To explore the influence of rock shape on rolling distance and effectively mitigate rockfall hazards, the following research was conducted. Factors influencing the rolling distance of rocks were determined through model experiments, and the mechanics of rolling resistance were analyzed. The coefficient RF, reflecting the ease of rock rolling, and the shape parameter ψ, quantifying the rolling distance, were proposed. By incorporating the shape parameter into kinematic equations, formulas for calculating the rolling distance of rocks with varying shapes on diverse ground characteristics were derived. These formulas underwent validation using data from model experiments, revealing minimal disparities between the experimental and calculated values. Irregularities on the rolling surface, commonly referred to as “steps” due to the differences in surface hardness among various materials, as well as deviations and shifts in the rolling axis during rock movement, were identified as the primary factors influencing rolling distance and contributing to calculation errors. Combining these deviations for rocks of distinct shapes with theoretical formulas enabled the determination of the range of influence of rock rolling at various velocities, offering valuable insights for assessing areas prone to rockfall hazards.

The pocket penetrometer has become an ideal tool for the rapid testing of soil parameters in the field due to its portability, ease of use, and cost effectiveness, but there is still room for improvement in its accuracy. In this study, a penetration test on red clay was investigated by increasing the penetration depth and combining the self-designed penetrometer, sample preparation method, and data analysis method. The improved sample preparation technique performs well in improving sample uniformity and preparation efficiency. The quantitative processing of the penetration curves improves the objectivity and accuracy of the test results. The penetration test results of various reshaped soils showed that the relationships between liquidity index, shear strength, and penetration resistance were less affected by the liquid–plastic interface. In addition, the penetration test results of remolded soils and in situ soils showed that the empirical formulas are still informative in evaluating the shear strength of soils despite the differences in the test soils.

In karst regions, the drilling into the rock layer is restricted, if the construction site has a thick overburden and a small upper load. The evaluation of karst development features beneath the site becomes a common technical difficulty in building...

The long-term high-pressure consolidation test, of which the maximum consolidation pressure is 6 MPa and the longest consolidation duration is 34 months, is selected to simulate the deformation characteristics of the main compression soil layer (depth of 100 ~300 m) based on the study of the deep foundation pit silty clay located in Xiaozhai subway station in Xi'an City. The test results shows that Terzaghi's one-dimensional consolidation theory of soil is no longer applicable to the soil consolidation calculation and prediction as the consolidation stress exceed 4.8MPa; under the pressure of 6 MPa, the rheological deformation accounts for about 90% of the total deformation, and the deformation shows no signs of stopping after compression for 953 days; when the stress is reduced or removed, most of the compression deformation of soil is not recoverable.

In order to study the influence of falling rock shapes on their rolling characteristics and to determine the optimization of falling rock protection design, a series of research experiments were conducted. Model experiments were designed to explore the rolling characteristics of rockfalls with different shapes. Based on the experimental results, it was found that the slenderness ratio, center of gravity, and rotational inertia of the rockfalls can affect their rolling characteristics, leading to swaying and changing the rolling axis during the rolling process, thereby affecting their rolling speed. Building upon these findings, an analysis of the formation mechanism of rolling resistance was conducted. It was determined that the primary cause of energy loss was the rolling resistance arm formed with the rolling surface during rockfall motion. A shape parameter was proposed to quantify the rolling resistance. These parameters were incorporated into a kinematic formula that considered the influence of rockfall shape, slope, and slope roughness on the rolling speed. Combined with the offset and initial position of the rockfall, the formula could be used to calculate the rolling speed and impact energy in the rolling region at any position in the region. The calculation formula was validated using model experimental data, and the results showed that the error between the experimental and calculated values was small. The error was corrected based on the experimental data. After on-site testing and verification, it could provide reference for the management of rockfall disasters.

In order to study the influence of falling rock shape on its rolling characteristics and realize the optimization of falling rock protection design, the following research was carried out. Design model experiments to explore the rolling characteristics of different shapes of rockfalls. Based on the experimental results, it was found that the slenderness ratio, center of gravity, and rotational inertia of the rockfalls can affect their rolling characteristics, leading to swaying and changing the rolling axis during the rolling process, thereby affecting their rolling speed. On this basis, the formation mechanism of rolling resistance is analyzed, and the main cause of energy loss is the rolling resistance arm formed with the rolling surface during rockfall rolling, and a shape parameter to quantify the rolling resistance is proposed. The parameters are substituted into the kinematic formula, in which the influence of the rockfall shape, slope and slope roughness on the rolling speed is considered. Combined with the offset and initial position of the rockfall, the formula can be used to calculate the rolling speed and impact energy in the rolling region and any position in the region. The calculation formula was validated using model experimental data, and the results showed that the error between the experimental and calculated values was small. The error was corrected based on the experimental data. After on-site testing and verification, it can provide reference for the management of rockfall disasters.