The correct answer is D. All the above.
In a cantilever retaining wall without a heel slab, the thickness of the stem is kept same throughout, the base slab is made 10 cm thicker than the stem, and the width of the base slab is kept 0.7 time the total height of the wall.
The thickness of the stem is kept same throughout to ensure that the wall is able to withstand the lateral loads from the soil. The base slab is made 10 cm thicker than the stem to provide additional support for the wall and to prevent it from overturning. The width of the base slab is kept 0.7 time the total height of the wall to provide a large enough base area to distribute the load from the wall evenly.
Here are some additional details about each of these aspects of a cantilever retaining wall without a heel slab:
- The thickness of the stem is typically kept between 15 and 30 cm, depending on the height of the wall and the type of soil.
- The base slab is typically made 10 cm thicker than the stem, but this can vary depending on the specific design of the wall.
- The width of the base slab is typically kept between 0.7 and 1.0 times the total height of the wall, but this can vary depending on the specific design of the wall.
It is important to note that these are just general guidelines, and the specific design of a cantilever retaining wall without a heel slab will vary depending on the specific site conditions and the requirements of the engineer.