(e) Technique for sampling. 



(f) Method of storing and documenting the sample. 



Beaches typically show more variation across the profile than along the 

 shore, so sampling to determine variation in the littoral zone should usually 

 be made along a line perpendicular to the shoreline. 



For reconnaissance sampling, a sample from both the wetted beach face and 

 from the dunes is recommended. More extensive samples can be obtained at 

 constant spacings across the beach or at different locations on the beach 

 profile. Spacings betveen sampling lines are determined by the variation 

 visible along the beach or by statistical techniques. 



Many beaches have subsurface layers of peat or other fine material. If 

 this material will affect the engineering problem, vertical holes or borings 

 should be made to obtain samples at depth. 



Sample volume should be adequate for analysis: 50 grams is required for 

 sieve analysis; for settling tube analysis, smaller quantities will suffice, 

 but at least 50 grams is needed if other studies are required later. A 

 quarter of a cup is more than adequate for most uses. 



Sand often occurs in fine laminas on beaches. However, for engineering 

 applications it is rarely necessary to sample individual laminas of sand. It 

 is easier and more representative to take an equidimensional sample that cuts 

 across many laminas. Experience at CERC suggests that any method of obtaining 

 an adequate volume of sample covering a few centimeters in depth usually gives 

 satisfactory results. Cores should be taken where pile foundations are 

 planned . 



The sample is only as good as the information identifying it. The 

 following minimum information should be recorded at the time of sampling: 

 locality, date and time, position on beach, remarks, and initials of col- 

 lector. This information must stay with the sample; this is best ensured by 

 fixing it to the sample container or placing it inside the container. Unless 

 precautions are taken, the sample label may deteriorate due to moisture, 

 abrasion, or other causes. Using ballpoint ink on plastic strip (plastic 

 orange flagging commonly used by surveyors) will produce a label which can be 

 stored in the bag with the wet sample without deterioriating or the 

 information vashing or wearing off. Some information may be preprinted by 

 rubber stamp on the plastic strip using indelible laundry ink. 



7 . Size Analyses . 



Three common methods of analyzing beach sediment for size are visual 

 comparison with a standard, sieve analysis, and settling tube analysis. 



The mean size of a sand sample can be estimated qualitatively by visually 

 comparing the sample with sands of known sizes. Standards can be easily 

 prepared by sieving selected diameters, or by selecting samples whose sizes 

 are already known. The standards may be kept in labeled transparent vials or 

 glued on cards. If glued, care is necessary to ensure that the particles 

 retained by the glue are truly representative of the standard. 



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