Environmental risk assessment for impact pile driving requires characterization of the radiated sound field. Damped cylindrical spreading (DCS) describes propagation of the acoustic Mach cone generated by striking a pile and predicts sound exposure level ($L_E$) versus range. For known water depth and sediment properties, DCS permits extrapolation from a measurement at a known range. Impact assessment criteria typically involve zero-to-peak sound pressure level ($L_{p,\text{pk}}$), root-mean-square sound pressure level ($L_{p,\text{rms}}$), and cumulative sound exposure level ($L_{E,\text{cum}}$). To facilitate predictions using DCS, $L_{p,\text{pk}}$ and $L_{p,\text{rms}}$ were estimated from $L_E$ using empirical regressions. Using a wind farm construction scenario in the North Sea, DCS was applied to estimate ranges to recommended thresholds in fishes. For 3500 hammer strikes, the estimated $L_{E,\text{cum}}$ impact ranges for mortal and recoverable injury were up to 1.8 and 3.1 km, respectively. Applying a 10 dB noise abatement measure, these distances reduced to 0.29 km for mortal injury and 0.65 km for recoverable injury. An underlying detail that produces unstable results is the averaging time for calculating $L_{p,\text{rms}}$, which by convention is equal to the 90%-energy signal duration. A stable alternative is proposed for this quantity based on the effective signal duration.

中文翻译：

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应用阻尼圆柱展开来评估冲击桩打捞鱼的伤害阈值范围。

冲击桩打桩的环境风险评估需要表征辐射声场。阻尼圆柱扩展（DCS）描述了通过撞击桩而产生的马赫锥形声波的传播，并预测了声暴露水平（${\mathrm{大号}}_{Ë}$）与范围。对于已知的水深和沉积物属性，DCS允许从已知范围内的测量值推断。影响评估标准通常涉及零峰声压级（${\mathrm{大号}}_{p，\text{pk}}$），均方根声压级（${\mathrm{大号}}_{p，\text{均方根}}$），以及累积的声音暴露水平（${\mathrm{大号}}_{Ë，\text{兼}}$）。为了便于使用DCS进行预测，${\mathrm{大号}}_{p，\text{pk}}$ 和 ${\mathrm{大号}}_{p，\text{均方根}}$ 是根据 ${\mathrm{大号}}_{Ë}$使用经验回归。使用北海的风电场建设方案，DCS被用于估算鱼类的推荐阈值范围。对于3500次锤击，估计${\mathrm{大号}}_{Ë，\text{兼}}$致命和可恢复伤害的影响范围分别达1.8公里和3.1公里。采用10 dB的消减噪音措施，这些距离对于致命伤害减少为0.29 km，对于可恢复伤害减小为0.65 km。产生不稳定结果的基本细节是计算的平均时间${\mathrm{大号}}_{p，\text{均方根}}$，按照惯例，它等于90％能量信号的持续时间。提出了一种基于有效信号持续时间的稳定替代方案。