracy in smooth regions. On the other hand, first-order methods provide monotonic solution convergences near the shocks,while giving poorer accuracy in the smooth regions.Accurate numerical simulation of such systems is a challenging task using conventional numerical methods. In this paper, we investigate several shock-capturing schemes.The competency of each scheme was tested against onedimensional benchmark problems as well as published numerical experiments. The numerical results have shown good performance of high-resolution finite volume methods in capturing shocks by resolving discontinuities while maintaining accuracy in the smooth regions. Thesemethods along with Godunov splitting are applied to model proppant transport in fractures. It is concluded that the proposed scheme produces non-oscillatory and accurate results in obtaining a solution for proppant transport problems. | Morteza Roostaei Alireza Nouri Vahidoddin Fattahpour Dave Chan | 2017 | Petroleum Science2017，14，4： | 0 |
| 17 | Numerical investigation of the hydraulic fracturing mechanisms in oil sands显示文摘This paper presents a numerical investigation of hydraulic fracturing in oil sands during cold water injection by considering the aspects of both geomechanics and reservoir fluid flow.According to previous studies,the low shear strengths of unconsolidated or weakly consolidated sandstone reservoirs significantly influence the hydraulic fracturing process.Therefore,classical hydraulic fracture models cannot simulate the fracturing process in weak sandstone reservoirs.In the current numerical models,the direction of a tensile fracture is predetermined based on in situ stress conditions.Additionally,the potential transformation of a shear fracture into a tensile fracture and the potential reorientation of a tensile fracture owing to shear banding at the fracture tip have not yet been addressed in the literature.In this study,a smeared fracture technique is employed to simulate tensile and shear fractures in oil sands.The model used combines many important fracture features,which include the matrix flow,poroelasticity and plasticity modeling,saturation-dependent permeability,gradual degradation of the oil sands as a result of dilative shear deformation,and the tensile fracturing and shear failure that occur with the simultaneous enhancement of permeability.Furthermore,sensitivity analyses are also performed with respect to the reservoir and geomechanical parameters,including the apparent tensile strength and cohesion of the oil sands,magnitude of the minimum and maximum principal stress,absolute permeability and elastic modulus of the oil sands and ramp-up time.All these analyses are performed to clarify the influences of these parameters on the fracturing response of the oil sands. | Siavash Taghipoor Morteza Roostaei Arian Velayati Atena Sharbatian Dave Chan Alireza Nouri | 2021 | Underground Space2021，6，2： | 0 |
| 18 | 周期加卸载条件在ABAQUS中的数值实施方法及验证显示文摘水库运行期水位每年周期性涨落,岸坡土体在库水周期加卸载作用下发生不同程度的阶梯状变形。为探求变形的诱发机理、揭示变形的发展规律,本文以参数简单且意义明确的统一硬化模型(UH模型)为基础,建立了该模型的增量关系,并借用ABAQUS软件的开发接口,添加该模型的UMAT子程序,从而建立土体在周期加卸载作用下的应力应变演化规律模拟方法。最后,对数值模拟方法和子程序进行了单元测试和试验成果验证,对比分析结论如下:开发的UH模型UMAT子程序是可行的,模拟结果与特殊应力路径下三轴试验中的有效应力变化与应变发展规律等吻合性较好。 | 陈勇 杨贝贝 韦双 Dave Chan | 2014 | 水利学报2014，45，S2： | 0 |
| 19 | 三峡库区白水河滑坡在降雨作用下变形分析显示文摘白水河滑坡位于三峡大坝以西56km,为三峡库区重点监测滑坡之一。自2003年9月被纳入二期专业监测点以来,该滑坡一直被严密监测。2007年汛期该滑坡曾出现险情,并发布蓝色与橙色预警。目前,通过对该滑坡的监测积累了大量的监测数据,包括:地表GPS监测点位移、地下水位、钻孔测斜、滑坡推力数据、大气降雨以及三峡水库水位数据。根据近10年的野外监测数据,该滑坡自2003年以来一直持续变形,降雨与库水位变化是影响白水河滑坡地下水位变化,进而影响其整体稳定性的主要因素。在强降雨和库水位同时下降的极端条件下,滑坡将有可能加速变形。通过利用加拿大Geo—Studio岩土仿真软件SEEP/W模块模拟白水河滑坡在降雨入渗作用下瞬态渗流场,量化分析了白水河滑坡坡体内孔隙水压力变化与大气降雨之间的关系,并使用SIG—MA/W模块,将瞬态孔隙水压力分布运用于滑坡变形分析中,从而探索了该滑坡地表变形幅度与降雨强度之间的关系,为极端天气下滑坡稳定性分析提供了指导性建议。 | 徐鑫 尚敏 Dave Chan 张国栋 梁鸿熙 | 2015 | 灾害与防治工程2015，0，1： | 0 |
| 20 | 加拿大总理保罗·马丁在加中贸易理事会2004年年会暨晚宴上的讲话显示文摘马丁先生于2003年12月12日接替担任加拿大总理达10年之久的克雷蒂安,成为加拿大第21任联邦总理。马丁总理的父亲老马丁,曾在皮尔逊、特鲁多等四届加拿大自由党政府中担任重要职务。老马丁曾经为推动加拿大承认中华人民共和国和加中建交作出过重要贡献:马丁总理非常重视发展对华关系,他在施政纲要中把中国列为优先发展加拿大对外关系的三个重点国家之一。马丁2003年12月11日在宣誓就任联邦总理的前夜,在加拿大首都渥太华亲切会见了来访的中华人民共和国总理温家宝,温总理成为马丁总理接待的第一个外国政府首脑。 | Dave Chan | 2004 | 重庆与世界2004，，12： | 0 |
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