Abstract
For mountainous highway engineering, the local utilization of earth-rock materials for roadbed filling can significantly reduce transportation costs and improve resource utilization efficiency. However, earth-rock mixed fill often faces the following problems in engineering applications: (1) The rock mass excavated during construction generally has large particle sizes, and the roadbed fill material exhibits non-uniform particle sizes. The earth-rock mixture exists in a "dense-suspension structure" state, making it difficult to achieve full compaction using conventional methods; (2) Compaction degree detection methods such as the ring knife method and sand cone method specified in roadbed standards are applicable to fine-grained soils, whereas earth-rock mixed fill roadbeds constitute heterogeneous fill materials that differ substantially from fine-grained soils in terms of particle size distribution, particle size, moisture content, pore distribution, and compaction characteristics. Consequently, conventional compaction quality detection methods and evaluation standards cannot accurately characterize the compaction quality of earth-rock mixed fill roadbeds. To address these issues, this study developed an intelligent compaction system for earth-rock mixed fill roadbeds, comprising both hardware components and software control. The hardware primarily includes a high-precision positioning system, compaction degree sensors, and an intelligent compaction navigation platform; the software mainly consists of an intelligent control system for vibratory rollers and a data processing center. Focusing on the new intelligent compaction equipment, field experiments were conducted to investigate the intelligent compaction construction technology for earth-rock mixed fill roadbeds. Based on the intelligent compaction platform, technical parameters of the roller, satellite ground reference station parameters, engineering information, and construction technology standards were acquired in real time. By monitoring compaction process parameters, the control of compaction degree, compaction stability, and compaction uniformity was achieved, and a comprehensive set of intelligent compaction construction technologies for earth-rock mixed fill was summarized and established. Research on quality detection and evaluation standards for earth-rock mixed fill roadbed construction based on intelligent compaction was performed to determine the target value standard for intelligent compaction of roadbeds. Through field investigation and testing, a verification method for the correlation between intelligent compaction detection values and conventional compaction detection values of roadbeds was investigated, and a linear regression model was established. The research findings integrate mechanical engineering, surveying, electronic information, and civil engineering disciplines. Through the development and application of the intelligent compaction system, high-quality, information-based construction of earth-rock mixed fill roadbed compaction was realized.
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Preamble
Research on Intelligent Compaction Quality Control Methods for Soil-Rock Mixed Subgrade and Their Engineering Application
Chengze Han¹,², Qingyu Zhang¹,², Shen Zuo¹,², Jin Li¹,²
¹Shandong Key Laboratory of Technologies and Systems for Intelligent Construction Equipment, Shandong Jiaotong University, Jinan, Shandong 250357, China
²School of Transportation and Civil Engineering, Shandong Jiaotong University, Jinan, Shandong 250357, China
Abstract
For mountainous highway projects, utilizing local soil-rock materials for embankment construction can significantly reduce transportation costs and improve resource efficiency. However, soil-rock mixed fill materials face several challenges in engineering applications. First, excavated rock particles are typically large, resulting in non-uniform particle sizes in the subgrade fill. This places the soil-rock mixture in a "dense-suspension structure" state that is difficult to compact fully using conventional methods. Second, standard compaction testing methods specified in subgrade codes—such as the ring knife method and sand cone method—are designed for fine-grained soils. Soil-rock mixed subgrade represents a heterogeneous fill material that differs substantially from fine-grained soils in terms of particle composition, size distribution, moisture content, pore distribution, and compaction characteristics. Consequently, conventional compaction quality testing methods and evaluation criteria cannot accurately characterize the compaction quality of soil-rock mixed subgrades.
To address these issues, this study developed an intelligent compaction system for soil-rock mixed subgrades comprising both hardware and software components. The hardware primarily includes a high-precision positioning system, compaction sensors, and an intelligent compaction navigation platform. The software consists mainly of an intelligent control system for vibratory rollers and a data processing center. Field tests were conducted using this new intelligent compaction equipment to investigate the construction process for soil-rock mixed subgrade intelligent compaction. Based on the intelligent compaction platform, real-time acquisition of roller technical parameters, satellite ground base station parameters, project information, and construction process standards was achieved. By monitoring compaction process parameters, control over three critical aspects—compaction degree, compaction stability, and compaction uniformity—was implemented, resulting in a comprehensive intelligent compaction construction process for soil-rock mixed subgrades.
This research also investigated quality inspection and evaluation standards for soil-rock mixed subgrade construction based on intelligent compaction. Target value standards for intelligent compaction were established, and through field investigations and testing, a validation method for correlating intelligent compaction measurements with conventional compaction measurements was developed, leading to the establishment of a linear regression model. This study integrates mechanical engineering, surveying, electronic information technology, and civil engineering disciplines. Through the development and application of the intelligent compaction system, high-quality, information-based construction of soil-rock mixed subgrade compaction has been realized.
Keywords: soil-rock mixed subgrade; intelligent compaction system; quality control