6.2. SR 01-13-2003 - Laserfiche WebLink

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6.1 Drilling Rqulpment---Any dril- ling equipment that provides at the time of sampling a suitably clean open hole before insertion of the sampler and ensures that the penetration test ls performed on undisturbed soft shall be aceeptabls. The following pieces of equipment have proven to be suitable for advancing a borehole in some sub- su~fa~e conditions. 5.1.1 Drag, Chopping, and Fishtail Bits, less tb_~n 6.§ in. (162 mm) and gr~tter th~n 2.2 111. (56 mm) in diamet- er m~y be used In co~unotion with open-hole rotary drilling or casing- advanoemen~ drilling me,hods. To avoid disturbance of ~he underlying soil, ~t~m ~c~ge bl~ are not ~r- mit~d; o~ side dMchar~g bits a~e 5.1.2 Roller,one Bits, less th~ 6.5 ~. (162 mm) ~d ~ea~r than (56 mm) ~ di~e~r may be used co,unction with open-hole rotary dr~g or casing-advancement ~ill- lng methods ff the drill~g fluid dis- c~ge M deflec~d. 5.1.3 Hollow-Stem Continuous Fl~ht Augers, ~th or without a cen- ~r bit ~semb~, may be used the ~. ~e ~ide ~e~r of the hoHow-s~m a~ers sh~l be less than 6.5 ~. (162 mm) and ~ea~r th~ 2.2 ~. (56 mm). 5.1.4 Solid, Continuous Flight, Bucket ~d ~d A~ers, less ~ 6.5 ~. (162 mm) ~d ~ea~r th~ (56 mm) ~ d~me~r ~ ~ ~ ff ~e soft on ~e side of ~e ~r~ does not cave onto the sampler or sampling r~ d~ s~p~. 8.2 Sampling Hods--Flush-Joint s~el ~ r~ sh~ ~ used ~ ~ect the spllt-ba~el sampler to the ~lve- weight assembly. The sampl~g rod s~ ~ve a st~ness (moment of ~er- tis) equal ~ or ~eater than that of parallel wall 'A' rod (a steel rod w~ch has ~. (41.2 mm) ~d of 1R ~. (28.5 ~m). NOTE l--Recent research and oomp&rative testtng lndlc~e8 the type rod used. with stiffness l~n~ng from 'A' size rod to 'N' size rod, will usually have a negligible effect on the N-values to depth~ of &t lea~t 100 ft (30 m). §.3 Split-Barrel Sampler--The sam- pler shall be constructed with the menslons indicated in Fig. 2. The driv- ing shoe sb;~ll be of hardened steel and shall be replaced or repaired when it A$1'M ue$1gnauon: u lo~ becomes dented or distorted. The use of liners to produce a constant inside diarrleter of 1% in. (35 mm) iS permit- ted, but shall be noted on the penetra- tion record 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 &nd available test d~Lta 8~gest that N-values may increase between 10 to ~;0% when liners a~e used. §.4 Drive-Weight A~sembly: 5.4.1 Hammer and Anvil--The ham- mer shall weigh 140 ± 2 lb (63.5 ± 1. kg) and shall be a solid rigid metallic mass. The h~mmer shall strike the an- vil and make steel on steel contact when it is dropped. A'hammer fall. guide permitting a free fall shall be used. Hammers used with the cathead and rope method shall have an unim- peded overlfft capacity of at least 4 in. (100 mm). For safety reasons, the use of a h;cmmer assembly with an inter- nal anvil is encouraged. NOTE 3---It iS suggested that the h~mraer fall guide be permanently marked to enable the opera- tor or h-~spector to Judge the hammer ch'op 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. 5.5 Accessory Equipment--Acces- sories such as labels, sample contain- ers, data sheets, and groundwater lev- el measuring devlces shall be provlded in accordance wlth the requirements of the project and other ASTM start- 6. Dl~lltn_'l[ Procedure 6.1 The boring shall be advanced in- crementally to permit intermittent or continuous 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- rides a suitably clean and stable hole before Inse~tlon of the sampler and as- sures that the penetration test is per- formed on essentially undisturbed soft sh~ll be acceptable. Each of the follow- lng procedures have proven to be ac- ceptable for some subsurface condi- tions. The subsurface conditions anti- clpated should be considered when se- lecting the drilling method to be used. 6.2.1 Open-hole rotary drilling method. 6.2.2 Continuous flight hollow-stem auger method. 6.2.3 Wash boring method. 6.2.4 Continuous flight solid auger method. 6.3 Several-drilling 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-cohesive 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 permissibl'e 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 sltu 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 spllt-bar~el 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 Posltlon the hammer above and attach 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 bering and apply a seating blow. If excessive cuttings are encountered at the bottom of the boring, remove the sampler and sam- pllng ~ds from the bering and remove the cuttings. 7.1.4 Mark the drill rods in three successive 6-in. (0.1 §-m) increments