Spoon sampler

The simplest adequate sampling device should be used. Where the contaminant Is believed to be on the surface, a soil punch or trowel may be used. If the contaminant Is soluble or Is expected to be located more than a meter below the surface, a truck mounted core sampler such as a split spoon sampler should be used. 

A spoon sampler consists of one or more pipes, arranged like the spokes of a wheel. Openings located at the tips collect the sample as the device is rotated through coal on a moving belt. This machine can be designed to collect very small primary increments, but the spoon pipes may overflow during increment collection and the sample may be of questionable reliability. 

Equipment blanks enable us to assess the collected sample representativeness. The purpose of collecting equipment blanks is to detect the presence of contamination from the sampling equipment itself or any cross-contamination with previously collected samples. For example, metal liners for core barrel or split spoon samplers are not always precleaned by the manufacturer or distributor. They must be cleaned in the field prior to sampling to eliminate the potential for sample contamination. 

To sample with airtight coring devices, we must have access to exposed soil, which may be the ground surface, the bottom and sidewalls of an excavation, the stockpile face or side, or soil in the excavator bucket. We may also apply this technique for sampling of subsurface soil brought to the ground level in a split spoon sampler. 

To sample subsurface soil with a split-spoon sampler, we follow these steps ... 

Drill to the desired depth and retrieve the auger. Attach the split spoon sampler with 3 liners inside to the sampling rod and insert into the boring. Drive the split spoon sampler further down the borehole according to ASTM Method D1586. 

Retrieve the split spoon sampler from the borehole and open it. 

Figure 1.1 Split spoon sampler. (Reprinted with permission from The Annual Book of ASTM Standards, copyright ASTM, 100 Bar Harbour Drive, West Conshohocken, PA, 19428.)...

Core samples of the glacial drift were retrieved during the installation of wells and piezometers in the study area. In order to avoid contamination of the core samples, a hollow-stem auger and split-spoon sampler were used. 

Standard Penetration Test (SPT) An indication of the density or consistency of soils given by counting the number of blows required to drive a 2 inch OD split spoon sampler 12 inches using a 140 pound hammer falling 30 inches. The sampler is driven in three 6 inch increments. The sum of the blows required for the last two increments is referred to as the N value, blow count, or Standard Penetration Resistance. 

In the early years of the SPT, equipment and procedural differences made it impossible to compare test results. However, the procedures described in ASTM D1583 and recommendations summarized by Seed et al. (1985) have largely standardized the test, hence its name. The test requires the 140 lb hammer to be raised 30 in. and dropped, driving the sampler into the soil. This process is repeated until the sampler has penetrated 18 in. into the soil at the bottom of the borehole. The number of blows required to advance the sampler each of three 6 in. increments are recorded. After lifting the split-spoon sampler from the borehole and removing the soil... 

Early SPT hammers transferred approximately 60 % of the theoretical impact energy to the split-spoon sampler. Therefore, many correlations between SPT-Af and soil properties are based on this 60 % efficiency. Other factors affecting N include borehole diameter, type of sampler, and rod length. The blow count standardized to 60 % efficiency and corrected for the other factors is designated as N q. Skempton (1986) used Eq. 1 to convert N to N o-... 

Dynamic Soil Properties In Situ Characterization Using Penetration Tests, Fig. 4 Opened split-spoon sampler revealing clayey soil being tested with a pocket penetrometer... 

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