*2.3. Raw Materials*

Ordinary Portland cement, sand, gravel, tap water and admixture were used to prepare concrete. Ordinary Portland cement with the strength grade 42.5 (P.O 42.5) was used to prepare concrete with the strength grade of C30, and its parameters met the requirements of Chinese specification (GB 175-2020) [16]. The fine aggregate was the ordinary river sand produced locally in Chongqing, and the fineness modulus was 2.78. The coarse aggregate was continuous graded limestone gravels, and the particle size range was 5~20 mm. The water was tap water, and GJ-1 superplasticizer with a water reduction of 22% was selected as the additive. The mix proportion of the pile concrete was calculated according to the Chinese specification (JGJ 55-2011) [17], and is listed in Table 5. The measured performances of concrete and steel bars are displayed in Tables 6 and 7, respectively.

**Table 5.** Mix Proportions.


**Table 6.** Measured performances of concrete.


**Table 7.** Measured performances of steel bars.


*2.4. Device System for the Model Test*

In order to simulate the cantilever anti-slide pile subjected to the trapezoidal load, a test system for the bearing performance of the cantilever anti-slide pile under the trapezoidal load was independently developed and fabricated, as shown in Figures 4 and 5. The system is mainly composed of the test pile fixing system, thrust loading system, and data acquisition system. These systems are introduced as follows.

**Figure 4.** Diagrammatic sketch of test device (unit: mm).

**Figure 5.** Load test on the test pile.
