Anchor plates have been widely used in transferring the load from the super-structure to the weak soil, TV towers, large suspension bridges, aircraft, and other structures have a short construction time. ^{2, 4} A comprehensive research has been introduced to test the pullout bearing capacity of anchor plates by using different research methods, such as theoretical studies, ^{3, 4} numerical simulations, ^{5, 6} and model texts. ^{7, 8} It seems to improve the conditions of the subsoil that would be used with the anchor plate. ⁹ compared the results that were predicted by different theoretical theories for shallow anchors and obtained a wide disparity. ¹⁰ they have been compared their experimental results in a deep anchors tests with the theoretical results for Meyerhof (1973) and Ovesen (1964), they obtained a large difference, especially in the case of dense sand. The boundaries between a shallow and a deep anchor plate expressed as a critical embedment ratio. Many researchers ¹¹ showed that the critical embedment ratio (H/B)cr. different from (2.5 to 9) depending upon anchors geometry and relative density of the soil. The group was taken with (S = 4D) C/C and acts as a large anchor (single anchor). ¹² The sandy soil has been improved by much research such as enhancing the bearing capacity of the sandy soil by reinforcing the soil by Geogrid layers and finding the optimum embedment depth. ^{32– 34} The increase of (z/B) above 1.5 has no effect on the bearing capacity. ¹³ While improving the loose sandy soil by the same material, the results for the bearing capacity increase by (21%) at one layer and (47.5%) for two layers. ¹⁴ On the other hand ¹⁵ stabilized the dune sand by cement kiln dust CKD the results of the tests showed that angle of internal friction and shear strength decreased and became almost constant after (14) day of the curing. Also the existing water with sandy soil affects more than the gravel. ^{16, 17} considered the sand soil as improved material in clayey soil ²³ by using the numerical analysis for the transition (critical) embedded ratio from shallow (breakaway) to deep (no breakaway) equal (H/D = 2.5) in dynamic loading embedded plate anchor (DEPLA). From the previous experimental studies ^{24– 28} that indicated the length difference between the shallow and depth anchor plate in a static loading, depth that anchor transits from shallow to depth it’s a critical depth with consideration to the embedded ratio(H/B). Many other studies have concluded an approximately (H/B = 6) at which the anchor transit from shallow to deep. Another conclusion for the phenomenon ²⁹ that found the surface failure related to the shape of ground level when the anchor plate that subjected to loading, if the surface failure extend to the ground level will be a shallow anchor, while the deep anchor will be such as a balloon shape and didn’t extend to the ground surface. Whilst ³⁰ searched that by depending upon the relative density for the soil in very loose sand and very soft clay be at depth (2D), for stiff clay (5D) and (10D) in very dense sand ³¹ showed the critical depth (H/B = 5) as a transitional ratio ³² suggested the critical depth in a soft clay depending on the size, shape of the anchor and the soil parameters in strip anchors (H/B = 3), and for circular anchors (H/B = 1.75). As a result the critical depth depends upon the angle of internal friction, unit weight and relative density of the soil.

By using a steel container (850*850*850) mm with a unique glass face to observe the failure mode of the anchor. The scale effect of the physical model depending on the modified Soil cone Theory ¹⁸ as shown in ( Figure 1).

While used in the test steel anchor with square plate (D), (3x3) cm with different embedded depth (H). At each anchor bar there is a welded screw to facilitate connection with the load cell and the electrical lever to lift the anchor plate and also another screw between the load cell and the electrical lever. The line groups (1x2), (1x3), (1x4) & (1x5) welded each group by horizontal steel bar with (S = 4D) as shown in ( Figure 2).

The vertical displacements were recorded by two electronics (Lvdt) as shown in ( Figure 3).

Soil that’s used in the experimental work carried out from the Annajaf sea region. Standard laboratory physical and chemical tests for the soil have been established according to ASTM. Grain size distribution method Sieve analysis test was performed according to the ¹⁹ (ASTM. D422). The results of the sieve analysis test are listed in Table 1.

Proctor test method ²⁰ (ASTM. D 698). This test is performed according to specification ASTM D 698 From the curve of the compaction the maximum dry density is 17.74 kN/m ³. Unit weight of soil in place of a field unit weight is carried out by the sand-cone method ²¹ (ASTM. D 1556). The test was conducted in the site of the soil is Najaf sea area and the unit weight and water content of the soil in the site are 15.51 kN/m ³ and 2% respectively. Direct shear test three samples were tested in shear box test under normal stresses of (15.7, 31.4 and 54.9 kN/m ²) by using ASTM D3080. The cohesion and angle of internal friction of soil are 0 kN/m ² and Ø = 31 deg. Table 2 shows the chemical properties of the soil.

The soil has been prepared in the physical model by using a raining method to obtain a loose state for the sandy soil with a calculated height with a loose unit weight as shown in ( Figure 4).

And analyze the above data by using the SPSS program and depending on many modes of analysis and the most accurate higher regression (R = 0.984) as shown in the analysis data in the below Table 3. H = 0.946 ∗ Dr % + 0.013 ∗ Dr % 2 − 1.001 (1)

Where

H: falling height in CM

So at Ø = 30, the Dr% = 35%, then H = 48 cm according to Equation (1). The below Table 4 shows the physical Properties for the emulsion asphalt.

After installation the set up the anchor plate is tested by uplift loading using an electrical lever and load cell to measure the load capacity and Lvdt to record the average vertical displacement until the anchor plate reaches the failure state as shown in ( Figure 5).

The load that the anchor plate failed at conceded a maximum load and which before it less than the failure load. Each test is repeated at least four times with a difference less than 5% for considering the results of each test. Every test was embedded at depths (2D, 3D, 4D, 5D, 6D, 7D & 8D) and loading till failure in single and line groups square anchor plates (1x2), (1x3), (1x4) & (1x5) in sandy soil. The bed of the sandy soil at depth 30 cm inside the model and below the tip of the anchor and the remaining layers with 10 cm depth for each layer as shown ( Figure 6).

The critical depth of the anchor plate increases with the densification of the soil. The critical depth separated clearly in the group anchor more than the single anchor. The close spacing between the anchors try to make the behaviour of the group anchor as a large single anchor at S = 4D. The increasing number of the anchor plate increases in the uplift resistance and decreases in the vertical displacement. The failure surface with the soil of the anchor plate as a rectangular shape like the friction theory. The optimum ratio for the improving was 4% because after this ratio the values of the internal friction decrease while the cohesion increases but this increment corresponds to decreasing the internal friction. The improving ratio in the shallow anchor higher than in the deep anchor. The improvement rate was higher when the asphalt emulsion was used with a cure for 21 days than when the emulsion was used for 7 days, and the improvement rate was also smaller in the deep anchor group than in the shallow single anchor.

In this research, ethical approvals were not required because the research was conducted on purely engineering materials, inanimate materials that are not inherently ethical. Nevertheless, the research complies with the requirements of engineering research.

All authors have reviewed and approved the final version of the manuscript and consent to its publication.