Abstract
In view of the fact that there is in shortage of superior roadbed fillers in gobi and desert areas and based on the economical and environment-friendly concept, the cement-improved silty fine sand will be used as the roadbed filler of a railway construction project, which has the engineering characteristics of difficult compaction of local silty fine sands and loose structure, within the territory of Jiuquan, Gansu Province.The test indicated that the actual silty fine sands presented relatively concentrated particle sizes in this project, the particle composition was uniform and difficult to compact. The 7d saturated unconfined compressive strength of the cement-improved silty fine sand filler was correlated with the cement content, curing age and compaction coefficient, and also showed a good linear fitting relation with the cement content. As the delay time of sample molding was lengthened, the 7d saturated unconfined compressive strength of the samples was gradually reduced, and the strength retention rate had a favorable fitting relation with the delay time of sample molding. The compaction coefficient was detected using the sand-cone method in the field compaction test, and on this basis, the “ex post detection” method was proposed to detect the compaction coefficient of this special type of fillers.
Highlights
For a railway construction project within the territory of Jiuquan, Gansu Province, the area that the rail track passes through mainly presents the topographic forms of desert and gobi
A laboratory test of the silty fine sands collected on the field and cement-improved silty fine sands was firstly carried out, the value range and change laws of their physical and mechanical indexes were obtained, and on this basis, the feasibility of usage of cement-improved silty fine sands as the roadbed filler was verified through the field compaction test
The field construction of improved soil mainly experiences the mixing-spreading-compaction stages, the delay time of cement-improved soil refers to the time duration from the addition of the cement into the mixture until the completion of compaction, and it will generate a certain influence on the compaction quality and strength (7d saturated unconfined compressive strength) of cement-improved soil, so the time delay of improved soil is of great importance to the control of construction nodes and construction quality
Summary
For a railway construction project within the territory of Jiuquan, Gansu Province, the area that the rail track passes through mainly presents the topographic forms of desert and gobi. Through the comprehensive comparison and selection, the local cement-improved silty fine sands along the railway can be used as the roadbed fillers to lower the engineering cost and accelerate the project progress. The relationships of strength of cement-improved silty fine sand with the curing age, cement content, compaction coefficient and delay time of sample molding were summarized. Zhang B W [2] summarized the basic physical and mechanical properties of cement-improved silty fine sands through a laboratory test, and analyzed its durability. Tang Y L [3] analyzed and summarized the influencing factors of cement-improved silty fine sands. The laboratory test and field test were combined in this paper to systematically analyze the pavement performance of cement-improved silty fine sand
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
