为研究高土石坝坝体内土体单元在复杂应力状态下的渗透性能,在中型三轴仪上对同一土料场3种不同级配土料进行三轴渗透试验。试验围压分为5级(100 k Pa、400 k Pa、800 k Pa、1 200k Pa和2 000 k Pa),每级围压下分4种应力水平(0、0.2、0....为研究高土石坝坝体内土体单元在复杂应力状态下的渗透性能,在中型三轴仪上对同一土料场3种不同级配土料进行三轴渗透试验。试验围压分为5级(100 k Pa、400 k Pa、800 k Pa、1 200k Pa和2 000 k Pa),每级围压下分4种应力水平(0、0.2、0.4和0.8),当试样在初始应力状态下变形基本稳定后,采用常水头法测试试样的渗透系数。试验结果表明:级配是影响渗透系数的重要因素,相同应力条件下土料粉粒和黏粒含量越高,渗透系数越小;随围压和应力水平的提高,土料的渗透系数逐渐降低;粉粒和黏粒含量越低、大颗粒含量越高,围压对土料渗透系数的影响越显著;对于不同级配相同密实度试样,应力水平对渗透系数的影响程度基本一致。在分析渗透系数随围压和应力水平变化规律的基础上,建立了能描述复杂应力状态条件下土体渗透系数的经验公式。展开更多
In Japan, floods occur frequently in urban areas because non-infiltrating areas are seeing increased urbanization. To prevent floods, urban basins must improve the infiltration capacity and water retention of the whol...In Japan, floods occur frequently in urban areas because non-infiltrating areas are seeing increased urbanization. To prevent floods, urban basins must improve the infiltration capacity and water retention of the whole basin. There are several basic technologies for river basin management, such as infiltration trenches or rainwater storage. However, a method of soil amendment that prevents flood disasters has not been established. This study aims to evaluate the infiltration capacity of soil amendments using bamboo charcoal and humus. A constant-head infiltration test and rainfall simulation were conducted to evaluate the properties of the soil amendments. The constant-head infiltration test＇s results showed that soils mixed with 30% humus had the greatest potential for influencing initial and final infiltration rates, and the more the mixing rates of bamboo charcoal and humus were increased, the higher the water retention capacity. The results of the rainfall simulation showed that soils mixed with 30% humus had the highest final infiltration rates and lowest multiplication spillage. To reduce the runoff volume using soil amendment technology, it is important to delay overland flow, and the hydraulic properties of the soils mixed with bamboo charcoal and humus were as effective as those of granite soils.展开更多
为了探究测定时间对定水头法土壤饱和导水率(Saturated soil hydraulic conductivity,Ks)测定结果的影响,采用室内模拟试验,以关中塿土为研究对象,测定原状土(1.5 g cm-3)及不同容重(1.2、1.3、1.4、1.5、1.6 g cm-3)扰动土长时间序列下...为了探究测定时间对定水头法土壤饱和导水率(Saturated soil hydraulic conductivity,Ks)测定结果的影响,采用室内模拟试验,以关中塿土为研究对象,测定原状土(1.5 g cm-3)及不同容重(1.2、1.3、1.4、1.5、1.6 g cm-3)扰动土长时间序列下(45 d)的饱和导水率及出流液电导率,并在实验结束后将土样分层用吸管法测定颗粒组成。结果表明:饱和导水率测定值随时间先迅速降低达到一个拐点(近稳定点)后缓慢降低至最终稳定,对于原状塿土,近稳定点(1.33 d)Ks测定值0.0762 cm h-1与终稳定点(4.42 d)Ks值0.0640 cm h-1差异不显著(P>0.05),初步建议测定时间为1.5 d。原状土比同容重的扰动土先达到稳定且稳定时的Ks值更大,随着土壤容重增加,Ks越快稳定(分别4.92、4.42、2.92、2.5、1.5 d),且稳定时Ks值越小。不同时刻出流液的电导率与饱和导水率极显著相关(P<0.01),试验后粉粒含量随土样深度有所上升,说明土粒的膨胀与迁移对Ks测定的稳定时间均有影响。展开更多
文摘为研究高土石坝坝体内土体单元在复杂应力状态下的渗透性能,在中型三轴仪上对同一土料场3种不同级配土料进行三轴渗透试验。试验围压分为5级(100 k Pa、400 k Pa、800 k Pa、1 200k Pa和2 000 k Pa),每级围压下分4种应力水平(0、0.2、0.4和0.8),当试样在初始应力状态下变形基本稳定后,采用常水头法测试试样的渗透系数。试验结果表明:级配是影响渗透系数的重要因素,相同应力条件下土料粉粒和黏粒含量越高,渗透系数越小;随围压和应力水平的提高,土料的渗透系数逐渐降低;粉粒和黏粒含量越低、大颗粒含量越高,围压对土料渗透系数的影响越显著;对于不同级配相同密实度试样,应力水平对渗透系数的影响程度基本一致。在分析渗透系数随围压和应力水平变化规律的基础上,建立了能描述复杂应力状态条件下土体渗透系数的经验公式。
文摘In Japan, floods occur frequently in urban areas because non-infiltrating areas are seeing increased urbanization. To prevent floods, urban basins must improve the infiltration capacity and water retention of the whole basin. There are several basic technologies for river basin management, such as infiltration trenches or rainwater storage. However, a method of soil amendment that prevents flood disasters has not been established. This study aims to evaluate the infiltration capacity of soil amendments using bamboo charcoal and humus. A constant-head infiltration test and rainfall simulation were conducted to evaluate the properties of the soil amendments. The constant-head infiltration test＇s results showed that soils mixed with 30% humus had the greatest potential for influencing initial and final infiltration rates, and the more the mixing rates of bamboo charcoal and humus were increased, the higher the water retention capacity. The results of the rainfall simulation showed that soils mixed with 30% humus had the highest final infiltration rates and lowest multiplication spillage. To reduce the runoff volume using soil amendment technology, it is important to delay overland flow, and the hydraulic properties of the soils mixed with bamboo charcoal and humus were as effective as those of granite soils.
文摘为了探究测定时间对定水头法土壤饱和导水率(Saturated soil hydraulic conductivity,Ks)测定结果的影响,采用室内模拟试验,以关中塿土为研究对象,测定原状土(1.5 g cm-3)及不同容重(1.2、1.3、1.4、1.5、1.6 g cm-3)扰动土长时间序列下(45 d)的饱和导水率及出流液电导率,并在实验结束后将土样分层用吸管法测定颗粒组成。结果表明:饱和导水率测定值随时间先迅速降低达到一个拐点(近稳定点)后缓慢降低至最终稳定,对于原状塿土,近稳定点(1.33 d)Ks测定值0.0762 cm h-1与终稳定点(4.42 d)Ks值0.0640 cm h-1差异不显著(P>0.05),初步建议测定时间为1.5 d。原状土比同容重的扰动土先达到稳定且稳定时的Ks值更大,随着土壤容重增加,Ks越快稳定(分别4.92、4.42、2.92、2.5、1.5 d),且稳定时Ks值越小。不同时刻出流液的电导率与饱和导水率极显著相关(P<0.01),试验后粉粒含量随土样深度有所上升,说明土粒的膨胀与迁移对Ks测定的稳定时间均有影响。
