Home > Archive>Volume 51, Issue 3, 2024 >27-36. DOI:10.12143/j.ztgc.2024.03.004
PDF HTML XML Export Cite reminder
Experimental study on microcosmic characteristics of organic polluted formations encountered by direct push drilling
CSTR:
[cstr]
Author:
Affiliation:

1.Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring;(Central South University), Ministry of Education, Changsha Hunan 410083, China;2.Key Laboratory of Non-Ferrous Resources and Geological Hazard Detection, Changsha Hunan 410083, China;3.School of Geosciences and Info-Physics, Central South University, Changsha Hunan 410083, China;4.Changsha General Survey of Natural Resources Center, Ningxiang Hunan 410600

Clc Number:

P634;X83

  • Article
    • | |
  • Metrics
    • |
  • Reference
    • |
  • Related
    • |
  • Cited by
    • | |
  • Comments
    Abstract:

    Direct push drilling technology has the advantages of no flushing medium， fast speed， small disturbance， etc.， but it is susceptible to the interference of factors such as large differences in the engineering properties of the soil at the site of organic contamination， resulting in tilting of the borehole and other phenomena. Organic pollutants will change the microstructure of the soil， resulting in changes in soil engineering properties， which in turn reduces the accuracy of direct drilling sampling points. Typical organic pollutants toluene and perchloroethylene were selected， and soil samples with different pollutant concentrations （toluene： 75， 120 and 672 mg/kg； perchloroethylene： 11， 53 and 183 mg/kg） were prepared to simulate the drilling encountered with the organically contaminated stratum. XRD， SEM， contact angle and nitrogen adsorption and desorption tests were carried out to investigate the changing rules of microstructure of the soil samples under the influence of different organic pollutant concentrations.The results of the SEM image analysis and nitrogen adsorption and desorption tests showed that： toluene and perchloroethylene encapsulated and chemically damaged soil samples， resulting in the agglomeration of soil particles， the reduction of the specific surface area， the obvious increase in the number of small pores， and the decrease in the pore volume of soil； the content of clay particles was 30.28% at the highest level. The highest clay content of 30.28% in soil sample 2# after 672mg/kg toluene and 183mg/kg tetrachloroethylene contamination， the specific surface area decreased by 30.70% and 33.40%， respectively， and the Pearson''s correlation coefficient of r=0.382 indicates that there is a certain positive correlation between the content of clay particles and the rate of reduction of the specific surface area. Meanwhile， due to the wrapping effect of non-polar molecules toluene and perchloroethylene on the soil particles， the hydrophilic groups of the soil samples were isolated， resulting in the deterioration of the hydrophilicity of the soil samples and the increase of the contact angle. This study suggests that organic pollutants can lead to changes in the microscopic characteristics of the soil， which ultimately leads to an increase in the non-homogeneity of the organically contaminated strata， which in turn can have an impact on the direct push drilling trajectory.

    Reference
    Related
    Cited by
Get Citation

Copy
Share
Article Metrics
  • Abstract:
  • PDF:
  • HTML:
  • Cited by:
History
  • Received:March 22,2024
  • Revised:May 01,2024
  • Adopted:May 06,2024
  • Online: May 30,2024
  • Published: May 10,2024
Article QR Code
Today's visits： Total visits：   津ICP备19010518号-1  

津公网安备12011002024030号
Address：No.77 Jinguang District, Langfang City, Hebei Province Post Code：065000 Phone：0316-2096324
URL：http://www.tkgc.net/ E-mail：tkgc@mail.cgs.gov.cn
Drilling Engineering ® 2025 All Rights ReservedSupported by:Beijing E-Tiller Technology Development Co., Ltd.