Research And Application Of Multi-section Control Grouting Steel Tube Support Reinforcement Technology

In view of slope disaster problem,the urgent need for rapid,safe and efficient disposal should be considered.The current conventional technologies such as anti-slide piles and anchor cables are difficult to meet the technical requirements of emergency rescue;in the conventional technology of soil edge(slip)slope treatment,Anchor(rod)cable anchoring force is limited;There are some unfavorable factors such as construction safety problem and long construction cycle for anti-slide piles and other.Based on the above,research on the rapid,safe,economic and reasonable new prevention technology has become a hot issue in the field of slope disaster,which has broad application prospects.In order to study the new technology of edge(slip)slope retaining reinforcement,this paper is devoted to the research and application of multi-section control grouting steel tube technology.Through the model test,mechanical analysis,numerical simulation,physical engineering verification and other means to deeply analyze the structural form,applicable conditions,design calculation method,construction technology and quality control standards of steel tube support reinforcement technology,the following main conclusions and innovations have been achieved:(1)Multiple segmentation control grouting vertical steel tube reinforcement support technologyThrough structural improvement,the joint reinforcement and support function of micro-pile retaining and grouting reinforcement of rock and soil body is realized.This paper reveals the combined mechanism considering the multiple effects of "multi-row steel flower tube pile","soft geotechnical grouting reinforcement","prestressing anchor cable anchorage".An innovative design and calculation method for finite difference of pile body is proposed,which improves the calculation accuracy.(2)Multiple segmentation control grouting oblique prestressed steel anchor pipe reinforcement technologyThrough the structural improvement,the joint effect of slope anchoring and grouting reinforcement of rock and soil is realized.The design method of multi-section control grouting oblique prestressed steel anchor pipe frame considering grouting effect is proposed.(3)Grouting process and quality control standardsBased on the above two steel tube reinforcement techniques,the construction technology of sectional split grouting is proposed,and the “range control,segmentation control and pressure control” of split grouting are realized.The grouting amount and grouting pressure are given.The determination methods of key design parameters such as first and second grouting interval,sealing length and grouting hole spacing were established,and quality inspection methods such as core drilling,pile investigation and non-destructive testing were established;quality control standards were established.(4)Application demonstrationThe application of landslide remediation projects such as Guangdong Guangle Expressway,Guangzhou North Third Ring Road and Chaohui Expressway shows that the technology is applied to the geological stratum,high liquid limit soil and other complex geotechnical conditions,and the engineering effect is good.It has outstanding advantages such as safety,durability,economical rationality and quick construction.