Fine unsaturated soils are used in many applications, particularly in road infrastructure and in construction. These materials undergo deformations according to the stresses to which they are subjected. The purpose of...Fine unsaturated soils are used in many applications, particularly in road infrastructure and in construction. These materials undergo deformations according to the stresses to which they are subjected. The purpose of this paper is to study the influence of hydromechanical stresses on the behavior of low swelling soils compacted at low water content in accordance with the French standard GTR 92 (Guide des Terrassements Routiers). Then, various experimental tests on an oedometer were carried out in the laboratory. Two types of low swelling soil sampled in Nasso on the outskirts of the town of Bobo Dioulasso (Burkina Faso) were used. After shuffling, each sample was moistened to its optimum water content and then compacted to 90% and 95% of its optimum density. Behavior tests show that these soils deform very little when subjected to hydromechanical stresses. However, these deformations are swelling in nature for low mechanical stresses and when the stresses are high, they tend to collapse. When these soils are subjected to a vertical stress of 420 kPa, the primary consolidation time is of the order of one minute for NH<sub>2</sub> (a silty soil) and about ten minutes for NH<sub>3 </sub>(a silty-clayed soil).展开更多
By testing soil organic matter （SOM） contents, soil water contents （SWC） within low suctions, and saturated infiltration rates of samples taken from east slope of Gongga Mountain of China, the enhancive effects of...By testing soil organic matter （SOM） contents, soil water contents （SWC） within low suctions, and saturated infiltration rates of samples taken from east slope of Gongga Mountain of China, the enhancive effects of SOM contents on SWC within low suctions and saturated infiltration rates were quantified. The simulated functions might be applied on regional experience forest-hydrology model. The improving function of protecting forest floor and increasing SOM contents on forest ecosystem hydrological effects were also embodied.展开更多
In this paper, we proposed a new method that has been developed based on the surface soil moisture content(SSMC) to more efficiently calculate the groundwater evaporation in variably saturated flow modeling. In this m...In this paper, we proposed a new method that has been developed based on the surface soil moisture content(SSMC) to more efficiently calculate the groundwater evaporation in variably saturated flow modeling. In this method, the empirical formula to calculate evaporation was modified and the value of the formula varies from zero to one as a closed interval. In addition, the simulation code for calculating the groundwater evaporation based on the SSMC method was incorporated into the EOS9 module of Tough2, a variably saturated flow modeling code. Finally, two numerical tests and a case simulation were conducted to verify the feasibility and accuracy of the SSMC method. Simulation results indicate that the SSMC method is capable of appropriately simulating the characteristics of water flow in vadose zone and the amount of evaporation with the variable water table. And such results are in coincidence with the value calculated by the logistic function method, and fit well with the measured data globally rather than locally.展开更多
针对合水油田庄XX区长8储层油井“微裂缝+高渗带”水淹现状,结合储层地质特点、动态开发特征等因素,开展堵水和原层补孔压裂技术相结合的储层改造试验。庄XX区长8平均油层厚度17.9 m,平均射孔段6.4 m,储层整体打开程度较低,为35.7%,这...针对合水油田庄XX区长8储层油井“微裂缝+高渗带”水淹现状,结合储层地质特点、动态开发特征等因素,开展堵水和原层补孔压裂技术相结合的储层改造试验。庄XX区长8平均油层厚度17.9 m,平均射孔段6.4 m,储层整体打开程度较低,为35.7%,这为“堵水和原层补孔压裂”提供了基础条件。2019—2021年,堵水压裂实践表明,在升压1~2 MPa、酚醛树脂体系、堵剂用量650 m 3条件下,效果较好,原层压裂改造参数为小排量1.6~1.8 m 3/min、低砂比20%、低砂量16~20 m 3,可达到控水增油目的。此方法充分发挥了油藏潜力,为同类油藏高含水井治理提供了借鉴与指导。展开更多
文摘Fine unsaturated soils are used in many applications, particularly in road infrastructure and in construction. These materials undergo deformations according to the stresses to which they are subjected. The purpose of this paper is to study the influence of hydromechanical stresses on the behavior of low swelling soils compacted at low water content in accordance with the French standard GTR 92 (Guide des Terrassements Routiers). Then, various experimental tests on an oedometer were carried out in the laboratory. Two types of low swelling soil sampled in Nasso on the outskirts of the town of Bobo Dioulasso (Burkina Faso) were used. After shuffling, each sample was moistened to its optimum water content and then compacted to 90% and 95% of its optimum density. Behavior tests show that these soils deform very little when subjected to hydromechanical stresses. However, these deformations are swelling in nature for low mechanical stresses and when the stresses are high, they tend to collapse. When these soils are subjected to a vertical stress of 420 kPa, the primary consolidation time is of the order of one minute for NH<sub>2</sub> (a silty soil) and about ten minutes for NH<sub>3 </sub>(a silty-clayed soil).
基金This research was supported by the Knowledge Innovation Project of Chinese Academy of Sciences (KZCX2-SW-319).
文摘By testing soil organic matter （SOM） contents, soil water contents （SWC） within low suctions, and saturated infiltration rates of samples taken from east slope of Gongga Mountain of China, the enhancive effects of SOM contents on SWC within low suctions and saturated infiltration rates were quantified. The simulated functions might be applied on regional experience forest-hydrology model. The improving function of protecting forest floor and increasing SOM contents on forest ecosystem hydrological effects were also embodied.
基金supported by the China Geology Survey Work Program (No.1212011121277)
文摘In this paper, we proposed a new method that has been developed based on the surface soil moisture content(SSMC) to more efficiently calculate the groundwater evaporation in variably saturated flow modeling. In this method, the empirical formula to calculate evaporation was modified and the value of the formula varies from zero to one as a closed interval. In addition, the simulation code for calculating the groundwater evaporation based on the SSMC method was incorporated into the EOS9 module of Tough2, a variably saturated flow modeling code. Finally, two numerical tests and a case simulation were conducted to verify the feasibility and accuracy of the SSMC method. Simulation results indicate that the SSMC method is capable of appropriately simulating the characteristics of water flow in vadose zone and the amount of evaporation with the variable water table. And such results are in coincidence with the value calculated by the logistic function method, and fit well with the measured data globally rather than locally.
文摘针对合水油田庄XX区长8储层油井“微裂缝+高渗带”水淹现状,结合储层地质特点、动态开发特征等因素,开展堵水和原层补孔压裂技术相结合的储层改造试验。庄XX区长8平均油层厚度17.9 m,平均射孔段6.4 m,储层整体打开程度较低,为35.7%,这为“堵水和原层补孔压裂”提供了基础条件。2019—2021年,堵水压裂实践表明,在升压1~2 MPa、酚醛树脂体系、堵剂用量650 m 3条件下,效果较好,原层压裂改造参数为小排量1.6~1.8 m 3/min、低砂比20%、低砂量16~20 m 3,可达到控水增油目的。此方法充分发挥了油藏潜力,为同类油藏高含水井治理提供了借鉴与指导。
