中国岩溶
中國巖溶
중국암용
CARSOLOGICA SINICA
2014年
1期
118-122
,共5页
刘伟%甘伏平%赵伟%陈玉玲
劉偉%甘伏平%趙偉%陳玉玲
류위%감복평%조위%진옥령
岩溶塌陷分区%高密度电法%低阻正交点%微动技术%特征频率
巖溶塌陷分區%高密度電法%低阻正交點%微動技術%特徵頻率
암용탑함분구%고밀도전법%저조정교점%미동기술%특정빈솔
karst collapsed area%high density resistivity method%low resistivity orthogonal point%microtremor sur-vey method%characteristic frequency
为了验证物探技术在岩溶塌陷调查中的应用效果,本文于广西来宾市吉利村开展了高密度电法和微动技术野外探测研究。结果表明:高密度对称四极电测深能直观地反映第四系覆盖层的厚度和低阻异常的深度,微动技术能定性地判定地下暗河和岩溶破碎带在地表的平面投影,将两种方法相结合能更加准确地圈出塌陷,以及引起塌陷的溶洞、地下河、断层破碎带及软土分布范围。地下暗河或岩溶破碎带在高密度联合剖面法上反映为低阻正交点异常,极距为45 m时正交点附近电阻率值约为250Ω·m;在微动 H/V比值谱上反映为 H/V极大值异常,极大值特征频率在2~6 Hz之间。依据2测线上的高密度电法和微动异常显示,圈出了两个易塌陷区,经对其中的一异常进行钻探验证,异常区覆盖层下42 m 厚的灰岩地层中钻遇溶洞8个,其中最大的高达5.7 m。
為瞭驗證物探技術在巖溶塌陷調查中的應用效果,本文于廣西來賓市吉利村開展瞭高密度電法和微動技術野外探測研究。結果錶明:高密度對稱四極電測深能直觀地反映第四繫覆蓋層的厚度和低阻異常的深度,微動技術能定性地判定地下暗河和巖溶破碎帶在地錶的平麵投影,將兩種方法相結閤能更加準確地圈齣塌陷,以及引起塌陷的溶洞、地下河、斷層破碎帶及軟土分佈範圍。地下暗河或巖溶破碎帶在高密度聯閤剖麵法上反映為低阻正交點異常,極距為45 m時正交點附近電阻率值約為250Ω·m;在微動 H/V比值譜上反映為 H/V極大值異常,極大值特徵頻率在2~6 Hz之間。依據2測線上的高密度電法和微動異常顯示,圈齣瞭兩箇易塌陷區,經對其中的一異常進行鑽探驗證,異常區覆蓋層下42 m 厚的灰巖地層中鑽遇溶洞8箇,其中最大的高達5.7 m。
위료험증물탐기술재암용탑함조사중적응용효과,본문우엄서래빈시길리촌개전료고밀도전법화미동기술야외탐측연구。결과표명:고밀도대칭사겁전측심능직관지반영제사계복개층적후도화저조이상적심도,미동기술능정성지판정지하암하화암용파쇄대재지표적평면투영,장량충방법상결합능경가준학지권출탑함,이급인기탑함적용동、지하하、단층파쇄대급연토분포범위。지하암하혹암용파쇄대재고밀도연합부면법상반영위저조정교점이상,겁거위45 m시정교점부근전조솔치약위250Ω·m;재미동 H/V비치보상반영위 H/V겁대치이상,겁대치특정빈솔재2~6 Hz지간。의거2측선상적고밀도전법화미동이상현시,권출료량개역탑함구,경대기중적일이상진행찬탐험증,이상구복개층하42 m 후적회암지층중찬우용동8개,기중최대적고체5.7 m。
In order to verify the applicability of geophysical prospecting technology to the investigation of karst col-lapse,the field research was carried out employing high density resistivity and micro technology methods in Jili vil-lage,Laibin City,Guangxi.It showed that the high density symmetric quadrupole sounding method intuitively re-flected the thickness of the Quaternary overburden layer and the depth of the low resistivity section underground, while micro technology qualitatively analyzed the surface proj ection of the underground river and karst fracture zone. This would be more accurate in the case of circling collapse and unfavorable geologic bodies which caused collapse, such as caves,underground rivers,fault fracture zones and soft soil by combing two methods.It also showed that a low resistivity orthogonal point appeared in the high density profiling curve and its value was about 250Ω·m when the polar distance was 45 m while a great value anomaly appeared on the H/V spectrum and the maximum character-istic frequency was in the range of 2-6 Hz above the underground river or karst fracture zone.On the basis of anom-alies in the high density resistivity method and micro method of the line 2,the two sections circled were easy to col-lapse and one selected to be verified by drilling.Drilling revealed eight caves in limestone covered by a 42 m thick Quaternary overburden,of which the largest cave was up to 5 .7 m in height.