This paper presents a dynamic modeling method to test and examine the minimum mass of pressurized pore-gas for triggering landslides in stable gentle soil slopes.A stable gentle soil slope model is constructed with a ...This paper presents a dynamic modeling method to test and examine the minimum mass of pressurized pore-gas for triggering landslides in stable gentle soil slopes.A stable gentle soil slope model is constructed with a dry cement powder core,a saturated clay middle layer,and a dry sand upper layer.The test injects H_(2)O_(2)solution into the cement core to produce new pore-gas.The model test includes three identical H_(2)O_(2)injections.The small mass of generated oxygen gas(0.07%of slope soil mass and landslide body)from the first injection can build sufficient pore-gas pressure to cause soil upheaval and slide.Meanwhile,despite the first injection causing leak paths in the clay layer,the generated small mass of gas from the second and third injections can further trigger the landslide.A dynamic theoretical analysis of the slope failure is carried out and the required minimum pore-gas pressure for the landslide is calculated.The mass and pressure of generated gas in the model test are also estimated based on the calibration test for oxygen generation from H_(2)O_(2)solution in cement powder.The results indicate that the minimum mass of the generated gas for triggering the landslide is 2 ppm to 0.07%of the landslide body.Furthermore,the small mass of gas can provide sufficient pressure to cause soil upheaval and soil sliding in dynamic analysis.展开更多
The understanding of rainfall-induced landslides on gentle, loose-fill slopes is limited in comparison to steep slopes. Hence, two physical model tests were conducted on silty sand slopes under continuous rainfall: on...The understanding of rainfall-induced landslides on gentle, loose-fill slopes is limited in comparison to steep slopes. Hence, two physical model tests were conducted on silty sand slopes under continuous rainfall: one on a bare slope and the other on a slope planted with ryegrass. The slope angle of 25° is much lower than the internal friction angle of slope material (34.3°), which makes the model test fall well into the category of gentle slope. For the initially unsaturated bare slope, a rainfall event with return period of 18 years could trigger a rapid and retrogressive global sliding, which differs from previous findings that gentle slopes would only experience shallow failure. A sudden increase in pore-water pressure was simultaneously observed, which might be generated by the wetting-induced collapse of unsaturated loose soil. On the other hand, the stability of the slope with grass plantation was significantly enhanced, and it was able to withstand rainfall event more severe than those with a return period of 100 years, with only minimal deformation. The results suggest that the gain in shear strength due to ryegrass roots surpasses the additional sliding force caused by the increased water retention capability. Additionally, it is found that the abrupt change in pore pressure was no longer indicative of slope failure in the case of the grass-reinforced slope.展开更多
针对目标在形状、外观和光照条件发生较大变化时产生的检测率低的问题,以牛体检测为例提出了基于Gentle AdaBoost算法的牛体检测。利用bag of features(BOF)的思想创建特征词典,然后通过词典对牛体目标进行特征提取,最后通过Gentle AdaB...针对目标在形状、外观和光照条件发生较大变化时产生的检测率低的问题,以牛体检测为例提出了基于Gentle AdaBoost算法的牛体检测。利用bag of features(BOF)的思想创建特征词典,然后通过词典对牛体目标进行特征提取,最后通过Gentle AdaBoost算法对训练集的BOF特征向量进行训练分类,获得目标对象和场景的分类模型。实验结果表明,该算法训练的检测器在牛体目标存在光照不均匀、形变时均可实现可靠的检测。展开更多
Characteristics of soil erosion change along a long slope in the gentle hilly areas in black soil region in Northeast China are discussed. A simplified slope model based on segments was used to analyze the runoff data...Characteristics of soil erosion change along a long slope in the gentle hilly areas in black soil region in Northeast China are discussed. A simplified slope model based on segments was used to analyze the runoff data and soil erosion data observed between 2003 and 2004 over 10 field plots with different slope length in Heshan Farm, Heilongjiang Province. We found that soil erosion rate over long slopes in the black soil region changed alternatively along the slope and creates alternative zones of intensive erosion and week erosion.The exact place of each zone is different for different rainfall conditions. In a year with less and mild precipitation, rill cannot happen within the top 50 m, while in a year with large and intensive precipitation, rill can be formed starting even at 15 m from the top of the slope.展开更多
Seismic sedimentology is a new frontier inter-discipline subject, and shows good prospect and potentiality in reservoir deposition research with seismic data and geophysics technologies. We made seismic sedimentology ...Seismic sedimentology is a new frontier inter-discipline subject, and shows good prospect and potentiality in reservoir deposition research with seismic data and geophysics technologies. We made seismic sedimentology research of shallow sea area, gentle slope belt of Chengning （埕宁） uplift, Bohalwan （渤海湾） basin. In shallow sea area with sparse well coverage, it was difficult to characterize the reservoir architecture with the traditional method based on wells. A new method to resolve the above problems is built： （1） information on plane and in section is inter-ealibrated with each other; （2） recognize the isochronic surfaces by frequency decomposition and interpret the depositional character with technology of stratal slicing; （3） make a comprehensive research with the stratal slice interpreta- tion and the dissection of well group. The depositional model of this area is built and used in the architecture analysis of area without wells. The architecture description reveals that the sedimentary character of pan-connection sand bodies in braided rivers is the reason for high water cut of the new horizontal wells. .展开更多
The effects of slope surface material, slope gradient, block shape, and block mass conditions on rockfall rolling velocity were estimated with orthogonal test approach. Visual analysis shows that the importance of the...The effects of slope surface material, slope gradient, block shape, and block mass conditions on rockfall rolling velocity were estimated with orthogonal test approach. Visual analysis shows that the importance of the factors is slope surface material > slope gradient > block shape > block mass. All the factors except block mass have the F value greater than the critical value, suggesting that these three factors are the key factors affecting the rockfall rolling velocity. Factor interaction analysis shows that the effect of the slope gradient relies largely on the slope surface conditions, and the block shape has little influence if the slope gradient is larger than a critical value. An empirical model considering the three key factors is proposed to estimate the rolling velocity, of which the error is limited to 5% of the testing value. This model is validated by 73 field tests, and the prediction shows excellent correlation with the site test. Thus, this analysis can be used as a tool in the rockfall behavior analysis.展开更多
Potential tsunami generated in the Okinawa Trench or the Manila Trench may attack the southeast coast of China. The continental shelves with extremely gentle slope in the China Seas affect the evolvement of tsunami wa...Potential tsunami generated in the Okinawa Trench or the Manila Trench may attack the southeast coast of China. The continental shelves with extremely gentle slope in the China Seas affect the evolvement of tsunami waves. In this paper, we carry out the simulation of tsunami propagation based on the fully nonlinear and highly dispersive Boussinesq model, which could describe the nonlinearity and dispersion of water waves quite well. So the undulation characters could be well presented. In terms of the real topographies of the East China Sea and the South China Sea, we take some typical profiles to simulate the hypothetical tsunamis generated in the Okinawa Trench and the Manila Trench. Different waveforms in the near shore regions are obtained. The N-shape tsunami waves will evolve into long wave trains, undular bores or solitons near the coastal area. The numerical results of the near shore waveform provide essential conditions for the further studies of tsunami runup and inundation.展开更多
This paper presents a new method for the correct selection of mining methods and pre-diction of main technological and economic indexes of the face in the gentle inclined thick seams with the application of the artifi...This paper presents a new method for the correct selection of mining methods and pre-diction of main technological and economic indexes of the face in the gentle inclined thick seams with the application of the artificial neural network theory and the expert system. The theory anal- ysis and calculating results indicate that the method is reliable, practical and precise. This method has strongly capabilities of self-study and non-linear dynamic data process. It is expected to be widely applied in the policy decision and prediction of mining technology in coal mine.展开更多
基金supported by grants from the Research Grant Council of the Hong Kong Special Administrative Region,China(Project No.HKU 17207518).
文摘This paper presents a dynamic modeling method to test and examine the minimum mass of pressurized pore-gas for triggering landslides in stable gentle soil slopes.A stable gentle soil slope model is constructed with a dry cement powder core,a saturated clay middle layer,and a dry sand upper layer.The test injects H_(2)O_(2)solution into the cement core to produce new pore-gas.The model test includes three identical H_(2)O_(2)injections.The small mass of generated oxygen gas(0.07%of slope soil mass and landslide body)from the first injection can build sufficient pore-gas pressure to cause soil upheaval and slide.Meanwhile,despite the first injection causing leak paths in the clay layer,the generated small mass of gas from the second and third injections can further trigger the landslide.A dynamic theoretical analysis of the slope failure is carried out and the required minimum pore-gas pressure for the landslide is calculated.The mass and pressure of generated gas in the model test are also estimated based on the calibration test for oxygen generation from H_(2)O_(2)solution in cement powder.The results indicate that the minimum mass of the generated gas for triggering the landslide is 2 ppm to 0.07%of the landslide body.Furthermore,the small mass of gas can provide sufficient pressure to cause soil upheaval and soil sliding in dynamic analysis.
基金National Key R&D Program of China(2021YFC3001000)the National Natural Science Foundation of China(52239008,52108311,and 52025094)the Shenzhen Science and Technology Program(KQTD20210811090112003 and GXWD20231130125225001)for financial supports.
文摘The understanding of rainfall-induced landslides on gentle, loose-fill slopes is limited in comparison to steep slopes. Hence, two physical model tests were conducted on silty sand slopes under continuous rainfall: one on a bare slope and the other on a slope planted with ryegrass. The slope angle of 25° is much lower than the internal friction angle of slope material (34.3°), which makes the model test fall well into the category of gentle slope. For the initially unsaturated bare slope, a rainfall event with return period of 18 years could trigger a rapid and retrogressive global sliding, which differs from previous findings that gentle slopes would only experience shallow failure. A sudden increase in pore-water pressure was simultaneously observed, which might be generated by the wetting-induced collapse of unsaturated loose soil. On the other hand, the stability of the slope with grass plantation was significantly enhanced, and it was able to withstand rainfall event more severe than those with a return period of 100 years, with only minimal deformation. The results suggest that the gain in shear strength due to ryegrass roots surpasses the additional sliding force caused by the increased water retention capability. Additionally, it is found that the abrupt change in pore pressure was no longer indicative of slope failure in the case of the grass-reinforced slope.
文摘针对目标在形状、外观和光照条件发生较大变化时产生的检测率低的问题,以牛体检测为例提出了基于Gentle AdaBoost算法的牛体检测。利用bag of features(BOF)的思想创建特征词典,然后通过词典对牛体目标进行特征提取,最后通过Gentle AdaBoost算法对训练集的BOF特征向量进行训练分类,获得目标对象和场景的分类模型。实验结果表明,该算法训练的检测器在牛体目标存在光照不均匀、形变时均可实现可靠的检测。
基金National Basic Research Program of China, No.2007CB407207Knowledge Innovation Project of Institute of Geographic Sciences and Natural Resources Research,CAS,No.CXIOG-A04-10the support from CAS through its "One Hundred Talent" program
文摘Characteristics of soil erosion change along a long slope in the gentle hilly areas in black soil region in Northeast China are discussed. A simplified slope model based on segments was used to analyze the runoff data and soil erosion data observed between 2003 and 2004 over 10 field plots with different slope length in Heshan Farm, Heilongjiang Province. We found that soil erosion rate over long slopes in the black soil region changed alternatively along the slope and creates alternative zones of intensive erosion and week erosion.The exact place of each zone is different for different rainfall conditions. In a year with less and mild precipitation, rill cannot happen within the top 50 m, while in a year with large and intensive precipitation, rill can be formed starting even at 15 m from the top of the slope.
基金supported by the National Natural Science Foundation of China (No. 40872094)the Natural Science Foundation of Shandong Province (No. Z2008E01)
文摘Seismic sedimentology is a new frontier inter-discipline subject, and shows good prospect and potentiality in reservoir deposition research with seismic data and geophysics technologies. We made seismic sedimentology research of shallow sea area, gentle slope belt of Chengning （埕宁） uplift, Bohalwan （渤海湾） basin. In shallow sea area with sparse well coverage, it was difficult to characterize the reservoir architecture with the traditional method based on wells. A new method to resolve the above problems is built： （1） information on plane and in section is inter-ealibrated with each other; （2） recognize the isochronic surfaces by frequency decomposition and interpret the depositional character with technology of stratal slicing; （3） make a comprehensive research with the stratal slice interpreta- tion and the dissection of well group. The depositional model of this area is built and used in the architecture analysis of area without wells. The architecture description reveals that the sedimentary character of pan-connection sand bodies in braided rivers is the reason for high water cut of the new horizontal wells. .
基金supported by the National Science Foundation of China (Grant No. 41572302)the Funds for Creative Research Groups of China (Grant No. 41521002)
文摘The effects of slope surface material, slope gradient, block shape, and block mass conditions on rockfall rolling velocity were estimated with orthogonal test approach. Visual analysis shows that the importance of the factors is slope surface material > slope gradient > block shape > block mass. All the factors except block mass have the F value greater than the critical value, suggesting that these three factors are the key factors affecting the rockfall rolling velocity. Factor interaction analysis shows that the effect of the slope gradient relies largely on the slope surface conditions, and the block shape has little influence if the slope gradient is larger than a critical value. An empirical model considering the three key factors is proposed to estimate the rolling velocity, of which the error is limited to 5% of the testing value. This model is validated by 73 field tests, and the prediction shows excellent correlation with the site test. Thus, this analysis can be used as a tool in the rockfall behavior analysis.
基金supported by the National Natural Science Foundation of China (11202130 )the Doctoral Program Foundation of Higher Education (20060248046)
文摘Potential tsunami generated in the Okinawa Trench or the Manila Trench may attack the southeast coast of China. The continental shelves with extremely gentle slope in the China Seas affect the evolvement of tsunami waves. In this paper, we carry out the simulation of tsunami propagation based on the fully nonlinear and highly dispersive Boussinesq model, which could describe the nonlinearity and dispersion of water waves quite well. So the undulation characters could be well presented. In terms of the real topographies of the East China Sea and the South China Sea, we take some typical profiles to simulate the hypothetical tsunamis generated in the Okinawa Trench and the Manila Trench. Different waveforms in the near shore regions are obtained. The N-shape tsunami waves will evolve into long wave trains, undular bores or solitons near the coastal area. The numerical results of the near shore waveform provide essential conditions for the further studies of tsunami runup and inundation.
文摘This paper presents a new method for the correct selection of mining methods and pre-diction of main technological and economic indexes of the face in the gentle inclined thick seams with the application of the artificial neural network theory and the expert system. The theory anal- ysis and calculating results indicate that the method is reliable, practical and precise. This method has strongly capabilities of self-study and non-linear dynamic data process. It is expected to be widely applied in the policy decision and prediction of mining technology in coal mine.
