The experiment of explosion wave propagation in saturated soil is accomplished in Φ900 plane blast load generator. In this paper

the explosion wave propagation in free field and its reflection on the rigid boundary are investigated. The experimental results indicate that the air content in saturated soils plays the most important role in the wave propagation; the peak incident pressure might increase alone with the depth of soil specimen; the reflection coefficient might be larger than 2. The laws of explosion wave propagation in saturated soils are very different from that of unsaturated soils according to experimental results

special attention must be devoted to the determination of the loading on the structure buried in the saturated soils. Two main experimental phenomena are expatiated further: 1. The reflection coefficient on the rigid obstacle The incident wave loading of free field cannot be measured directly on the bottom

consequently

the reflection coefficient canno

t be calculated directly. As a makeshift

the free field stress P3 is determined by using extrapolation method

a sample point is removed by its illogicality in the first loading. The value of P

4

P

3

in the bottom is the reflection coefficient on the rigid obstacle. A tendency to an increase in the reflection coefficient is observed

the maximum is 2.259

and greater than 2.0. It is noticed that the real value of P

4

must be greater than the current value due to the peeling of some soft rings

and the value of P

4

P

3

in the bottom should be increased. In a word

the reflection coefficient in the rigid obstacle might be greater than 2.0. This is coincident with the results of saturated soils experiment by Huang

and saturated porous medium experiment by V. E. Dontsov

. 2. The "Inverse-attenuation" Phenomenon The inverse-attenuation phenomenon is defined as the increasing of the incident wave stress in the direction of the wave propagation in the free field

it is easier to appear in partially saturated soils than in the unsaturated soil and dry sands. The necessary condition is an increase of the acoustic impedance in the direction of the wave propagation

if the effects of the plasticity and viscosity etc. are relatively weak

the combined actions will result in the rising of the case. For unsaturated soils and dry sands

the action of the later factor is very great

the case is seldom seen. By contraries

for the partially saturated soils

the increase of saturation in the depth direction might be remarkable

and the compressibility decreases proportionally

compared with the unsaturated soils

the effects of the plasticity and viscosity etc. is relatively weak.