07/15/2004 Env Bd Packet - Laserfiche WebLink

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S. ADDirstas * Drilling Equipment —Any dril- 1 quipment that provides at the tik..,, of sampling a suitably olean open t hole before insertion of the Sampler and ensures that the penetration teat is performed on undisturbed Boil shall be acceptable. The following pieces of t }equipment have proven to be suitable • ?for advancing a borehole in some sub- s surfaoe conditions. t I 8.1.1 Drag, Chopping, and Fishtail Bite, less than 6.8 in. (182 mm) and greater than 2 2 in. (86 mm) in diamet- ier may be lased in conjunction with open -hole rotary drilling or casing - 'iadvanoement drilling methods. To • avoid disturbance of. .the underlying ?soil, bottom discharge bite are not per - mitted; only side discharging bits are ipermitted. 5.1.2 Roller-Cone Bits, less than 8.5 . in. (162 mm) and greater than 2.2 in. (88 mm) in diameter may be need in conjunction with open -hole rotary ?drilling or casing- advancement drill - ing methods if the drilling fluid die- :; e is deflected. .3 Hollow-Stem ' ? em Continuous FLgnt Augers, with or without a oen- ter bit assembly, may be used to drill the boring: -The- inside diameter of the hollow -stem augers shall be leas than 8.8 in. (182 mm) and greater than 2.2 in. (88 mm). 8.1.4 Solid, Continuous Flight, Buoket and Hand Augers, less than 8.8 in. (162 mm) and greater than 2.2 in. (86 mars) in diameter may be used if the eon on the side of the boring does not Dave onto the sampler or sampling rods during sampling. 8.2 Sampling Rods—Flush-joint steel drill rods shall be used to connect the split - barrel sampler to the drive- , weight .assembly. The sampling rod shall have a stiffness (moment of finer- tia) equal to or greater than that of parallel wall "A" rod (a steel rod which `has .ii oiitMde diameter of 1% in. (41.2 mm) and an inside diameter of 1% in. (28.5 mm). NOTE 1— Repent research and oomparative - lipsindicates the type rod used, with stiffness from 'A" else rod to "N" size rod, will .ly have a Negligible effeot on the N- values to depths of at least 100 ft (30 m). 8.3 Split- Barrel Sampler —The sam- pler shall be constructed with the di- mensions indicated in Fig. 2. The driv- ing shoe shall be of hardened steel and shall be replaced or repaired when it ASTM Designation: D 1586 becomes dented or distorted. The use of liners to produoe a constant inside diameter of 1% in. (38 mm) Is permit- ted, but shall be noted on the penetra- tion reoord if used. The use of a sample retainer basket is permitted, and should also be noted on the penetra- tion record if used. NOTE 2 —Both theory and available test data suggest that N- values may inoresse between 10 to 3096 when liners are used. 5.4 Drive - Weight Assembly: 5.4.1 Hammer and Anvil —The ham- mer shall weigh 140 t 2 lb (83.8 t 1. kg) and shall be a solid rigid metallic mass. The hammer shall strike the an- vil and make steel on steel contact when it is dropped. -'4%.-hammer fall. guide permitting a free fall shall be used. Hammers used with the cathead and rope method shall have- an•unim- peded overlift capacity of at least 4 in. (100 mm). For safety reasons, the use of a• hammer assembly with an inter- nal anvil is encouraged. NOTE 3—It le suggested that the hammer fall guide be permanently marked to enable the opera- tor or inspector to Judge the hammer drop height. 5.4.2 Hammer Drop System —Rope- cathead, trip, semi- automatic, or auto- matic hammer drop systems may be used, providing the lifting apparatus will not cause penetration of the sampler while re- engaging and lifting the hammer. 8.8 Accessory Equipment—Acoes- sories such as labels, sample contain- ers, data sheets, and groundwater lev- el measuring devices shall be provided -in accordance with the requirements of the project and other ASTM stan- dards. 6. Drilling Procedure 6.1 The boring shall be advanced in- crementally to permit intermittent or ' oontinuous: sampling. `Test intervals and locations are normally stipulated by the project engineer or geologist. Typically, the intervals selected are 5 ft (1.5 m) or less in homogeneous strata with test and sampling locations at every change of strata. 6.2 Any drilling procedure that pro- vides a suitably Olean and stable hole before insertion of the sampler and as- sures that the penetration test is per- formed on essentially undisturbed soil shall be acceptable. Each of the follow- big prooedures have proven to be ac- ceptable for some subsurface oondi- tions. The subsurface conditions anti- cipated should be considered when se- lecting the drilling method to be used. 8.2.1 Open -hole rotary drilling method. 6.2.2 Continuous flight hollow -stem auger method. 8.2.3 Wash boring method. 8.2.4 Continuous flight solid auger method. 6.3 Several•drllling methods produce unacceptable borings. The process of jetting. through an open tube .sampler and then sampling when the desired depth is reached shall not be permit- ted. The continuous flight solid auger •• ••. method; shall not be used for advanc- ing the. boring below a water table or below. the upper confining bed of a confined non- oohesive stratum that is under artesian pressure. Casing may not be advanced below the sampling elevation prior to sampling. Advancing a boring with bottom discharge bits is not permissible. It is not permissible to advance the boring for subsequent insertion of the sampler solely by means of previous sampling with the SPT sampler. 6.4 The drilling fluid level within the boring or hollow -stem augers shall be maintained at or above the in situ groundwater level at all times during drilling, removal of drill rods, and sampling. 7. Sampling and Testing Procedure 7.1 After the boring has been ad- vanced to the desired sampling eleva- . tion and excessive cuttings have been removed, •prepare for the test with the following :sequence of operations. 7.1.1 Attach the -split-barrel sampler to the sampling rods and lower into borehole. Do : not allow the sampler to drop onto the soil to be sampled. 7.1.2 Position the hammer above and attaoh the anvil to the top of the -sampling rods..-This. may, be done, be- fore the .sampling rods and sampler are lowered into the borehole. 7.1.3 Rest the dead weight of the sampler, rods, anvil, and drive weight on the bottom of the boring and apply a seating blow. If excessive cuttings are encountered at the bottom of the boring, remove the sampler and sam- pling rode from the boring and remove the cuttings. 7.1.4 Mark the drill rods in three successive 6 -in. (0.15-m) inorements