The pilot reported that upon entering the airport traffic pattern, he remained at a higher altitude than normal on downwind and base legs due to helicopter traffic. Upon turning final, the approach angle to the runway was steeper than normal, and the airplane was still high. The pilot stated that due to the steeper approach angle he misjudged the landing flare; the airplane landed hard, bounced, and began to porpoise. As he attempted to abort the landing, the airplane veered to the right and landed in the dirt adjacent to the runway. Subsequently, the airplane nosed over, which resulted in structural damage to both wings, vertical stabilizer, and rudder. The pilot reported no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation.