非水平坡顶的挡土墙主动土压力
v0.1.2计算方法：GB50330-2013公式6.2.3
$$ E_a=\frac12{\gamma}H^2K_a$$ $$ K_a = \frac{sin(\alpha+\beta)}{sin^2{\alpha} sin^2(\alpha+\beta-\varphi-\delta)} \left\{ K_q[sin(\alpha+\delta) sin(\alpha-\delta) + sin(\varphi + \delta) sin(\varphi-\beta)] + 2{\eta} sin{\alpha} cos{\varphi} cos(\alpha+\beta-\varphi-\delta) - 2\sqrt{K_q sin(\alpha+\beta) sin(\varphi-\beta) + sin{\alpha} cos{\varphi}} \times \sqrt{K_q sin(\alpha-\delta) sin(\varphi+\delta) + sin{\alpha} cos{\varphi}} \right\} $$ $$ K_q=1+\frac{2qsin{\alpha}cos\beta}{{\gamma}Hsin(\alpha+\beta)}$$ $$ \eta=\frac{2c}{{\gamma}H} $$
计算结果：