BLASTING VIBRATIONS AND .THEIR EFFECTS ON STRUCTURES

1 Bulletin 656. BLASTING VIBRATIONS . AND . their EFFECTS ON STRUCTURES . By Harry R. Nicholls, Charles F. Johnson, and Wilbur I. Duvall US Department of Interior Office of Surface Mining Reclamation and Enforcement Kenneth K. Eltschlager Mining/Explosives Engineer 3 Parkway Center Pittsburgh, PA 15220. Phone Fax UNITED STATES DEPARTMENT OF THE INTERIOR. BUREAU OF MINES. CONTENTS. Page Page List of Symboll - - - 'ri law - - - - - - - 52. Abstract - I of charge weight for Chapter introduction I instantaneous blasts 54. _ I of delay interval and meeting - - - - - - - - - 2 number of holea - - - - - - - - U-History - - - - - - - - - - - - - - - 2 of milliaecond.

2 U-General approach to the problem -- -- 5 delayed blaata with instantaneous - -- -- ---~--- ---- 4 blasts ~--- - - --------- 40. Chapter - - ---- 5 as a scaling factor ------ -- it --- - -- - - - -- 5 4.!.1-Experimental procedure - - - - - it ;-~e dynamic response of a 4.!.2-Data analysis -- - -- -- - - 41. selSIIllc transducer - --- - - -- 5 of method of initiation - - - -- 50. transducer - - - - 6 procedure -- - - 52. transducer - -- -- 6 analysis - - - - -----. 55. transducer ---- 7 of geolog-_', including direction of typical -- - 7 of propagation an~ overburden - ----- stability ----- -- - - 8 and direction.

3 Calibration - --- - 10 of rock type on vibration used by the Ieveii --- -- -- - ---- 55. Bureau of Minea - - - -- - - --- 10 !-0verburden - - - --- -- 59. - - - - - - -- 12 of Fourier analysis Chapter vibration Ieveii for residential techniques to vibration data - - - --- 59. STRUCTURES --- -- ------ - - -- - - - 15 and acceleration - - - - - - - - - -- 15 from particle velocities - - - - - 60. study of published data on of instantaneous ground VIBRATIONS and damage - - - - -- 15 and delay-type BLASTING through 5~.1-Investigationa by the Fourier techniques - - - - - - - 60. ) Bureau of Mines - -- - - 15 -- -- - --- - - 65.

4 By Langefon, Chapter and propagation of air Kihlstrom, and Westerberg - - 14 VIBRATIONS from BLASTING - ---- - - --- 64. by Edwards and - -- - ---- - - 64. Northwood - - - - - - - 14 published data - - - - - - - 64. of damage data - 18 5.!-Bureau of Mines data -- - -- - -- 67. from other inveatigaton - - 19 - - -- - - - --- - -- 68. Bureau of Mines data - - - 20 Chapter safe air and ground 55-Building VIBRATIONS from normal vibration Ieveii for BLASTING - - - - - - - - 69. activities - - - - - ---- 21 - - ---- - - ----- 69. of particle motion vibration limits with calculations - - - ---- - 21 instrumentation - --- - - ---- 69.

5 Safe ground vibration vibration limits without Ieveii - - - - - - - - - -- 22 instrumentation - - - - - - - - - -- 70. data on air VIBRATIONS and of scaled distance as a BLASTING damage - - -- - --- ---- ----- 25 control - - - - - - -- -- -- 70. safe air blast pressure air blaat limits - --- - 72. levels - --- - - - - - - --- 27 Chapter and concluaiona - -- - 75. response and ita effect on - -- ---- - --- -- - 'IS. safe vibration Ieveii - - - - - - - - 27 - - - - 75. -- - - - ---- 29 Adnowledgmenta - - - --- --- - - 75. Chapter . and propagation of ground Explanation of Appendices - - - --- 76.

6 VIBRATIONS from blastiDJ - -- - - - - -- !10 Appendix views of test sites - - - - - 76. - - - - - -- 51 Appendix and loading data -- -- 86. blasts venus Appendix velocity and frequency instantaneous blasts .. 52 data - - - - - 92. procedure - - -- 52 Appendix description ------ 104. ILLUSTRATIONS. Fig. Mau-spring-dashpot model of a seismic transd~cer - - - - - - -- ---~------ Theoretical response curves for a typical displacement or velocity transducer - - - - - - 2.!. Theoretical response curves for a typical acceleration transducer - - - - - - - .. Fis. Page Horizontal location of centrr of gravity of a lamina.

7 - -- - - -- -- 9. Vertical location of center of gravity of a aeismograph ..- - - - 9. Frequency responae curve of linear amplifier- ------ ---- - II. Frequency responae curve of velocity gage ..- - - - - - - - - - - - - - - II. Displacement versus frequency for obaerved damagle, Bureau of Minaa ..- - - 15. Displacement versus frequency for ohaerved damage, and others -- - - -- --- - -- 16. S.!J. Displacement versus frequency for obaerved damage, Edwards and Northwood - - - - - - - - 17. Displacement versus frequency, combined data with ecommended safe BLASTING criterion ------ -- -- 18.

8 U. Comparison of displacements from integration and simple harmonic motion calculations - --- - - 2S. Comparison of particle velocities as recorded and from displacements - - --- --- --- - - 2-i Particle velocity versus frequency with recommended safe BLASTING aiterion --- - 25. Particle velocity versus frequency for no damage _ _. 26. Subjective responae of the human body to vibratory JI >tion (after Goldman) -- - ------ - - 27. Complaint history, Salmon Nuclear Event, with superposed subjective response--- - 28. vibration records for 1-hole blast .. --- - ------ - - -- S2.

9 vibration records for 7-hole instantaneous blast ..- - - - - - - - - - SS. 4.!1. vibration records for 7-hole, blast .. - - - - - - - - - - - - - S-i vibration records for 7-hole, !4-millisecond-delayed blast .. ----- --- - ---- !15. Particle velocity versus distance .for 1 and blasts ..- - - - - - - - - - - - - - - - S6. Particle velocity versus distance for 7 and 15-hole blasts .. !17. Particle velocity versus distance for a l hole and 2 m ultiple-row blasts .. S8. Comparison of effect of charge weight on level of vibration from instantaneous and millisecood-delayed blasts.

10 S9. Peak particle velocity versus distance, radial component .. 4S. Peak particle velocity versus distance, vertical component .. -- ------- - - 4-i Peak particle velocity versus distance, transverse component ..- - - - - - - - 45. Particle velocity intercepts versu~ charge weight per delay, radial component-- - -- - - ----- - - - 46. Particle velocity intercepts versu5 charge weight per delay, vertical component ..- - - - - - - 48. Particle velocity intercepts versus charge weight per delay, transverse component .. 48. Peak particle velocity versus scaled distance, radial component.