Statement 1: In a helical reinforced concrete column, the concrete core is subjected to tri-axial state of stress.

Explanation:
In a helical reinforced concrete column, helical reinforcement is provided in the form of closely spaced helical bars. These helical bars are wrapped around the concrete core of the column. This helical reinforcement enhances the load-carrying capacity and ductility of the column.

The helical reinforcement in the column acts as a confinement mechanism for the concrete core. It prevents the lateral expansion of the concrete core and provides confinement to the core under axial loading. This confinement results in the development of tri-axial state of stress in the concrete core.

The tri-axial state of stress means that the concrete core experiences compressive stresses in all three directions - axial (along the length of the column), circumferential (around the circumference of the column), and radial (inward from the outer surface of the column). This tri-axial state of stress is beneficial as it increases the strength and stiffness of the column, making it more resistant to failure.

Therefore, statement 1 is correct.

Statement 2: Helically reinforced columns are very much suitable for earthquake resistant structures.

Explanation:
Helically reinforced columns offer several advantages in terms of earthquake resistance. These advantages are as follows:

1. Increased ductility: The helical reinforcement provides confinement to the concrete core, which enhances its ductility. Ductility is the ability of a material to deform plastically before failure. In an earthquake, buildings undergo significant lateral displacements and deformations. The increased ductility of helically reinforced columns allows them to withstand these deformations without collapsing.

2. Improved energy dissipation: The confinement provided by the helical reinforcement increases the energy dissipation capacity of the column. During an earthquake, the energy generated by the ground motion needs to be absorbed and dissipated by the structure to prevent damage. The helical reinforcement helps in dissipating this energy, thereby reducing the impact on the structure.

3. Enhanced load-carrying capacity: The confinement effect of the helical reinforcement increases the load-carrying capacity of the column. This allows helically reinforced columns to resist the higher loads generated during seismic events.

4. Prevention of buckling: The helical reinforcement also helps in preventing buckling of the concrete core under axial compression loads. Buckling can lead to sudden and catastrophic failure of the column. The helical reinforcement provides additional strength and stiffness to the column, preventing buckling and ensuring its stability.

Therefore, statement 2 is also correct.

In conclusion, both statement 1 and statement 2 are correct.