ASTM D6035/D6035M-13由美国材料与试验协会 US-ASTM 发布于 2013。
ASTM D6035/D6035M-13 在中国标准分类中归属于: P22 地基、基础工程。
4.1 This test method identifies the changes in hydraulic conductivity as a result of freeze-thaw on natural soils only.
4.2 It is the user''s responsibility when using this test method to determine the appropriate water content of the laboratory-compacted specimens (that is, dry, wet, or at optimum water content) (Note 2).
Note 2—It is common practice to construct clay liners and covers at optimum or greater than optimum water content. Specimens compacted dry of optimum water content typically do not contain larger pore sizes as a result of freeze-thaw because the effects of freeze-thaw are minimized by the lack of water in the sample. Therefore, the effect of freeze-thaw on the hydraulic conductivity is minimal, or the hydraulic conductivity may increase slightly.34.3 The requestor must provide information regarding the effective stresses to be applied during testing, especially for determining the final hydraulic conductivity. Using high effective stresses (that is, 35 kPa [5 psi] as allowed by Test Method D5084) can decrease an already increased hydraulic conductivity resulting in lower final hydraulic conductivity values. The long-term effect of freeze-thaw on the hydraulic conductivity of compacted soils is unknown. The increased hydraulic conductivity caused by freeze-thaw may be temporary. For example, the overburden pressure imparted by the waste placed on a soil liner in a landfill after being subjected to freeze-thaw may reduce the size of the cracks and pores that cause the increase in hydraulic conductivity. It is not known if the pressure would overcome the macroscopically increased hydraulic conductivity sufficiently to return the soil to its original hydraulic conductivity (prior to freeze-thaw). For cases such as landfill covers, where the overburden pressure is low, the increase in hydraulic conductivity due to freeze-thaw will likely be permanent. Thus, the requestor must take the application of the test method into account when establishing the effective stress.
4.4 The specimen shall be frozen to8201;−15°C [5°F] unless the requestor specifically dictates otherwise. It has been documented in the literature that the initial (that is, 0 to8201;−15°C [32°F to 5°F]) freezing condition causes the most significant effects3 in hydraulic conductivity. Freezing rate and ultimate temperature should mimic the field conditions. It has been shown that superfreezing (that is, freezing the specimen at very cold temperatures and very short time periods) produces erroneous results.
4.5 The thawed specimen temperature and thaw rate shall mimic field conditions. Thawing specimens in an oven (that is, overheating) will produce erroneous results.
4.6 Literature relating to this subject indicates that the effects of freeze-thaw usually occur by Cycle 10, thus it is recommended that at least 10 freeze-thaw cycles shall be performed to ensure that the full effects of freeze-thaw are measured. If the hydraulic conductivity values are still increasing after 10 freeze-thaw cycles, the test method shall be continued (that is, more freeze-thaw cycles shall be performed).
Note 3—The quality of the result produced by this standard is dependent on the competen......它采用两节9伏电池提供个低能电场,当它以屋面上移动时,其底部的柔性电随时监测屋面的导电性能。...
也可根据下式求渗透系数(k):1“Lu”=10-125px/s二、仪器与主要设备钻孔压水试验设备主要由压水系统,量测系统和止水系统三部分组成。压水系统包括水箱、水位计和水泵;量测系统包括压力表和流量计;止水系统包括止水栓塞或气泵等。...
也可根据下式求渗透系数(k):1“Lu”=10-5cm/s二、仪器与主要设备钻孔压水试验设备主要由压水系统,量测系统和止水系统三部分组成。压水系统包括水箱、水位计和水泵;量测系统包括压力表和流量计;止水系统包括止水栓塞或气泵等。...
压水系统包括水箱、水位计和水泵;量测系统包括压力表和流量计;止水系统包括止水栓塞或气泵等。在钻孔中,目标测试地层内用封堵器进行分隔(图中黑色部分),然后向该分隔区段施加 10 巴(150 psi)的恒定压力,通过测试该区段中水的体积变化来计算该地层的渗透率。水的体积变化可以从地面上的水位计中读出。时间通过秒表计时。钻孔压水试验的用途:确定岩体的渗透特性。计算岩体相对透水性和了解裂隙发育程度。...
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